Class10-11upg2014
description
Transcript of Class10-11upg2014
![Page 1: Class10-11upg2014](https://reader034.fdocuments.in/reader034/viewer/2022042821/55cf91a6550346f57b8f454a/html5/thumbnails/1.jpg)
WS UPG 2013 -2014
Ingineria exploatarii optimale a utilajului petrolier
By Dr. C. Teodoriu
![Page 2: Class10-11upg2014](https://reader034.fdocuments.in/reader034/viewer/2022042821/55cf91a6550346f57b8f454a/html5/thumbnails/2.jpg)
UPG 2014, Dr. Dr. –Ing. habil. Catalin Teodoriu
Ingineria exploatarii optimale a utilajului petrolier
Drilling Concepts, Drilling Optimization
By Dr. C. Teodoriu
![Page 3: Class10-11upg2014](https://reader034.fdocuments.in/reader034/viewer/2022042821/55cf91a6550346f57b8f454a/html5/thumbnails/3.jpg)
UPG 2014, Dr. Dr. –Ing. habil. Catalin Teodoriu
Outcomes
At the end of this lecture, you will be able to;
- Understand the costs involved in drilling operation
- Understand the meaning of RISK in drilling and fishing
- Calculate when to quit fishing operations, calculate the cost per foot
![Page 4: Class10-11upg2014](https://reader034.fdocuments.in/reader034/viewer/2022042821/55cf91a6550346f57b8f454a/html5/thumbnails/4.jpg)
UPG 2014, Dr. Dr. –Ing. habil. Catalin Teodoriu
Well Integrity Concept
Well Planning
Virtual
Well
Simulations
Well
Construction
Quality
assurance
Re-
evaluation
Well Exploitation
Well
monitoring Repair
![Page 5: Class10-11upg2014](https://reader034.fdocuments.in/reader034/viewer/2022042821/55cf91a6550346f57b8f454a/html5/thumbnails/5.jpg)
UPG 2014, Dr. Dr. –Ing. habil. Catalin Teodoriu
Well Components
Casing-cement system
Well head complex
Production tubing
and completion
![Page 6: Class10-11upg2014](https://reader034.fdocuments.in/reader034/viewer/2022042821/55cf91a6550346f57b8f454a/html5/thumbnails/6.jpg)
UPG 2014, Dr. Dr. –Ing. habil. Catalin Teodoriu
Barrier Terminology, D-010 Well Integrity in Drilling and Well Operations, Presentation from 07.09.2004
Working Well Barrier Stage:
This is the stage which shows the well barrier elements that
are used to confine the pressure in a normal working mode.
Example: Closed CT strippers + CT body + surface test tree w. closed wing valve, +++
Intermediate Well Barrier Stage:
This is the stage(s) of a well barrier element activation
sequence before the ultimate well barrier stage is reached.
Examples: Leak in CT strippers – close CT pipe rams.
Ultimate Well Barrier Stage:
This is the final stage of a well barrier element activation sequence which normally
includes closing a shearing
device. Example: Closed CT shear ram (primary
barrier) or closed master valve (secondary barrier),+++
Primary Well Barrier:
This is first object that prevents flow from a source.
Example - blue items: Strippers + CT BOP+ surface test tree,+++
Common Well Barrier Element:
This is a barrier element that is shared between primary and
secondary barrier. Examples: Body of LRP, X.mas tree and
production wing valve
Well Barrier Element: An object that alone can not prevent flow from one side to
the other side of itself. Example: CT BOP
Secondary Well Barrier: This is the second object that prevents flow from a source.
Example - red items: Lower riser package + production tree + wellhead,+++
![Page 7: Class10-11upg2014](https://reader034.fdocuments.in/reader034/viewer/2022042821/55cf91a6550346f57b8f454a/html5/thumbnails/7.jpg)
UPG 2014, Dr. Dr. –Ing. habil. Catalin Teodoriu
4) NOTE:
Legend:
1. This describes the name of the well barrier elements.
2. A complete description of general acceptance criteria for this barrier element is found in
Clause 15, which contains a library of Well Barrier Element Acceptance Criteria tables.
