Well Planning

SKUA and GOCAD User Guide

Part XI: Well Planning

Published October 10, 2012

19972012 Paradigm Ltd. or its affiliates and subsidiaries. All rights reserved.The information in this document is subject to change without notice and should not be construed as a commitment by Paradigm Ltd. or its affiliates and subsidiaries (collectively, "Paradigm"). Paradigm assumes no responsibility for any errors that mayappear in this document.The Copyright Act of the United States, Title 17 of the United States Code, Section 501 prohibits the reproduction or transmission of Paradigms copyrighted material in any form or by any means, electronic or mechanical, including photocopying and recording, or by any information storage and retrieval system without permission in writing from Paradigm. Violators of this statute will be subject to civil and possible criminal liability. The infringing activity will be enjoined and the infringing articles will be impounded. Violators will be personally liable for Paradigms actual damages and any additional profits of the infringer, or statutory damages in the amount of up to $150,000 per infringement. Paradigm will also seek all costs and attorney fees. In addition, any person who infringes this copyright willfully and for the purpose of commercial advantage or private financial gain, or by the reproduction or distribution of one or more copies of a copyrighted work with a total retail value of over $1,000 shall be punished under the criminal laws of the United States of America, including fines and possible imprisonment.The following are trademarks or registered trademarks of Paradigm Ltd. or its affiliates and subsidiaries (collectively,"Paradigm") in the United States or in other countries: Paradigm, Paradigm logo, and/or other Paradigm products referenced herein. For a complete list of Paradigm trademarks, visit our Web site at www.pdgm.com. All other company or product names are the trademarks or registered trademarks of their respective holders.Alea and Jacta software under license from TOTAL. All rights reserved.Some components or processes may be licensed under one or more of U.S. Patent Numbers 5,570,106; 5,615,171; 6,765,570; and 6,690,820.Some components or processes are patented by Paradigm and/or one or more of its affiliates under U.S. Patent Numbers 5,563,949; 5,629,904; 5,838,564; 5,892,732; 5,930,730; 6,055,482; 6,092,026; 6,430,508; 6,819,628; 6,820,043; 6,859,734; 6,873,913; 7,095,677; 7,123,258; 7,295,929; 7,295,930; 7,328,139; 7,561,922; 7,584,056; 7,711,532; and 7,844,402. In addition, there may be patent protection in other foreign jurisdictions for these and other Paradigm products.All rights not expressly granted are reserved.Third-party software notices are located at www.pdgm.com/thirdparty/.

iii

Before You Begin

These topics provide information to help you use the Basic Well Planning and Side Track and Collision Risk modules with Paradigm SKUA and Paradigm GOCAD. These modules integrate geologic, geophysical, reservoir, and existing well data with drilling and platform planning in a true 3D environment. With the Basic Well Planning module you have access to the Well Planning Workflow that guides you through the process of planning and evaluating individual wells, drilling platforms, and sidetracks as well as determining and evaluating costs and the risks associated with drilling wells.

Initial development of this product was done in collaboration with the BP Center for Visualization from an ARCO project started in 1998.

About This DocumentTo work with these products, we recommend that you have good working knowledge of SKUA or GOCAD.

Before You Beginiv SKUA and GOCAD Paradigm 2011With Epos 4.1 Data Management

vContents

Contents


Before You Begin ........................................................................................ iii

About This Document ................................................................................................. iii

Chapter 1 Introduction to Well and Platform Planning ............................................1-1

1.1 What Is Basic Well Planning? ......................................................................... 1-2

1.2 What Is Side Track and Collision Risk? ........................................................... 1-3

1.3 Tour of the Well Planning Interface ................................................................ 1-4

1.3.1 Workspace for Well Planning ............................................................ 1-5

1.3.2 Well Planning Objects....................................................................... 1-6

1.3.3 Well Planning Shortcut Menus .......................................................... 1-9

1.3.4 Well Planning Editing Tools ..............................................................1-10

1.3.5 Well Planning Style Toolbars ............................................................1-10

1.3.6 Drilling Planner Category in the Style Dialog Box ..............................1-11

1.4 Concepts in Well Planning ...........................................................................1-12

1.4.1 Points on the Well Path ...................................................................1-12

1.4.2 Sidetracks .......................................................................................1-16

1.4.3 Drilling Platforms ............................................................................1-16

1.4.4 Well Path Uncertainty ......................................................................1-20

1.4.5 Collision Risk ..................................................................................1-20

Chapter 2 Getting Started with Well Planning .........................................................2-1

2.1 Preparation for Well Planning ........................................................................ 2-2

2.2 Starting or Continuing a Well Planning Workflow .......................................... 2-3

2.3 Selecting Tasks in Well Planning .................................................................... 2-4

2.4 Setting Up Drilling Parameter Templates ........................................................ 2-9

2.4.1 Templates in Well Planning ..............................................................2-10

Contentsvi SKUA and GOCAD Paradigm 2011With Epos 4.1 Data Management

2.4.2 Accepting the Default Drilling Parameters........................................ 2-11

2.4.3 Editing Drilling Parameter Templates ............................................... 2-12

2.4.4 Validating, Resetting, and Initializing Drilling Parameters .................. 2-22

2.4.5 Completing the Drilling Parameter Templates Task ........................... 2-23

Chapter 3 Planning Targets, Wells, Platforms, and Sidetracks ................................. 3-1

3.1 Managing Targets ......................................................................................... 3-2

3.1.1 Selecting Steps in Target Management .............................................. 3-3

3.1.2 Creating Targets ............................................................................... 3-4

3.1.3 Editing Targets ................................................................................. 3-8

3.2 Planning Wells ............................................................................................ 3-14

3.2.1 Selecting Steps in Well Planning ...................................................... 3-14

3.2.2 Creating Wells ............................................................................... 3-15

3.2.3 Editing Wells .................................................................................. 3-18

Displaying Well Editing Points ......................................................... 3-19

Manually Editing a Well Path .......................................................... 3-20

Editing the Drilling Parameters for an Individual Well ....................... 3-22

Completing the Edit Wells Step ....................................................... 3-24

3.3 Planning Drilling Platforms .......................................................................... 3-25

3.3.1 Selecting Steps in Platform Planning................................................ 3-26

3.3.2 Creating Drilling Platforms .............................................................. 3-27

3.3.3 Editing Drilling Platforms ................................................................ 3-30

Editing Drilling Parameters for an Individual Platform ....................... 3-30

Completing the Edit Platforms Step ................................................. 3-31

3.4 Planning Sidetracks ..................................................................................... 3-32

3.4.1 Selecting Steps in Sidetrack Planning............................................... 3-33

3.4.2 Creating Sidetracks and Performing Reach Analyses ......................... 3-34

3.4.3 Editing Sidetracks ........................................................................... 3-39

Editing the Drilling Parameters for an Individual Sidetrack ................ 3-39

Completing the Edit Sidetracks Step ................................................ 3-40

Chapter 4 Evaluating Drill Plan Quality and Reporting Results ............................... 4-1

4.1 Checking the Quality of Your Drilling Plans .................................................... 4-2

4.1.1 Displaying Uncertainty, Collision Risk, and Curvature Violations .......... 4-3

4.1.2 Extracting Information Along a Well Path .......................................... 4-6

4.1.3 Completing the Quality Control Task ................................................. 4-8

4.2 Reviewing and Exporting the Results of Your Drilling Plans.............................. 4-9

Appendix A Cost Model and Uncertainty Computations ............................................ A-1

A.1 Cost Model Equation .................................................................................... A-2

A.2 Uncertainty Equations ................................................................................... A-3

1-1

1Introduction to Well and Platform Planning

In this chapter "What Is Basic Well Planning?," page 1-2

"What Is Side Track and Collision Risk?," page 1-3

"Tour of the Well Planning Interface," page 1-4

"Concepts in Well Planning," page 1-12

Overview Basic Well Planning and Side Track and Collision Risk are modules for Paradigm SKUA and Paradigm GOCAD for planning and editing stand-alone wells, drilling platforms, and sidetrack wells. This introduction provides an overview of the areas of the interface you can use to create drilling plans and some terminology and concepts related to well and platform planning.