3. This table column is used to describe comments.
4. The place can be used for describing additional requirements and guidelines. For example a
description of compensative measures if there exist common barrier elements.
5. The illustration shows the primary barrier in its normal working stage, while the secondary
barrier is shown in its ultimate stage. This stage often described with a closed shearing device.
5.
Well
Barr
ier
Sch
em
ati
cs
1) Well barrier elements
See Table
2)
3) Comments
Primary well barrier
1. Fluid column 1
Secondary wellbarrier
1. Casing cement 22
2. Casing 2 Last casing set
3. Wellhead 5
4. High pressure riser 26 If installed
5. Drilling BOP 4
![Page 8: Class10-11upg2014](https://reader034.fdocuments.in/reader034/viewer/2022042821/55cf91a6550346f57b8f454a/html5/thumbnails/8.jpg)
UPG 2014, Dr. Dr. –Ing. habil. Catalin Teodoriu
Risk Assessment of Drilling Projects
1. Introduction
2. Definition
- Kind of Risks
- Development of Risk Assessment
- Methods of Risk Assessment
3. General Conditions of Risk Assessment
External Conditions
Internal Conditions
4. Example
Risk Assessment to compare different Projects
Risk Assessment for a certain Drilling Project
![Page 9: Class10-11upg2014](https://reader034.fdocuments.in/reader034/viewer/2022042821/55cf91a6550346f57b8f454a/html5/thumbnails/9.jpg)
UPG 2014, Dr. Dr. –Ing. habil. Catalin Teodoriu
![Page 10: Class10-11upg2014](https://reader034.fdocuments.in/reader034/viewer/2022042821/55cf91a6550346f57b8f454a/html5/thumbnails/10.jpg)
UPG 2014, Dr. Dr. –Ing. habil. Catalin Teodoriu
![Page 11: Class10-11upg2014](https://reader034.fdocuments.in/reader034/viewer/2022042821/55cf91a6550346f57b8f454a/html5/thumbnails/11.jpg)
UPG 2014, Dr. Dr. –Ing. habil. Catalin Teodoriu
What is a Risk?
![Page 12: Class10-11upg2014](https://reader034.fdocuments.in/reader034/viewer/2022042821/55cf91a6550346f57b8f454a/html5/thumbnails/12.jpg)
UPG 2014, Dr. Dr. –Ing. habil. Catalin Teodoriu
Risk Workshop Frequency Assessment Guidelines
![Page 13: Class10-11upg2014](https://reader034.fdocuments.in/reader034/viewer/2022042821/55cf91a6550346f57b8f454a/html5/thumbnails/13.jpg)
UPG 2014, Dr. Dr. –Ing. habil. Catalin Teodoriu
Chances and Dangers
![Page 14: Class10-11upg2014](https://reader034.fdocuments.in/reader034/viewer/2022042821/55cf91a6550346f57b8f454a/html5/thumbnails/14.jpg)
UPG 2014, Dr. Dr. –Ing. habil. Catalin Teodoriu
Kind of Risks
Geological Risks
Technical Risks
HSE Risks
(Health, Safety & Environment)
Financial Risks
Human lives!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
![Page 15: Class10-11upg2014](https://reader034.fdocuments.in/reader034/viewer/2022042821/55cf91a6550346f57b8f454a/html5/thumbnails/15.jpg)
UPG 2014, Dr. Dr. –Ing. habil. Catalin Teodoriu
Development of Risk Assessment
Deterministic Analysis Stochastic Analysis
Risk Assessment
![Page 16: Class10-11upg2014](https://reader034.fdocuments.in/reader034/viewer/2022042821/55cf91a6550346f57b8f454a/html5/thumbnails/16.jpg)
UPG 2014, Dr. Dr. –Ing. habil. Catalin Teodoriu
![Page 17: Class10-11upg2014](https://reader034.fdocuments.in/reader034/viewer/2022042821/55cf91a6550346f57b8f454a/html5/thumbnails/17.jpg)
UPG 2014, Dr. Dr. –Ing. habil. Catalin Teodoriu
Decision –Tree
![Page 18: Class10-11upg2014](https://reader034.fdocuments.in/reader034/viewer/2022042821/55cf91a6550346f57b8f454a/html5/thumbnails/18.jpg)
UPG 2014, Dr. Dr. –Ing. habil. Catalin Teodoriu
Spider Diagram for a Diesel Powered Vehicle
![Page 19: Class10-11upg2014](https://reader034.fdocuments.in/reader034/viewer/2022042821/55cf91a6550346f57b8f454a/html5/thumbnails/19.jpg)
UPG 2014, Dr. Dr. –Ing. habil. Catalin Teodoriu
General Conditions of Risk Assessments
External
Conditions:
Governmental Regulation
Non – Governmental
Relations
Internal
Conditions:
Economical Forces
![Page 20: Class10-11upg2014](https://reader034.fdocuments.in/reader034/viewer/2022042821/55cf91a6550346f57b8f454a/html5/thumbnails/20.jpg)
UPG 2014, Dr. Dr. –Ing. habil. Catalin Teodoriu
Trend lost in Time incident Frequency (LTIF) per region
![Page 21: Class10-11upg2014](https://reader034.fdocuments.in/reader034/viewer/2022042821/55cf91a6550346f57b8f454a/html5/thumbnails/21.jpg)
UPG 2014, Dr. Dr. –Ing. habil. Catalin Teodoriu
How to Tackle Corporate Problems?
![Page 22: Class10-11upg2014](https://reader034.fdocuments.in/reader034/viewer/2022042821/55cf91a6550346f57b8f454a/html5/thumbnails/22.jpg)
UPG 2014, Dr. Dr. –Ing. habil. Catalin Teodoriu
The Two Questions:
Is the project viable?
Which options of the chosen
project is the favourable?
![Page 23: Class10-11upg2014](https://reader034.fdocuments.in/reader034/viewer/2022042821/55cf91a6550346f57b8f454a/html5/thumbnails/23.jpg)
UPG 2014, Dr. Dr. –Ing. habil. Catalin Teodoriu
Price Sensitivity of three Example Projects
![Page 24: Class10-11upg2014](https://reader034.fdocuments.in/reader034/viewer/2022042821/55cf91a6550346f57b8f454a/html5/thumbnails/24.jpg)
UPG 2014, Dr. Dr. –Ing. habil. Catalin Teodoriu
Scenario Analysis of three Example Projects
![Page 25: Class10-11upg2014](https://reader034.fdocuments.in/reader034/viewer/2022042821/55cf91a6550346f57b8f454a/html5/thumbnails/25.jpg)
UPG 2014, Dr. Dr. –Ing. habil. Catalin Teodoriu
Example Well Design Options
![Page 26: Class10-11upg2014](https://reader034.fdocuments.in/reader034/viewer/2022042821/55cf91a6550346f57b8f454a/html5/thumbnails/26.jpg)
UPG 2014, Dr. Dr. –Ing. habil. Catalin Teodoriu
Casing Option 1
![Page 27: Class10-11upg2014](https://reader034.fdocuments.in/reader034/viewer/2022042821/55cf91a6550346f57b8f454a/html5/thumbnails/27.jpg)
UPG 2014, Dr. Dr. –Ing. habil. Catalin Teodoriu
Casing Option 2
![Page 28: Class10-11upg2014](https://reader034.fdocuments.in/reader034/viewer/2022042821/55cf91a6550346f57b8f454a/html5/thumbnails/28.jpg)
UPG 2014, Dr. Dr. –Ing. habil. Catalin Teodoriu
Comparison of three Casing Options
![Page 29: Class10-11upg2014](https://reader034.fdocuments.in/reader034/viewer/2022042821/55cf91a6550346f57b8f454a/html5/thumbnails/29.jpg)
UPG 2014, Dr. Dr. –Ing. habil. Catalin Teodoriu
Decison Tree – Definition
A decision tree maps out the result of different decisions which can be
made.