Introduction to Well and Platform Planning1-2 SKUA and GOCAD Paradigm 2011With Epos 4.1 Data Management

1.1 What Is Basic Well Planning?Basic Well Planning is an optional module for SKUA and GOCAD that integrates geologic, geophysical, reservoir, and well data with drilling and platform planning in a true 3D environment. Being able to plan a well in direct interaction with the geologic model is of great value. For example, you can create well markers where horizons intersect a planned well and extract synthetic logs from geologic data along the well path.

By creating and editing targets, platforms, and wells in real time, multi-disciplinary teams can work through several planning scenarios, consider all critical factors, and generate high-level plans that can be readily updated to accommodate changing conditions. This combination of data integration, interactive editing, and collaborative workflow can greatly reduce cycle times in planning wells and improve the overall economics of development. Pilot projects have demonstrated reductions in cycle times from several months to a week or less.

Typically, when you plan wells or drilling platforms, you must perform some or all of the following tasks depending on your goals:

1 Gather existing data and define the engineering criteria.

2 Identify target spots you want to reach during drilling.

3 Plan individual wells or drilling platforms to reach the identified targets.

4 Evaluate the drilling plan including examining the costs associated with each well path.

5 Modify targets, paths, and locations as necessary to minimize costs.

The Basic Well Planning module organizes these steps into a workflow, called Well Planning, that is integrated in SKUA and GOCAD.

Accessing Basic WellPlanning

If you have purchased the Basic Well Planning module, you can load it when you start SKUA and GOCAD. For information about how to add modules to a new or existing project, see Part I: Getting Started, "Choosing Modules for a Project" on page 1-11.

You can pick target locations in 3D on any type of data within a reservoir property model or seismic volume.


1.2 What Is Side Track and Collision Risk? 1-3User Guide

1.2 What Is Side Track and Collision Risk?Side Track and Collision Risk is specialized module for SKUA and GOCAD that builds on the functionality of the Basic Well Planning module. Side Track and Collision Risk integrates optional steps into the Well Planning Workflow for planning sidetrack wells and enhancing quality control of your drilling plans.

With the Side Track and Collision Risk module, you can create well paths that branch off of existing wells to reach nearby targets. You can also determine and evaluate the positional uncertainty of each well path and the risk of intersecting existing wells or other planned wells. You can use this additional information to evaluate and then modify targets, well paths, and well or platform locations as necessary to minimize risks. For more information about uncertainty and risk, see "Well Path Uncertainty" on page 1-20 and "Collision Risk" on page 1-20.

Accessing Side Trackand Collision Risk

If you have purchased both the Basic Well Planning and Side Track and Collision Risk modules, you can load them when you start SKUA or GOCAD. When you select Side Track and Collision Risk, the Project Module Selector automatically loads the Basic Well Planning module. For information about how to add modules to a new or existing project, see Part I: Getting Started, "Choosing Modules for a Project" on page 1-11.


1.3 Tour of the Well Planning InterfaceWhen you open a project with the Basic Well Planning module, you will find some additions to the SKUA or GOCAD interface in these areas:

Objects browser. A new geometric object, TargetSet, in the Wells object category and shortcut menus with commands specific to this object.

Unassigned Objects browser. A new geometric objects, DrillingPlatform, and shortcut menus with commands specific to this object.

Workflows browser. An additional icon called Well Planning, providing access to the Well Planning Workflow.

3D Viewer. Shortcut menus with commands specific to the well planning objects (wells, platforms, and target sets).

Toolbars. New editing tools on the Digitization/Editing toolbar and graphic styles on the Style toolbars that are specific to well planning objects. In addition, when you are working in Well Planning, two more toolbars are available: the Well Planning Style toolbar (at the bottom of the window) and the Well Planning Editing toolbar (on the right of the window), both of which are specific to the object (well, target set, or platform) selected in the workflow.

Style dialog box. New styles for wells in the Drilling Planner category in the Style dialog box.

When you also load the Side Track and Collision Risk module, you will find more additions to the interface. These additions are not as visible as those for the Basic Well Planning module because they are integrated into the existing interface. They include:

Optional steps in the Well Planning Workflow for planning sidetrack wells and displaying positional uncertainty and collision risk for planned well paths.

Commands on the shortcut menus for wells.

Graphic styles in the Style dialog box and on the Style toolbar for wells.

For more information about each of these areas of the interface, see:

"Workspace for Well Planning," page 1-5 "Well Planning Objects," page 1-6 "Well Planning Shortcut Menus," page 1-9 "Well Planning Editing Tools," page 1-10 "Well Planning Style Toolbars," page 1-10 "Drilling Planner Category in the Style Dialog Box," page 1-11

Note For information about the Base Module interface, see Part I: Getting Started, "SKUA and GOCAD Quick Tours" on page 1-20.


1.3 Tour of the Well Planning Interface 1-5User Guide

1.3.1 Workspace for Well PlanningWith the Basic Well Planning module, when you click the Well Planning icon, the Workspace displays the Well Planning Workflow (see Figure 11). This workflow acts as a guide to help you specify drilling targets; plan stand-alone wells and drilling platforms; as well as determine and evaluate the costs associated with drilling. If you have also loaded the Side Track and Collision Risk module, you can use the workflow to plan sidetrack wells and calculate and evaluate the uncertainty and risk associated with your drilling plans.

Well Planning divides the operations for planning and evaluating your drilling plans into these main tasks:

Drilling Parameter Templates. Setting up engineering criteria Target Management. Defining drilling targets Well Planning and Platform Planning. Modeling and editing wells and platforms Quality Control. Evaluating the quality of your drilling plans Results. Reviewing and exporting results

When you select one of these tasks in Well Planning, the panel at the bottom of the workflow changes to show commands and options specific to the selected task. For more information about how to get started in this workflow, see "Getting Started with Well Planning" on page 2-1.

Figure 11 Well PlanningWorkflow

Note Sidetrack Planning and some of the commands in the Quality Control task are available in Well Planning when you load the Side Track and Collision Risk module.

Select tasks to navigate through the workflow

Select options and carry out commands

Progress through the workflow, create reports, and get help


1.3.2 Well Planning ObjectsWhen you use Well Planning to plan wells and drilling platforms, you will use two new types of geometric objects, TargetSets and DrillingPlatforms and several new types of resource objects called DrillingTemplates. In addition, Well Planning creates Well objects which have some differences from standard SKUA and GOCAD wells.

For more information about each of these objects, see:

"TargetSet objects," page 1-6 "DrillingPlatform objects," page 1-6 "Planned well objects," page 1-7 "Sidetrack well objects" on page 1-8 "DrillingTemplates" on page 1-8

TargetSet objects In Well Planning, when you specify one or more target points (drilling targets) that you want a well path to reach, the result is a TargetSet object. Target sets should contain only the targets you want to reach with a single well, and therefore, usually contain only a small number of targets. You can create target sets from existing objects either automatically by extracting targets from the points in a PointsSet or a Curve object or manually by picking points on objects (such as voxets, surfaces, stratigraphic and 2D grids, and others) in the 3D Viewer (for example, see Figure 12 on page 1-6). You can also create targets by specifying coordinates for one target and a vector extension to create the second target.

Figure 12 TargetSetcreated by picking points

of high porosity on agrid region

After you create target sets, you will find them listed in the Objects browser in the Well category. For more information about creating TargetSets, see "Target" on page 1-15 and "Managing Targets" on page 3-2.

DrillingPlatformobjects

A platform in Well Planning is called a Drilling Platform object. When you plan a drilling platform, you select TargetSet objects as input, describe the platform geometry (for example, the number and arrangement of slots and the platform orientation), and specify any engineering criteria for the wells to be drilled from the platform. Well Planning automatically optimizes the assignment of targets to drilling slots (resulting in the DrillingPlatform object), and it proposes well paths to reach the specified targets.



After you create drilling platforms, you will find them listed in the Unassigned Objects browser in the DrillingPlatform object category and the associated wells in the Well category in the Objects browser. For information about the concepts Well Planning uses to propose drilling platforms and information about how to create them, see "Drilling Platforms" on page 1-16 and "Planning Drilling Platforms" on page 3-25.

Planned well objects When you plan wells, Well Planning creates Well objects that are similar to the SKUA and GOCAD wells with which you are probably already familiar (see Part IV: Foundation Modeling, "Creating and Editing Wells and Well Data" on page 9-1). Wells created with Well Planning contain all the data that SKUA and GOCAD wells have, but they also have extra information required for editing in Well Planning.