It helps to select the best way to proceed in a situation when the
outcomes are uncertain.
It uses values and probabilities to calculate
Effective Monetary Value
![Page 30: Class10-11upg2014](https://reader034.fdocuments.in/reader034/viewer/2022042821/55cf91a6550346f57b8f454a/html5/thumbnails/30.jpg)
UPG 2014, Dr. Dr. –Ing. habil. Catalin Teodoriu
Decision Tree 1
![Page 31: Class10-11upg2014](https://reader034.fdocuments.in/reader034/viewer/2022042821/55cf91a6550346f57b8f454a/html5/thumbnails/31.jpg)
UPG 2014, Dr. Dr. –Ing. habil. Catalin Teodoriu
Decision Tree: Exercise New Game
Now instead of either winning or not losing money you have a different
game: win $ 100 or lose $ 110
Would you play this game?
![Page 32: Class10-11upg2014](https://reader034.fdocuments.in/reader034/viewer/2022042821/55cf91a6550346f57b8f454a/html5/thumbnails/32.jpg)
UPG 2014, Dr. Dr. –Ing. habil. Catalin Teodoriu
Decision Tree: Answer
EMV = (0.56 x 100) + (0.44 x (- )) =
I Would!
![Page 33: Class10-11upg2014](https://reader034.fdocuments.in/reader034/viewer/2022042821/55cf91a6550346f57b8f454a/html5/thumbnails/33.jpg)
UPG 2014, Dr. Dr. –Ing. habil. Catalin Teodoriu
Decision Tree 2
![Page 34: Class10-11upg2014](https://reader034.fdocuments.in/reader034/viewer/2022042821/55cf91a6550346f57b8f454a/html5/thumbnails/34.jpg)
UPG 2014, Dr. Dr. –Ing. habil. Catalin Teodoriu
Fishing Decision Tree
A decision tree is used to evaluate the Effective Monetary Value (EMV) of
different courses of action.
![Page 35: Class10-11upg2014](https://reader034.fdocuments.in/reader034/viewer/2022042821/55cf91a6550346f57b8f454a/html5/thumbnails/35.jpg)
UPG 2014, Dr. Dr. –Ing. habil. Catalin Teodoriu
Decision Tree if Fail on the First Day
![Page 36: Class10-11upg2014](https://reader034.fdocuments.in/reader034/viewer/2022042821/55cf91a6550346f57b8f454a/html5/thumbnails/36.jpg)
UPG 2014, Dr. Dr. –Ing. habil. Catalin Teodoriu
Decision Tree if Fail on the First Day
![Page 37: Class10-11upg2014](https://reader034.fdocuments.in/reader034/viewer/2022042821/55cf91a6550346f57b8f454a/html5/thumbnails/37.jpg)
UPG 2014, Dr. Dr. –Ing. habil. Catalin Teodoriu
Some Rules of Thumb
Fishing economics become secondary when radiactive sources are in the
fish.