Caution If you save a project containing a planned well or save a planned well as an object file without having loaded the Basic Well Planning module, the well becomes a standard SKUA and GOCAD wellthat is, it will no longer contain the editing information required by Well Planning. You can use wells created with Well Planning in your projects just as you would use standard wells, regardless of whether you have loaded the module. However, if you want to ensure that you can edit a planned well later, you must not save the well or the project without having first loaded the Basic Well Planning module.

In the Objects browser, planned wells appear the same as standard wells because they both appear in the Well object category. However, you can easily distinguish planned wells from SKUA and GOCAD wells in the 3D Viewer because well paths created with Well Planning appear in green by default, whereas the default color for standard wells is red (see Figure 13). In addition, you can determine whether a well is a planned well from the Style dialog box for the well by reviewing the information in the History category.

For information about the concepts used to describe well paths and information about how to plan wells, see "Points on the Well Path" on page 1-12, and "Planning Wells" on page 3-14.

Figure 13 A plannedwell and SKUA andGOCAD well in the

3D Viewer

Note When you first create a planned well, the derrick does not appear on the well path in the 3D Viewer, but you can show it at any time by using the Style toolbar for the well.

SKUA and GOCAD well

Planned well created with Well Planning


Sidetrack well objects With the Side Track and Collision Risk module, you can plan a secondary well path that branches off of the main well path, called a sidetrack.

Figure 14 Sidetracksbranching from a parentwell, showing well path

uncertainty

When you plan sidetracks, Well Planning creates a Well object that is the same as a planned well (see "Planned well objects" on page 1-7). That is, sidetracks contain all the data that standard SKUA and GOCAD wells have plus the extra information required for editing. Like planned wells, sidetrack wells also appear in the Objects browser in the Well category and in green (the default color) when displayed in the 3D Viewer.

For more information about the concepts used to describe sidetrack well paths and information about how to create sidetracks, see "Sidetracks" on page 1-16 and "Planning Sidetracks" on page 3-32.

DrillingTemplates To plan wells and platforms with Well Planning, there are several parameters you can set up to specify the engineering criteria you want to use in your drilling plans. Well Planning stores this information in Drilling Parameter Templates for later use when you create each well or platform. To quickly get started, you can use the Well Planning default templates, or, by saving your own templates, you can specify customized parameters. Setting up the templates prevents you from having to enter the same information more than once.

You can use your templates in multiple Well Planning workflows or save the templates as object files for use in other projects.

For more information about the Drilling Parameter Templates, the parameters you can specify, and how to set them up in Well Planning, see "Setting Up Drilling Parameter Templates" on page 2-9.



1.3.3 Well Planning Shortcut MenusWith the Basic Well Planning module, when you right-click the Drilling Platform, Target Set, or Drilling Templates object category or a specific Well Planning object (Target Set, Drilling Platform, or Well) in the Objects browser, you access shortcut menus that contain frequently used commands specific to these objects.

You can access commands specific to a single object or commands for all of the objects of a specific type. The following describes how you access each shortcut menu.

For more information about Target Set, Well, Drilling Platform, and Drilling Template objects, see "Well Planning Objects" on page 1-6.

When you do this You can access this

Right-click the Drilling Platform category in the Objects browser

Commands for showing and hiding all drilling platforms in the 3D Viewer and accessing the styles for drilling platforms. You can also quickly create a platform from existing target sets.

For more information about DrillingPlatforms, see "Planning Drilling Platforms" on page 3-25.

Right-click the Target Set category in the Objects browser

Commands for showing and hiding all target sets in the 3D Viewer and accessing the styles for target sets. You can also quickly create a target set using any one of several methods.

For more information about TargetSets, see "Managing Targets" on page 3-2.

Right-click a Target Set, Well, or DrillingPlatform object in the Objects browser

Standard commands for copying, deleting, renaming, saving, and accessing the styles for the selected object. These commands work the same way for Well Planning objects as they do for other geometric objects.

For more information about these commands, see Part I: Getting Started, "Managing Objects" on page 3-1.

Note If you have also loaded the Side Track and Collision Risk module, when you right-click a well, you can also show or hide the uncertainty or collision risk for that well.

Right-click the Drilling Templates category or one of the subcategories, such as Well Drilling Parameters, in the Objects browser

Commands for creating templates, saving them to files for use in other projects, loading templates from saved files, and renaming or deleting custom Drilling Parameter Templates.

For more information about these commands, see "" on page 2-23.

Right-click a target set, well, or drilling platform in the 3D Viewer

Commands for accessing the Style toolbar for the object and for hiding or showing only the selected object.


1.3.4 Well Planning Editing ToolsWith the Basic Well Planning module, there are toolbars available for editing targets and wells. On the Digitization-Selection toolbar, you can select the object type and then the object you want to edit. When you do this, the Digitization/Editing toolbar changes to show editing tools specific to the selected object:

TargetSet.

The Digitization/Editing toolbar for TargetSet objects includes new commands for moving and deleting individual targets in target sets. These commands work the same way as the corresponding commands in Well Planningfor information, see "Editing Targets" on page 3-8.

Well.

The Digitization/Editing toolbar for planned wells includes three new commands (the last three tools on the right) for moving the location of the well head, moving the kickoff point along the well path, and reshaping the curvature of the path by moving the pull point. These commands work the same way as the corresponding commands in Well Planningfor information, see "Editing Wells" on page 3-18.

1.3.5 Well Planning Style ToolbarsWith the Basic Well Planning module, after you have created a target set, well, or drilling platform, you can adjust how these objects display in the 3D Viewer using the tools on the Style toolbar.

To access the graphic styles for a specific object, you can do any of the following:

Click the name of a Well Planning object in the Objects browser. Right-click a Well Planning object in the 3D Viewer, and then select Quick

Attributes.

Each method accesses the Style toolbar (at the bottom of the SKUA or GOCAD window) related to the selected object:

Note In Well Planning, when you select a well, platform, or target set from one of the panels in the workflow, another toolbar appears at the bottom of the SKUA or GOCAD window, the Well Planning Style toolbar, that provides access to the same commands you would find for the selected object on the Style toolbar.

TargetSet

The Style toolbar for target sets includes commands for displaying and changing the appearance of target sets in the 3D Viewer. For example, you can change the symbol that depicts the targets, change the color, show or hide numbers indicating the order of targets in the set, or show or hide lines connecting the targets.

Well

You can edit the graphic styles of planned wells the same way you would edit the styles of standard SKUA and GOCAD wells. With the Basic Well Planning module, the tools on the Style toolbar are the same for all wells, with one addition for planned wellsyou can



display the well editing points on the well path. With the Side Track and Collision Risk module, there are two additional commands for displaying computed uncertainty and collision risk along the well path.

DrillingPlatform

The Style toolbar for drilling platforms includes commands for displaying and changing the appearance of platforms in the 3D Viewer. For example, you can change the symbol that depicts the drilling slots, change the color, or show or hide numbers for the drilling slots.

1.3.6 Drilling Planner Category in the Style Dialog BoxWith the Basic Well Planning module, you can adjust how planned wells display in the 3D Viewer by using the commands in the Drilling Planner category in the Style dialog box.

To access these graphic styles for a planned well, you can right-click a well in the Objects browser or 3D Viewer, select Style > Editor to open the Style dialog box, and then select the Drilling Planner category.

Note You can display the uncertainty tube and collision risk if you have loaded the Side Track and Collision Risk module. For more information, see "What Is Side Track and Collision Risk?" on page 1-3.


1.4 Concepts in Well PlanningThis section provides an explanation of the terminology and concepts used in Well Planning to describe well paths and drilling platforms.

For more information, see:

"Points on the Well Path," page 1-12 "Sidetrack well objects" on page 1-8 "Drilling Platforms," page 1-16 "Well Path Uncertainty," page 1-20 "Collision Risk," page 1-20

1.4.1 Points on the Well PathThis section provides an explanation of the shape of the well curve and describes important points along the well path. It also explains terminology related to the engineering criteria that you can specify in Well Planning when planning a well.