![Page 38: Class10-11upg2014](https://reader034.fdocuments.in/reader034/viewer/2022042821/55cf91a6550346f57b8f454a/html5/thumbnails/38.jpg)
UPG 2014, Dr. Dr. –Ing. habil. Catalin Teodoriu
Project Time Breakdown – Texas
![Page 39: Class10-11upg2014](https://reader034.fdocuments.in/reader034/viewer/2022042821/55cf91a6550346f57b8f454a/html5/thumbnails/39.jpg)
UPG 2014, Dr. Dr. –Ing. habil. Catalin Teodoriu
Project Time Breakdown – Senegal
![Page 40: Class10-11upg2014](https://reader034.fdocuments.in/reader034/viewer/2022042821/55cf91a6550346f57b8f454a/html5/thumbnails/40.jpg)
UPG 2014, Dr. Dr. –Ing. habil. Catalin Teodoriu
Project Cost Breakdown – Texas
![Page 41: Class10-11upg2014](https://reader034.fdocuments.in/reader034/viewer/2022042821/55cf91a6550346f57b8f454a/html5/thumbnails/41.jpg)
UPG 2014, Dr. Dr. –Ing. habil. Catalin Teodoriu
Project Cost Breakdown – Texas
![Page 42: Class10-11upg2014](https://reader034.fdocuments.in/reader034/viewer/2022042821/55cf91a6550346f57b8f454a/html5/thumbnails/42.jpg)
UPG 2014, Dr. Dr. –Ing. habil. Catalin Teodoriu
Drilling Concept – think different!!!
![Page 43: Class10-11upg2014](https://reader034.fdocuments.in/reader034/viewer/2022042821/55cf91a6550346f57b8f454a/html5/thumbnails/43.jpg)
UPG 2014, Dr. Dr. –Ing. habil. Catalin Teodoriu
Drilling Optimization Using Different Drilling Concepts
![Page 44: Class10-11upg2014](https://reader034.fdocuments.in/reader034/viewer/2022042821/55cf91a6550346f57b8f454a/html5/thumbnails/44.jpg)
UPG 2014, Dr. Dr. –Ing. habil. Catalin Teodoriu
Drilling Optimization
![Page 45: Class10-11upg2014](https://reader034.fdocuments.in/reader034/viewer/2022042821/55cf91a6550346f57b8f454a/html5/thumbnails/45.jpg)
UPG 2014, Dr. Dr. –Ing. habil. Catalin Teodoriu
ROP
Optimization
![Page 46: Class10-11upg2014](https://reader034.fdocuments.in/reader034/viewer/2022042821/55cf91a6550346f57b8f454a/html5/thumbnails/46.jpg)
UPG 2014, Dr. Dr. –Ing. habil. Catalin Teodoriu
How to Improve Bit Life – Optimized BHA Design
![Page 47: Class10-11upg2014](https://reader034.fdocuments.in/reader034/viewer/2022042821/55cf91a6550346f57b8f454a/html5/thumbnails/47.jpg)
UPG 2014, Dr. Dr. –Ing. habil. Catalin Teodoriu
Central Jet System
Standard Diverting Mini Extended
Jet Nozzles Optimization
![Page 48: Class10-11upg2014](https://reader034.fdocuments.in/reader034/viewer/2022042821/55cf91a6550346f57b8f454a/html5/thumbnails/48.jpg)
UPG 2014, Dr. Dr. –Ing. habil. Catalin Teodoriu
Drill Bit Optimization
Recommended rotary speed for core bits (Courtesy Hughes Christensen)
![Page 49: Class10-11upg2014](https://reader034.fdocuments.in/reader034/viewer/2022042821/55cf91a6550346f57b8f454a/html5/thumbnails/49.jpg)
UPG 2014, Dr. Dr. –Ing. habil. Catalin Teodoriu
Drill Bit Optimization
Bit weight for core bits (Courtesy Hughes Christensen)
![Page 50: Class10-11upg2014](https://reader034.fdocuments.in/reader034/viewer/2022042821/55cf91a6550346f57b8f454a/html5/thumbnails/50.jpg)
UPG 2014, Dr. Dr. –Ing. habil. Catalin Teodoriu
Drill Bit Specifications
Critical rotary speed for core bits
(Courtesy Hughes Christensen)
![Page 51: Class10-11upg2014](https://reader034.fdocuments.in/reader034/viewer/2022042821/55cf91a6550346f57b8f454a/html5/thumbnails/51.jpg)
UPG 2014, Dr. Dr. –Ing. habil. Catalin Teodoriu
Feet per Day vs. Effective ROP, SPE 50557
![Page 52: Class10-11upg2014](https://reader034.fdocuments.in/reader034/viewer/2022042821/55cf91a6550346f57b8f454a/html5/thumbnails/52.jpg)
UPG 2014, Dr. Dr. –Ing. habil. Catalin Teodoriu
Interval length vs. Bits per Interval, SPE 50557