"Tophole section," page 1-13 "KB," page 1-13 "Casing head flange," page 1-14 "Conductor inclination angle," page 1-14 "Nudge," page 1-14 "Kickoff," page 1-15 "Target," page 1-15 "Dogleg," page 1-15

Note For information about the object created when you plan a well, see "Planned well objects" on page 1-7.


1.4 Concepts in Well Planning 1-13User Guide

Tophole section The tophole section of a typical well path is illustrated in Figure 15.

Figure 15 Well planningparameters in the tophole

section of a well path

In the tophole section, the well path always maintains a constant azimuth (orientation measured in degrees from north). From the kelly bushing (KB) on the drill floor to the start nudge point, the well path comprises two straight sections, joined at the casing head flange on the wellhead deck.

The second section may be inclined at an angle, called the conductor inclination angle (), resulting in a kink between the sections. This section (sometimes called the prenudge section) continues until the depth is reached at which there is sufficient rock above the drill bit to allow directional drilling to beginthis is the start nudge point and the depth is the nudge depth.

The most significant part of the tophole is the nudge section. The effect of nudging is to apply a horizontal displacement to the well path at a constant azimuth. Nudging is used, for instance, on platforms with multiple wells to increase the distance between adjacent well paths, thus minimizing the risk of intersecting well paths.

From the start nudge point, the well path describes a curve of constant radius defined by the nudge rate (similar to dogleg severity) until it reaches the nudge inclination angle (). At this point, the intermediate nudge, the path usually describes an equal and opposite curve until the well path returns to vertical at the final nudge point.

The last section in the tophole is simply a vertical drop to the kickoff point. A slight variation on this design keeps the path straight after the intermediate nudge (the intermediate and final nudge points are coincident). In this case, the path does not revert to vertical; it remains inclined at the nudge angle until the kickoff depth is reached. Figure 16 on page 1-15 illustrates the difference in the two designs.

Beyond the kickoff, the well path is directed toward the drilling targets.

The following sections provide more information about the points introduced in this section.

KB The well path starts at the location of the kelly bushing (KB) point on the drill floor. The KB point is shown in Figure 15.

KB

Casing head flangeDatum

Nudge depth

Kic

koff

dep

th

Start nudge

Intermediate nudge

Final nudge

Kickoff

To targets

Nu

dge

sect

ion

= conductor inclination angle = nudge inclination angleDatum = sea level or reference depth


Casing head flange The casing head flange, located on the wellhead deck, is the point where the drill floor connects to the drillpipe below. A point representing the casing head flange is shown on the well path in Figure 15 on page 1-13.

Conductor inclinationangle

In Figure 15 on page 1-13, the path below the casing head flange is angled, indicating that the conductor pipe lining the top of the borehole is slanted rather than vertical. On a drilling platform with multiple wells, slanted conductors are sometimes used to avoid intersection with adjacent well paths. In the figure, the conductor inclination is the angle of the well path from the casing head flange to the start of the nudge. The position of each well on the drilling platform influences the conductor inclinationfor more information, see "Influence of platform geometry on well path" on page 1-17.

Nudge A slight curve in a well path prior to the kickoff point is called a nudge. The nudge section includes the path between the start and final nudge points (shown in Figure 15 on page 1-13). Nudging is a low-angle directional drilling technique that drilling engineers use to increase spacing between adjacent wells, thus minimizing the risk of intersecting well paths.

The following describes engineering criteria related to the nudge section of the well path.

Nudge depth. The nudge section starts at the depth of the first nudge point (start nudge), a depth at which there is sufficient rock above the drill bit to allow low-angle directional drilling to begin. If a well is to be drilled from a drilling platform, the platform geometry can influence the nudge depth as described in "Influence of platform geometry on well path" on page 1-17.

Nudge rate. The nudge rate is the curvature of the well path after the nudge (expressed as degrees per length). The nudge rate is similar to dogleg severity (see "Dogleg" on page 1-15).

Nudge inclination angle. As shown in Figure 15 on page 1-13, the nudge inclination is the angle of the well path at the intermediate nudge point. For a well on a drilling platform, platform geometry influences the nudge inclination. For more information, see"Influence of platform geometry on well path" on page 1-17.

Nudge azimuth. With Well Planning, you can design a well path that changes direction at the nudge depth. You specify the azimuth of the nudge in degrees measured clockwise from north using the 360-degree system (where 0 corresponds to north).

Revert to vertical after nudge. In Figure 15 on page 1-13, notice the vertical drop from the final nudge point to the kickoff. In Well Planning, you can design an alternative well path that does not revert to vertical. In this case, the path after the intermediate nudge is straight and inclined at the nudge angle until the kickoff depth is reached. For this design, the intermediate and final nudge points are coincident. See Figure 16 on page 1-15 for a comparison of the two designs.



Figure 16 Well pathvariation after the

nudgepath A revertsto vertical and path B

does not

Kickoff The kickoff point is the depth at which directional drilling toward one or more drilling targets begins. Figure 15 on page 1-13 illustrates the kickoff. The kickoff depth also marks the end of the tophole section of the well path. Above the kickoff, a well typically maintains a constant azimuth, whereas it may change direction at the kickoff.

Target A target is a location that you intend to reach when drilling a well path. A well path can reach more than one target. In Well Planning, well paths must pass through each of the targets specified for the well, and a well path always ends at a target. A collection of one or more target points for a particular well path is called a TargetSet object in Well Planning. For more information about TargetSet objects, see "TargetSet objects" on page 1-6.

Dogleg A dogleg is a curve in the well path. Dogleg severity (DLS) is the curvature of the well path expressed as degrees per length (usually, degrees/100 ft in the U.S. or degrees/30 m where metric units are used). With Well Planning, you can specify a preferred maximum dogleg severity for two doglegs, one at a shallow depth and another at a greater depth. For example, in Figure 17, the shallow DLS just below the kickoff is 3, while the deep DLS closer to the drilling targets is 10.

Figure 17 Preferredmaximum DLS for shallow

and deep doglegs

Start nudge

Intermediate nudge

Kickoff

Final nudge

Start nudge

Intermediate/final nudge

Kickoff

Targets Targets

A B

Vertical Nonvertical

Dogleg severity = 3 (preferred max.)

Kickoff

Dogleg severity = 10 (preferred max.)

Targets


1.4.2 SidetracksA sidetrack is a secondary well path that branches off of a parent well path. Sidetracks are usually planned to take advantage of the proximity of an area of interest to an existing well. Sidetracks are designed to reach either a single target horizontally or multiple targets. Both types of sidetracks are illustrated in Figure 18.

Figure 18 Sidetracks forsingle and multiple

targets

Notes

Sidetrack planning is available in Well Planning when you load the Side Track and Collision Risk module.

For information about the Well object created when you plan a sidetrack, see "Sidetrack well objects" on page 1-8.

1.4.3 Drilling PlatformsWell Planning is a powerful tool for planning platforms because it can automatically assign targets to drilling slots in addition to proposing the well paths to reach the selected targets. After you create a drilling platform, as with a stand-alone well, you can then edit the proposed well paths if necessary.

This section briefly describes the basic geometry of a drilling platform, the influence platform geometry can have on well paths, and how Well Planning allocates targets to drilling slots. It also explains terminology related to the engineering criteria that you can specify in Well Planning when planning a drilling platform.


"Platform geometry," page 1-17 "Influence of platform geometry on well path," page 1-17 "Slot-to-target allocation," page 1-19

Note For information about the DrillingPlatform object type, see "DrillingPlatform objects" on page 1-6.

Parent well path

Sidetrack to a single target

Sidetrack to two targets



Platform geometry A platform comprises a number of drilling slots organized in a symmetrical pattern. For example, Figure 19 illustrates a 24-slot platform arranged as four rows and six columns.

Figure 19 A 6x4 slotlayout on a platform

When you plan a platform in Well Planning, you must specify the orientation and size of the platform, including the number and arrangement of drilling slots on the platform. You do this by providing values for several parameters including the platform azimuth, the number of slots in the x and y directions, and the spacing between slots.

Platform azimuth (). The platform azimuth is the orientation of the y-axis of a platform (in degrees clockwise from north). You can specify a positive value for clockwise rotation or a negative value for counter-clockwise rotation.

X-slots. The x-slots are aligned along the x-axis (the long axis) of the platform, which is perpendicular to the orientation of the platform. In Well Planning, the number of x-slots must be greater than or equal to the number of y-slots.

Y-slots. The y-slots are aligned along the y-axis (the short axis), which is parallel to the orientation of the platform. In Well Planning, the number of y-slots must be less than or equal to the number of x-slots.

X-slot spacing. The distance between each slot along the x-axis.

Y-slot spacing. The distance between each slot along the y-axis.

Slot position. When Well Planning proposes the well paths for a platform, the slot position for a particular well influences the well path design. See "Influence of platform geometry on well path" on page 1-17.

Influence of platformgeometry on

well path

The challenge when planning a drilling platform is to increase spacing between adjacent well paths. The slot position of a particular well on the platform can influence the well path design. This section explains the influence of platform geometry specifically on the conductor inclination angle and the nudge depth and inclination angle.

This section provides information to help you understand the settings in Well Planning that are available when you plan a drilling platform, as described in:

"To edit the Platform Specifications template" on page 2-18 "To edit the Platform Drilling Parameters template" on page 2-20 "Planning Drilling Platforms" on page 3-25.

If any of the terms are unfamiliar to you, review the information presented in "Points on the Well Path" on page 1-12.

x

y

y-sl

ot s

paci

ng

x-slot spacing

inner slots

outer slots

N = Platform azimuth

Number of x-slots = 6

Number of y-slots = 4

x-slots y-slots


Conductor inclination (). One technique to increase well path separation is to vary the conductor inclination angle between wells in the inner and outer slots of the platform (see Figure 110). Using greater conductor inclinations for wells on the outer perimeter of the platform increases the separation between well paths in adjacent slots. In Well Planning, you can specify the range of conductor inclination angles between the inner slots (the Min. conductor inclination) and the outer slots (the Max. conductor inclination). Well Planning can then interpolate the angles for intermediate slots, if applicable, using the minimum and maximum values specified.

Figure 110 Increasingwell path separation

using conductorinclination angle

Nudge depth. Another spacing technique is to offset the nudges vertically for well paths in adjacent slots. To do this in Well Planning, you specify a minimum depth and a maximum depth. For example, if the minimum depth is 100 m, you could specify a maximum depth of 110 m. Given this scenario, alternate wells positioned on the outer perimeter would have nudge depths of 100 m and 110 m. If the drilling platform has a slot layout like the one shown in Figure 19 on page 1-17, Well Planning automatically interpolates the nudge offset for wells in intermediate slots.

Nudge inclination. From the nudge depth, a curved path is drilled until the angle of the path reaches the nudge inclination angle. Using a nudge inclination also increases the spacing between well paths by varying the angle between adjacent wells. Nudge inclination angles are greater for wells on the outer perimeter, which has the effect of ending the nudge section at a much shallower depth for wells in outer slots than for inner slots. To specify the range of nudge inclination angles between the inner and outer slots, in Well Planning, you specify a minimum inclination and nudge rate for the wells in the inner slots and a maximum inclination and nudge rate for wells in the outer slots. Well Planning can then interpolate the nudge inclination and nudge rates for intermediate wells, if applicable, using the minimum and maximum values specified.

The effect of the above adjustments is to increase the spacing between well paths from adjacent slots.

Figure 111 on page 1-19 is a simple illustration of these principles for a 3x2-slot platform.

2 3 3 2

intermediate slots

inner slots

Where is the conductor inclination angle1 > 2 > 31 = Max. conductor inclination3 = Min. conductor inclination

1

outer slots

1



Figure 111 A topholesection showing the

effect of platformgeometry on well paths

Note In Figure 111, also notice that the azimuth of each well path is spread out using regular angular spacing between adjacent slots. Well Planning does this automatically to further increase the distance between adjacent well paths.

Slot-to-targetallocation

Well Planning assigns targets to drilling slots automatically by performing a geometrical analysis of the target locations to determine the best slot-to-target configuration. The solution that Well Planning proposes reduces the risk of intersecting other well paths from the platform by performing an iterative process that includes:

Minimizing the distance between the slot and target. Reducing or eliminating well path crossover between the slot and target. Minimizing the difference between the azimuths in the tophole section and below the

kickoff.

For effective slot allocation, Well Planning also uses the concept of slot status. Each slot on a platform has one of these states:

Unlocked. Any free target can be drilled from an unlocked slot. Locked. A specific target is to be drilled from this slot (a well is already planned) or

the slot is reserved for later use.

Well Planning considers only unlocked slots for slot-to-target allocation. When Well Planning proposes a well path between a target and a slot (creating a Well object), that slot automatically changes to the locked state.

Note To unlock a slot, you can delete the associated well.

y

x

TVD


1.4.4 Well Path UncertaintyWith the Side Track and Collision Risk module, Well Planning can calculate and display uncertainty in the well path position. Accounting for positional uncertainty is important because it helps to identify areas of potential intersection with other well paths as explained in "Collision Risk" on page 1-20.

Well path uncertainty arises from the positional error along a well path introduced by the accuracy of measuring tools. Surveying instruments placed down the hole measure the azimuth, inclination, and measured (along hole) depth. These measurements determine how a well path is calculated.

Errors in the measurements cause a corresponding error in well path position, an error that accumulates with measured depth. A number of surveying tools can be used, all of which have their own characteristic strengths and weaknesses.

When you plan a well or platform in Well Planning, you specify the type of surveying tool. Based on the published error values for that type of tool, Well Planning computes potential positional error along the well path. You can then display the results as an uncertainty tube along the well path.

Figure 112 shows well path uncertainty tubes. Notice that uncertainty increases where the well path curves and at greater depth.

Figure 112 Well pathpositional uncertainty

displayed as tubes

For a list of the published error values for each type of tool you can select in Well Planning and more information about the uncertainty calculations, see "Published error values" on page A-4 and "Uncertainty Equations" on page A-3.

1.4.5 Collision RiskCollision risk is a feature of the Side Track and Collision Risk module related to uncertainty in the well path position (see "Well Path Uncertainty" on page 1-20). Knowing the distance between well paths is important when planning wells in regions where many wells already exist or when well paths are drilled from a drilling platform. Even more important is the ability to predict the distance between uncertainty tubes for planned wells because this represents the safest minimum distance that should be allowed between well paths.



With the Side Track and Collision Risk module, Well Planning can compute the distance between the well paths and show areas where a collision risk exists. Well Planning indicates collision risk in the 3D Viewer using tie lines between the paths as shown in Figure 113.

Figure 113 Collisionlines indicating where

well path proximity posesa collision risk

Well Planning automatically computes uncertainty and accounts for the distance between the uncertainty tubes in its collision risk calculations. See Figure 114.

Figure 114 Side view ofwells showing distance

between uncertaintytubes

Using knowledge of collision risk, you can adjust the paths of the planned wells as needed.

Uncertainty tubeUncertainty tube

Uncertaintyellipses

Distance

2-1

2Getting Started with Well Planning

In this chapter "Preparation for Well Planning," page 2-2

"Starting or Continuing a Well Planning Workflow," page 2-3

"Selecting Tasks in Well Planning," page 2-4

"Setting Up Drilling Parameter Templates," page 2-9

Overview These sections describe how to prepare for and start working in Well Planning and how to complete the first task, Drilling Parameter Templates.

Before you begin working in Well Planning, you need to gather the engineering criteria, objects, and data that you want to use in your drilling plan. For example, you may want to load or import any objects you have that represent the drilling area. You also need to determine whether you want to plan stand-alone wells, drilling platforms, or sidetrack wells (if you have the Side Track and Collision Risk module). Afterward, you can begin the guided workflow to create your drilling plan.

To start your drilling plan, you need to start the Well Planning Workflow, select the first task in Well Planning, and then set up the drilling parameters you want to use. Later, Well Planning will use these parameters to propose a drilling plan for each well or platform you want to create.

Getting Started with Well Planning2-2 SKUA and GOCAD Paradigm 2011With Epos 4.1 Data Management

2.1 Preparation for Well PlanningThe first step in well planning is to make sure you have the objects and data in your project that you want to use in the drilling plan. For example, you may have objects modeling the area you want to drill. Although this information is not required by Well Planning, you can incorporate geologic, geophysical, reservoir, and existing well data in your drilling plan.