![Page 53: Class10-11upg2014](https://reader034.fdocuments.in/reader034/viewer/2022042821/55cf91a6550346f57b8f454a/html5/thumbnails/53.jpg)
UPG 2014, Dr. Dr. –Ing. habil. Catalin Teodoriu
Drill Path Optimization
Plan view of application B shows the comparison between
optimized GA design and conventional design
![Page 54: Class10-11upg2014](https://reader034.fdocuments.in/reader034/viewer/2022042821/55cf91a6550346f57b8f454a/html5/thumbnails/54.jpg)
UPG 2014, Dr. Dr. –Ing. habil. Catalin Teodoriu
Source: Bit Optimization for the Shetland in Hydro’s
Oseberg south Field, SPE Bergen, April 2004
![Page 55: Class10-11upg2014](https://reader034.fdocuments.in/reader034/viewer/2022042821/55cf91a6550346f57b8f454a/html5/thumbnails/55.jpg)
UPG 2014, Dr. Dr. –Ing. habil. Catalin Teodoriu
Increase exponentially with depth.
Thus, when curve-fitting drilling cost data, it is often to assume a
relationship between total well cost, C, and depth, D, given by:
Drilling Costs
![Page 56: Class10-11upg2014](https://reader034.fdocuments.in/reader034/viewer/2022042821/55cf91a6550346f57b8f454a/html5/thumbnails/56.jpg)
UPG 2014, Dr. Dr. –Ing. habil. Catalin Teodoriu
When major variations are not present in the subsurface lithology, the
penetration rate usually decreases exponentially with depth. Under these
conditions, the penetration rate can be related to depth, D, by:
Where K and a2 are constants.
Penetration Rate
![Page 57: Class10-11upg2014](https://reader034.fdocuments.in/reader034/viewer/2022042821/55cf91a6550346f57b8f454a/html5/thumbnails/57.jpg)
UPG 2014, Dr. Dr. –Ing. habil. Catalin Teodoriu
The Drilling time td, required to drill a given depth can be obtained by
separating variables and integrating.
Seperating variables gives;
Integrating and solving for td yields
Drilling Time
![Page 58: Class10-11upg2014](https://reader034.fdocuments.in/reader034/viewer/2022042821/55cf91a6550346f57b8f454a/html5/thumbnails/58.jpg)
Cf = drilling cost, $/ft
Cb= cost of bit, $/bit
Cr= fixed operating cost of rig, $/hr
tb= total rotating time, hrs
tc= total non-rotating time, hrs
tt= trip time (round trip), hrs
= footage drilled with bit, ft D
ft
$
D
)ttt(CCC
tcbrbf
The Drilling Cost Equation
![Page 59: Class10-11upg2014](https://reader034.fdocuments.in/reader034/viewer/2022042821/55cf91a6550346f57b8f454a/html5/thumbnails/59.jpg)
UPG 2014, Dr. Dr. –Ing. habil. Catalin Teodoriu
Cost per ft for one entire bit run
![Page 60: Class10-11upg2014](https://reader034.fdocuments.in/reader034/viewer/2022042821/55cf91a6550346f57b8f454a/html5/thumbnails/60.jpg)
UPG 2014, Dr. Dr. –Ing. habil. Catalin Teodoriu
Can pull bit after about 25 hr. ($42.50/ft)
- The precise pulling time is not critical
- Note that the cost in dollars per foot was $43.00 after 30 hr
Primarily applicable to tooth – type bits where wear rate is predictable
Economic Procedure
![Page 61: Class10-11upg2014](https://reader034.fdocuments.in/reader034/viewer/2022042821/55cf91a6550346f57b8f454a/html5/thumbnails/61.jpg)
UPG 2014, Dr. Dr. –Ing. habil. Catalin Teodoriu
Also used with tungsten carbide insert bits when inserts are brolken or
pulled out of the matrix
Unfortunately, wear rate with insert bits is unpredictable
Economically, the insert bit should be pulled when the
cost in $/ft begins to increase
Economic Procedure
![Page 62: Class10-11upg2014](https://reader034.fdocuments.in/reader034/viewer/2022042821/55cf91a6550346f57b8f454a/html5/thumbnails/62.jpg)
UPG 2014, Dr. Dr. –Ing. habil. Catalin Teodoriu
Bits pulled for economic reasons make it hard to obtain
wear information
Operator might pull bit after 120 hr of use but part of bit
might get left in hole.