To plan a well or drilling platform in Well Planning, you may find it helpful to have at least one object (such as a point set, curve, surface, stratigraphic grid, reservoir grid, or a voxet) that contains points or properties representing the target area you are interested in drilling. Later in the process, you can use this object to specify drilling targets by either extracting target points from the object (in the case of a curve or point set) or by picking points on the object in the 3D Viewer. For more information on specifying targets, see "Managing Targets" on page 3-2.

Once you have the objects you want to use in the project, you may find it useful to display them in the 3D Viewer before you start working in Well Planning.

Optional items that you may find helpful include:

Stratigraphic grids or a seismic volume containing properties of interest Existing wells, logs, and markers (if any) An object representing the lease boundary or area of interest Features defined for the objects in the project For offshore drilling:

An object representing sea level A horizon representing the depth and contour of the sea bed

Engineering criteria affecting the shape or location of the well bore (such as the dogleg base length used in the region, the orientation and size of an existing or planned drilling platform, or the kickoff depth you want to use)

Notes For more information, see:

"Concepts in Well Planning," page 1-12 Part I: Getting Started, "Loading an Object or Resource from an ASCII or XML Data File,"

page 3-17 Part I: Getting Started, "Importing Objects from Other Projects," page 3-10 Part II: Data Import and Export, "Importing Data," page 1-1 Part IV: Foundation Modeling, "Defining and Working with Geologic Features," page 8-1


2.2 Starting or Continuing a Well Planning Workflow 2-3User Guide

2.2 Starting or Continuing a Well Planning WorkflowTo start a drilling plan, you need to create a Well Planning workflow. Or, if you have already created one or more Well Planning workflows, you can select the workflow you want to continue working on.

For more information about workflows and how to create or select them and start working in Well Planning, see the following.

To access the WellPlanning workflow

On the Workflows tab, do one of the following:Tip If another workflow is open, click Open Scenarios and Workflows Browser (near the top of the workflow) to switch back to the Scenarios browser and Workflows browser.

The workflow opens.

Note For information about workflows, such as how to add them to a scenario, save, load, rename, or delete them, see Part I: Getting Started, "Managing Workflows and Scenarios" on page 6-9.

The first time you access the workflow, Well Planning displays the task selection panel. For information, see "Selecting Tasks in Well Planning" on page 2-4.

For information about another task, click Help at the bottom of the workflow to see the Help topics for that task.

If you want to Do this

Start a new workflow 1 In the Scenarios browser, select the scenario or the project (root scenario) to which to add the workflow.

2 In the Workflows browser, double-click the Well Planning icon.

The command adds the workflow to the selected scenario (or the project) and opens the workflow to the first task.

Continue work on a workflow that you already started

In the Scenarios browser, double-click the workflow that you want to open.

The command opens the workflow to the task where you worked last.


2.3 Selecting Tasks in Well PlanningAt the beginning and end of each task in Well Planning, the workflow displays the task selection panel (shown at the bottom of the workflow in Figure 21).

Figure 21 Task selectionin Well Planning

When you start the workflow, initially Drilling Parameter Templates is the only available task. The workflow selects it automatically on the task selection panel.

Tasks that appear dimmed (gray) are unavailable until you complete the prerequisites for the task. When you have completed a task, a check mark appears next to the task in the navigation pane at the top of the workflow. At any time while you are working in Well Planning, you can select tasks by clicking the name of the task in the navigation pane. Or, when presented with the task selection panel, you can start the next task in the sequence or select another available task.

Note The Sidetrack Planning task is available in Well Planning when you load the Side Track and Collision Risk module.

For information about each task and beginning the selected task or switching to another task, see:

"Tasks in Well Planning," page 2-5 "Well Planning workflow illustration," page 2-7 "Typical workflow for a drilling platform," page 2-8 "To select a task from the task selection panel," page 2-8 "To switch to another task from anywhere in the workflow," page 2-8

Task selection panel

Navigation pane


2.3 Selecting Tasks in Well Planning 2-5User Guide

Tasks in Well Planning The following provides a description of each of the tasks in Well Planning. For an illustration of the workflow, see Figure 22 on page 2-7.

Drilling Parameter Templates. Drilling Parameter Templates is a required task in which you set up the engineering criteria that you want to use in the drilling plan for each well path or platform you create with Well Planning. For example, you can enter the orientation of a drilling platform or the kickoff depth or dogleg base length you want to use. This task is a prerequisite for all of the remaining tasks. For more information see, "Setting Up Drilling Parameter Templates" on page 2-9.

When you finish setting up the parameters in the templates, the next task, Target Management, becomes available in the workflow.

Target Management. Target Management is a required task that includes two steps: Create Targets and Edit Targets. Creating targets is a prerequisite for all of the remaining tasks, regardless of the type of object you want to plan (well, platform, or sidetrack), whereas editing targets is optional. In the Create Targets step, you specify the drilling targets you want to reach during drilling. You can create a target set containing one or more target points to reach with a single well path or create several target sets that you want to reach from a drilling platform. For more information, see "Managing Targets" on page 3-2.

After you create targets, the Well Planning, Platform Planning, Sidetrack Planning (requires the Side Track and Collision Risk module), and Results tasks become available in the workflow. Each of these tasks are optional, and you can perform them in any order.

Well Planning. Well Planning is an optional task in which you can create stand-alone well paths to reach specific drilling targets. Well Planning uses the values you set in the Drilling Parameter Templates and the target sets you create during Target Management to plan the location and shape of well paths. For more information, see "Planning Wells" on page 3-14.

After you create a well, the Quality Control task becomes available in the workflow. This task is optional, and you can skip to it or perform any of the remaining tasks in any order.

Platform Planning. Platform Planning is an optional task in which you can create drilling platforms and well paths to reach specific drilling targets. Well Planning uses the values you set in the Drilling Parameter Templates and the target sets you create during Target Management to locate the platform, optimize the assignment of targets to drilling slots, and plan the shape of the associated well paths. For more information, see "Planning Drilling Platforms" on page 3-25.

After you create a platform, the Quality Control task becomes available in the workflow if it is not already available. You can skip to any task or perform the remaining tasks in order.

Sidetrack Planning. Sidetrack Planning is an optional task that is available with the Side Track and Collision Risk module. During this task, you can create sidetrack wells (well paths that branch off of a parent well) to reach one or more targets near an existing or planned well. Well Planning uses the values you set in the Drilling Parameter Templates and the target sets you create during Target Management to plan the shape of sidetrack wells. For more information, see "Planning Sidetracks" on page 3-32.

After you create a sidetrack, the Quality Control task becomes available in the workflow if it is not already available. You can skip to any task or perform the remaining tasks in order.

Quality Control. Quality Control is an optional task that you can perform at any time after you create a well, platform, or sidetrack with Well Planning. During this task, you can have Well Planning examine your well paths (stand-alone, platform, or sidetrack) and show you where the paths exceed a specified rate of curvature. You can extract


information from objects and properties along the well path of planned wells. In addition, if you have loaded the Side Track and Collision Risk module, you can display well path uncertainty and collision risk for each planned well. You can then use these properties and information to evaluate the quality of your drilling plan for each well path. For more information, see "Checking the Quality of Your Drilling Plans" on page 4-2.

After you perform the Quality Control task, you may want to refine your wells or platforms. For example, you might want to return to the Drilling Parameter Templates task to modify your drilling parameters or return to the editing steps in the Well, Platform, or Sidetrack Planning task to edit a well or platform individually.

Results. The Results task is an optional task that you can perform at any time after you complete the Create Targets step in Well Planning. During this task, you can review the results of your drilling plans, including the estimated costs and detailed information about the properties and well path trajectory of each Well Planning object you create. You can also export your drilling plans to an external file that you can then use in Microsoft Excel or any other program that can read HTML. For more information, see "Reviewing and Exporting the Results of Your Drilling Plans" on page 4-9.

When you have finished creating, editing, and reviewing the results of your drilling plans, you have completed the Well Planning workflow. You can return to it at any time to further refine your drilling plans or add well paths and platforms. You can also create additional Well Planning workflows and repeat the workflow process for the purpose of parallel comparison of drilling parameters. For more information, see "Starting or Continuing a Well Planning Workflow" on page 2-3.