Recovery is difficult. AVOID!
75% of rock bits are pulled green or before the bit is worn
out
Economic Procedure
![Page 63: Class10-11upg2014](https://reader034.fdocuments.in/reader034/viewer/2022042821/55cf91a6550346f57b8f454a/html5/thumbnails/63.jpg)
UPG 2014, Dr. Dr. –Ing. habil. Catalin Teodoriu
Variables:
-Type of Drill Bit
-Bit weight
-Rotary speed
-Bottom-hole cleaning
-Mud properties
Fixed factors:
-Rock hardness
-Formation pore pressure
Factors Affecting Penetration Rate
![Page 64: Class10-11upg2014](https://reader034.fdocuments.in/reader034/viewer/2022042821/55cf91a6550346f57b8f454a/html5/thumbnails/64.jpg)
UPG 2014, Dr. Dr. –Ing. habil. Catalin Teodoriu
Evaluate whether to fish or sidetrack?
- Assume one fishing attempt cost $60,000
- Assume sidetrack cost is $500,000
- Assume probability for success first attempt is 60%
- Assume probability for success second attempt is 40%
- Assume probability for success third attempt is 30%
Exercise
![Page 65: Class10-11upg2014](https://reader034.fdocuments.in/reader034/viewer/2022042821/55cf91a6550346f57b8f454a/html5/thumbnails/65.jpg)
UPG 2014, Dr. Dr. –Ing. habil. Catalin Teodoriu
EMV = probability of success time cost of fishing plugs probability of
failure times cost of failure of even event plus side track cost
EMV first attempt = .6 x $60k +.4 x $560k = $260k
- Since EMV < ST decide to fish
EMV second attempt = .4 x $120k +.6 x $620k = $420k
- Since EMV < ST decide to fish
EMV third attempt = .3 x $180k +.7 x $680k = $524k
- Since EMV > ST don´t fish third time
Fishing Exercise Results
![Page 66: Class10-11upg2014](https://reader034.fdocuments.in/reader034/viewer/2022042821/55cf91a6550346f57b8f454a/html5/thumbnails/66.jpg)
UPG 2014, Dr. Dr. –Ing. habil. Catalin Teodoriu
OFT = Time at which the fishing problem occured until
fishing should stop
Based on complex statistical studies of historical data, the
OFT can be calculated
Suprisingly, OFT is independent of location and
independent of the nature of the problem
Optimum Fishing Time (OFT)
![Page 67: Class10-11upg2014](https://reader034.fdocuments.in/reader034/viewer/2022042821/55cf91a6550346f57b8f454a/html5/thumbnails/67.jpg)
UPG 2014, Dr. Dr. –Ing. habil. Catalin Teodoriu
Calculate the OFT
SPE 22380
![Page 68: Class10-11upg2014](https://reader034.fdocuments.in/reader034/viewer/2022042821/55cf91a6550346f57b8f454a/html5/thumbnails/68.jpg)
UPG 2014, Dr. Dr. –Ing. habil. Catalin Teodoriu
All time depent fishing costs = $48,000/day = $2,000/hour
Cost of sidetracking to the same depth = $750,000
Example