2.3 Selecting Tasks in Well Planning 2-7User Guide

Well Planningworkflow illustration

Some of the tasks in Well Planning are required while others are optional depending on the type of objects you want to plan (stand-alone wells, drilling platforms, or sidetrack wells). You can also perform many of the tasks in any order. Figure 22 illustrates the Well Planning workflow.

For a detailed description of each task, see "Tasks in Well Planning" on page 2-5.

For an example of the order in which you might want to perform the tasks in Well Planning, see "Typical workflow for a drilling platform" on page 2-8.

Figure 22 Well Planningworkflow

Drilling Parameter Templates

What doyou want to

do?

Plan well or

sidetrack*

Plan drilling

platform

Target Management

Create Targets

Edit Targets

Well Planning

Create Wells

Set up these templates:

Platform Specifications

Platform Drilling Parameters

Cost Model

Collision Risk Cutoff*

Survey Model*

Set up these templates:

Well Drilling Parameters

Cost Model

Collision Risk Cutoff*

Survey Model*

Legend:

Required

Optional

*Items related to planning sidetrack wells and setting up and viewing uncertainty and collision risk are available with the Side Track and Collision Risk module.

After you complete a step, you can return to it at any time.

Start Drilling Planner

Platform Planning

Sidetrack Planning*

Edit Wells

Create Platforms

Edit Platforms

Create Sidetracks*

Edit Sidetracks*

Quality Control

Results


Typical workflow fora drilling platform

The following is an example of a typical workflow for planing a drilling platform:

1 Perform the required Drilling Parameter Templates and Target Management tasks to set up your engineering criteria and define drilling targets.

2 Skip to the Platform Planning task to create the platform and wells.

3 Skip to the Quality Control task to determine if you want to refine the drilling plans.

4 Return to the Edit Platforms step of Platform Planning to edit the drilling platform or return to the Edit Wells step of Well Planning to edit the associated well paths individually.

5 Return to the Quality Control task to confirm that your edits are satisfactory.

6 Continue to the Results task to review the costs associated with your drilling plans and export detailed reports of the planned objects.

To select a task fromthe task selection

panel

If you are just beginning a Well Planning workflow or you have just completed a task, the next available task is automatically selected on the task selection panel (see Figure 21 on page 2-4). To start the selected task or to choose another task, do the following:

1 Click the option button for one of the available tasks or leave the default selection.

Note For information about each task and information to help you determine which of the optional steps you need to complete, see "Tasks in Well Planning" on page 2-5 and "Well Planning workflow illustration" on page 2-7.

2 Click Next to continue.

Well Planning then displays the first panel for the selected task. For more information about the task, see:

"Setting Up Drilling Parameter Templates" on page 2-9 "Managing Targets" on page 3-2 "Planning Wells" on page 3-14 "Planning Drilling Platforms" on page 3-25 "Planning Sidetracks" on page 3-32 "Checking the Quality of Your Drilling Plans" on page 4-2 "Reviewing and Exporting the Results of Your Drilling Plans" on page 4-9

To switch to anothertask from anywhere

in the workflow

Click the task in the navigation pane at the top of the workflow. For information about each task, see "Tasks in Well Planning" on page 2-5.

Well Planning then displays the first panel for the selected task.

Tip Use this method when you want to return to a task from a later step in the workflow.


2.4 Setting Up Drilling Parameter Templates 2-9User Guide

2.4 Setting Up Drilling Parameter TemplatesWhen you start the workflow and access Well Planning, Drilling Parameter Templates is the first task you need to complete. For this task, you can use default engineering criteria or you can provide your own information about the wells you want to drill. For example, if you have specifications for a planned or existing drilling platform or you know the kickoff depth or dogleg base length you want to use to plan well paths, you can enter this information.

Later, Well Planning will incorporate the information you specify in the templates into the drilling plan for each well or platform you create. Thus, preventing you from having to enter the same information more than once.

Notes

After you create wells or platforms with Well Planning, you will have the opportunity to edit the parameters for a specific well or platform individuallyfor more information, see "Editing Wells" on page 3-18, "Editing Drilling Platforms" on page 3-30, and "Editing Sidetracks" on page 3-39.

If you want to use more than one set of drilling parameters to plan wells, you need to create more than one Well Planning workflow, one for each set of parameters you want to use.

When you start the Drilling Parameter Templates task, the workflow displays the list of templates you can edit (see Figure 23). These templates contain the engineering criteria that Well Planning will use in your drilling plans.

Figure 23 DrillingParameter Templates

panel in Well Planning

Note The Collision Risk Cutoff and Survey Model templates are available if you have loaded the Side Track and Collision Risk module.


For information about each template and how to complete the first task and manage templates, see:

"Templates in Well Planning," page 2-10 "Accepting the Default Drilling Parameters," page 2-11 "Editing Drilling Parameter Templates," page 2-12 "Validating, Resetting, and Initializing Drilling Parameters," page 2-22 "Completing the Drilling Parameter Templates Task," page 2-23

2.4.1 Templates in Well PlanningFor a description of the drilling parameter templates and a list of the templates related to each type of Well Planning object, see:

"Drilling parameter templates," page 2-10 "Determining which templates to set up," page 2-11

Drilling parametertemplates

Well Drilling Parameters. Set up parameters affecting the shape of the well path for stand-alone wells, such as the conductor angle, nudge, kickoff, and doglegs. You need to set up this template if you want to plan stand-alone wells or sidetrack wells. For information, see "To edit the Well Drilling Parameters template" on page 2-13.

Cost Model. Set up cost estimates to be used in the cost model computations for the well paths in your drilling plan. For example, the base drilling cost and deployment cost are used in cost model calculations for each proposed well. Well Planning automatically performs the cost model computations for all planned well paths (stand-alone, platform, or sidetrack), and, therefore, you should set up this template regardless of the type of object you want to plan. For information, see "To edit the Cost Model template" on page 2-15.

Survey Model. If you have loaded the Side Track and Collision Risk module, set up parameters affecting how Well Planning calculates uncertainty, such as the type of tool used to measure the position along the well path. With the Side Track and Collision Risk module, Well Planning automatically computes the uncertainty associated with all planned well paths, and therefore, you should set up this template regardless of the type of object you want to plan. For information, see "To edit the Survey Model template" on page 2-16.

Collision Risk Cutoff. If you have loaded the Side Track and Collision Risk module, set up parameters affecting how Well Planning quantifies collision risk, such as the distance between well paths considered critical or cautionary. With the Side Track and Collision Risk module, Well Planning automatically computes the collision risk associated with all planned well paths, and, therefore, you should set up this template regardless of the type of object you want to plan. For information, see "To edit the Collision Risk Cutoff template" on page 2-17.

Platform Specifications. Set up parameters affecting the geometry and orientation of a drilling platform, such as the elevation, orientation, or number of drilling slots. You need to set up this template if you want to plan a drilling platform. For information, see "To edit the Platform Specifications template" on page 2-18.

Platform Drilling Parameters. Set up parameters affecting the shape of the well paths drilled from a platform, such as the range of conductor angles, the nudge range, kickoff, and doglegs. You need to set up this template if you want to plan well paths to be drilled from a drilling platform. For information, see "To edit the Platform Drilling Parameters template" on page 2-20.



Determining whichtemplates to set up

The following provides information to help you determine which templates you need to set up, depending on the types of objects you want to plan.

Table 21 DrillingParameter Templates

related to eachDrilling Planner object

*Templates related to planning sidetrack wells and setting up and viewing uncertainty and collision risk are available with the Side Track and Collision Risk module.

2.4.2 Accepting the Default Drilling ParametersIf you have started the Drilling Parameter Templates task in Well Planning and you want to use the default values for all of the parameters in the drilling parameter templates, you can quickly validate the parameters and continue to the next task. You can always update the parameters with your own information later.

For information about how to accept the defaults, see the following procedure.

To accept the defaultdrilling parameters

On the Drilling Parameter Templates panel (see Figure 23 on page 2-9), click Validate .

The workflow saves the parameters in all of the templates at once, creating a DrillingTemplate object that contains all of the parameters for each type of template. Later, Well Planning will use these parameters in the drilling plan for each well or platform you create.

For more information about how Well Planning uses these parameters, see "Concepts in Well Planning" on page 1-12.

When you validate the drilling parameters, the next task, Target Management, becomes available. For information about how to continue to the next task, see "Completing the Drilling Parameter Templates Task" on page 2-23.

To plan this object Set up these templates

Stand-alone well Well Drilling ParametersCost ModelSurvey Model*Collision Risk Cutoff*

Drilling platform Platform Drilling ParametersPlatform SpecificationsCost ModelSurvey Model*Collision Risk Cutoff*

Sidetrack well* Well Drilling ParametersCost ModelSurvey Model*Collision Risk Cutoff*


2.4.3 Editing Drilling Parameter TemplatesWhen you start the Drilling Parameter Templates task, the workflow displays the list of templates you can edit (see Figure 24). These templates contain the engineering criteria that Well Planning will use in the drilling plan for each well or platform you create.

Figure 24 DrillingParameter Templates

panel in Well Planning

Note The Collision Risk Cutoff and Survey Model templates are available with the Side Track and Collision Risk module.

You do not have to enter values for every parameter or even every template, only for the ones you want to change or only those that apply to your drilling plan. For example, if you are not planning a drilling platform, you do not need to edit the Platform Specifications or Platform Drilling Parameters templates. For more information about each template, see "Drilling parameter templates" on page 2-10 and "Determining which templates to set up" on page 2-11.

Note If you want to use more than one set of drilling parameters to plan wells or platforms, you can do this by creating one Well Planning Workflow for each set of parameters.

For information about how to edit the drilling parameters, see:

"To edit the Well Drilling Parameters template," page 2-13 "To edit the Cost Model template," page 2-15 "To edit the Survey Model template," page 2-16 "To edit the Collision Risk Cutoff template," page 2-17 "To edit the Platform Specifications template," page 2-18 "To edit the Platform Drilling Parameters template," page 2-20



To edit the WellDrilling Parameters

template

If you want to edit the parameters affecting the shape of the well path for stand-alone wells, such as the conductor, nudge, kickoff, and doglegs, do the following:

1 On the Drilling Parameter Templates panel, under Templates, click the Well Drilling Parameters template.

The parameters you can specify appear on the right side of the panel.

Using a conductor angle and applying a nudge (a slight curve) in the tophole section of the well path are techniques used to increase spacing between adjacent wells. Below the kickoff, the well path may curve to reach the drilling targets. These curves are called doglegs.

Note For more information and illustrations of these parameters, see "Points on the Well Path" on page 1-12.

2 Edit any of the following by typing a new value in the box or selecting an option from the list next to the parameter:

Under Conductor: Inclination. Specifies the angle of inclination of the well path between the casing head flange and the start of the nudge (nudge depth). The angle is measured in degrees from vertical (where vertical is 0 degrees). Valid values include 090.

Under Nudge:

Tip To check the units set for the project, on the File menu, click Project Properties.

Depth. Specifies the true vertical depth subsea (TVDSS) of the start of the nudge in either +/- feet or meters, depending on the units and direction of positive depth values set for the project.


Rate. Specifies the curvature of the well path after the nudge in degrees per length. The nudge rate is measured over the same length that doglegs are measured (see Dogleg base length)therefore, the unit is either feet or meters, depending on the unit set for doglegs.

Azimuth. Specifies the direction of the well path at the nudge depth in degrees measured clockwise from north (where north is 0 degrees). Valid values include 0360.

Inclination. Specifies the angle of inclination of the well path at the intermediate nudge point. The nudge angle is measured in degrees from vertical (where vertical is 0 degrees). Valid values include 090.

Revert to vertical. Specifies whether the well path is vertical (true) between the final nudge point and the kickoff or inclined (false) at the angle between the intermediate nudge point and the kickoff.

Under Kickoff:

Depth. Specifies the true vertical depth subsea (TVDSS) at which directional drilling begins to reach one or more drilling targets. This depth marks the end of the tophole section and must be below the nudge depth. The unit of length is either +/- feet or meters, depending on the units and the direction of positive depth values set for the project.

Azimuth. Specifies the direction of the well path at the kickoff depth in degrees measured clockwise from north (where north is 0 degrees). Valid values include 0360.

Under Dogleg:

Dogleg base length. The left box specifies the length over which doglegs (curves in the well path) are measured in the region and the right box specifies unit (typically, 100 ft in the U.S., 10 m in Norway, or 30 m elsewhere).

Caution The nudge rate and dogleg severity for both stand-alone wells and well drilled from platforms require the length you specify as the dogleg base length. Thus, when you change this length or the unit, the rate and units of the nudge rate and dogleg severity parameters in this template and in the Platform Drilling Parameters template also change. In addition, the change may affect the nudge rate and dogleg severities you need to specify.

Shallow hole dogleg severity. Specifies the curvature of the well path for a dogleg just below the kickoff point in degrees per length. The unit of length is that specified for the Dogleg base length.

Deep hole dogleg severity. Specifies the curvature of the well path for a downhole dogleg (that is, a curve close to the drilling targets) in degrees per length. The unit of length is that specified for the Dogleg base length.

Depending on the type of rock and conditions, the dogleg severity of the deeper dogleg is often twice that of the shallow dogleg.

Under Measured depth: Unit. Specifies the unit you want to use to define the length measured along the well path (m or ft).

3 If you want to edit another template, click the name of the template, and then enter new values for the parameters you want to change.



When you have finished editing the drilling parameters, you need to validate your changes before you can complete this task. You can also reset your last changes, re-initialize the default drilling parameters, or initialize parameters from an existing DrillingTemplate. For information, see:

"Validating, Resetting, and Initializing Drilling Parameters" on page 2-22. "Completing the Drilling Parameter Templates Task" on page 2-23

To edit the CostModel template

If you want to provide your own cost estimates to be used in the cost model for the wells in your drilling plan, do the following:

1 On the Drilling Parameter Templates panel, under Templates, click the Cost Model template.


Costs such as the base drilling cost and deployment cost will be used in the cost model computations for each planned well. For more information about how Well Planning uses these costs, see "Cost Model Equation" on page A-2.

Note The Base milling and Milling factor costs appear on the panel if you have loaded the Side Track and Collision Risk module.

2 Edit any of the following by typing a new value in the box next to the parameter:

Base. Specifies the cost of drilling per foot or cost per meter ($/ft or $/m), depending on the units set for the project.

Note The rest of the costs you can specify are not included in the Base cost.

Inclination. Specifies the cost of drilling per degree of inclination of the well path ($/degree).

Dogleg. Specifies the cost of drilling per dogleg severity ($/degree/ft or $/degree/m, depending on the unit set for the Dogleg base length in the Well Drilling Parameters template).

Deployment. Specifies the cost to run the tool downhole and record logs, including rig time ($/log run).


Base milling. Specifies the cost to drill through the casing to add a sidetrack ($/perforation).

Milling factor. Specifies the cost to drill through the casing per casing diameter ($/in.).


When you have finished editing the drilling parameters, you need to validate your changes before you can complete this task. You can also reset your last changes, reinitialize the default drilling parameters, or initialize parameters from an existing DrillingTemplate. For information, see:

"Validating, Resetting, and Initializing Drilling Parameters" on page 2-22. "Completing the Drilling Parameter Templates Task" on page 2-23

To edit the SurveyModel template

If you have loaded the Side Track and Collision Risk module and you want to edit the parameters affecting how Well Planning calculates uncertainty, such as the type of tool used to measure along the well path, do the following:

1 On the Drilling Parameter Templates panel, under Templates, click the Survey Model template.


The survey tool you select influences how Well Planning calculates the size and shape of the uncertainty cone for each well path. For example, the uncertainty calculations take into account the published values for relative depth error, misalignment error, true inclination error, reference error, drillstring magnetization error, and gyrocompass error for the specific tool you select. For a list of the error values Well Planning uses, see "Published error values" on page A-4.

Note For more information about well path uncertainty, see "Well Path Uncertainty" on page 1-20 and "Uncertainty Equations" on page A-3.

2 Edit any of the following by selecting a new value from the list next to the parameter:

Survey tool. Specifies the type of tool used to measure the uncertainty in well path position along the borehole (for example, measurement while drilling [MWD], inertial, magnetic, gyroscopic, or none).

Uncertainty unit. Specifies the unit used to calculate well path positional uncertainty (ft or m). The default unit matches that set for the project.




When you have finished editing the drilling parameters, you need to validate your changes before you can complete this task. You can also reset y

Well Planning

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