Guidance for Complying with BOEM NTL No - Society of ... · Web viewIf modeling a reservoir with...

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Guidance for Complying with BOEM NTL No. 2010-N06 on Worst Case Discharge for Offshore Wells Society of Petroleum Engineers September 22, 2010 Chair: Tim Magner, Chevron Committee Members Jonathan Harris, Apache Corporation James Wells, ATP Oil & Gas Corporation Ron Harvey, Century Exploration New Orleans, Inc. Curt Killinger, Challenger Minerals Inc. (CMI) / Transocean Connie Bargas, Cobalt International Energy, L.P. Dan Smallwood, ConocoPhillips Phillip Bednarz, ExxonMobil Martin Wolff, Hess Corporation Ted Skinner, Marathon Donny Torres, Newfield Exploration Stuart Hara, Shell John Leonard, Stone Energy Ashley Africa, Woodside Energy Akhil Datta-Gupta, Texas A&M University Tad Patzek, University of Texas Richard Hughes, Louisiana State University 1

Transcript of Guidance for Complying with BOEM NTL No - Society of ... · Web viewIf modeling a reservoir with...

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Guidance for Complying with BOEM NTL No. 2010-N06 on Worst Case Discharge for Offshore Wells

Society of Petroleum Engineers

September 22, 2010

Chair: Tim Magner, Chevron

Committee Members

Jonathan Harris, Apache Corporation

James Wells, ATP Oil & Gas Corporation

Ron Harvey, Century Exploration New Orleans, Inc.

Curt Killinger, Challenger Minerals Inc. (CMI) / Transocean

Connie Bargas, Cobalt International Energy, L.P.

Dan Smallwood, ConocoPhillips

Phillip Bednarz, ExxonMobil

Martin Wolff, Hess Corporation

Ted Skinner, Marathon

Donny Torres, Newfield Exploration

Stuart Hara, Shell

John Leonard, Stone Energy

Ashley Africa, Woodside Energy

Akhil Datta-Gupta, Texas A&M University

Tad Patzek, University of Texas

Richard Hughes, Louisiana State University

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Table of Contents

Disclaimer....................................................................................................................................................3

Background..................................................................................................................................................3

Calculation Procedure.................................................................................................................................5

Step 1: Determine Uncontrolled Flow for each hole section...................................................................5

Step 2: Determine the Time Required to Drill a Relief Well.....................................................................7

Step 3: Provide a Rate Profile for Production Decline.............................................................................7

Step 4: Calculate the Total Spill Volume..................................................................................................7

Recommended Submission Outline.............................................................................................................8

Data and Documentation Requirements.....................................................................................................9

Appendix A: Useful definitions and Clarifications......................................................................................14

Appendix B: Useful References.................................................................................................................15

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Disclaimer

This document was created by an SPE Committee in response to the U. S. Department of Interior Bureau of Ocean Energy Management (BOEM) Notice to Lessees (NTL) No. 2010-N06 requiring Worst Case Discharge Calculations (WCD) and documentation. This guidance is not an endorsement of the methodology put forth by the NTL on a Worst Case Discharge Calculation.

This document is intended to be only a guideline and it is still up to each company responsible for making the submittal to the BOEM to understand the regulations and ensure that specific data requirements have been met. It is anticipated that a continuing series of Frequently Asked Questions (FAQs) and or regulations relating to NTL No. 2010-N06 will be issued over the next few months to clarify specific points and give more detail on the acceptable form for submittals.

It is recommended that an SPE committee be formed to develop global technical guidance on best practices to estimate potential spill volumes from uncontrolled well events. In addition, this document identifies several specific topics where value could be gained by BOEM working with Industry to both advance the predictive techniques and come to agreement on the realistic modeling of wellbore phenomena.

Background

In the wake of the Deepwater Horizon incident, the BOEM has revised and increased the requirements for Worst Case Discharge Scenario calculations. This draft guidance document was created by an SPE Committee during a Workshop held in Houston, Texas on August 25 and 26, 2010 and organized jointly by SPE and the Offshore Technology Research Center. The intent of this document is to assist Industry with conformance to the NTL requirements in a manner that will promote transparent, complete and uniform calculations for all offshore operations in United States waters. NTL No. 2010-N06 states:

“Due to the explosion and sinking of the Deepwater Horizon, the resulting deaths of 11 people, and changing conditions caused by the blowout of the BP Macondo prospect weIl that was being drilled by the Deepwater Horizon, the MMS (now BOEM) requires additional information concerning your planned activities.

Pursuant to the regulations at 30 CFR 250.284 and 250.201 (b), the MMS may require you to submit additional information necessary to evaluate your proposed or existing plan or document. In accordance with the regulations, the MMS may also require you to provide information to demonstrate that you have planned and are prepared to conduct your proposed activities in a manner that conforms with all applicable federal laws and

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regulations, is safe, conforms to sound conservation practices and does not cause undue or serious harm or damage to the human, marine or coastal environment pursuant to 30 CFR 250.202. This NTL describes the information you must submit to MMS.”

The purpose of each submittal is to provide BOEM with full and complete documentation to assess each proposed drilling well should another major spill happen. The discussion should include the estimated flow rate, the maximum duration of potential uncontrolled flow and the total volume. This Total Spill Volume and Worst Case Discharge Scenario Rate will be used to address each company’s Oil Spill Response Plan portion of the regulations.

The documentation is expected to include a complete description of the potential worst case discharge as required by 30 CFR 250.213(g) and 250.243(h) and as supplemented by several recent FAQs concerning the NTL (see Appendix).

Documentation requirements in the NTL state that each submittal must:

“Describe the assumptions and calculations that you used to determine the volume (daily discharge rate) of your worst case discharge scenario required by 30 CFR 250.219(a)(2)(iv) (for EPs) or 30 CFR 250.250(a)(2)(iv) (for DPPs and DOCDs).

Provide all assumptions you made concerning the well design, reservoir characteristics, fluid characteristics, and pressure volume temperature (PVT) characteristics; any analog reservoirs you considered in making those 3 assumptions; an explanation of your reasons for using those analog reservoirs; and the supporting calculations and models you used to determine the daily discharge rate possible from the uncontrolled blowout portion of your worst case discharge scenario for both your proposed or approved EP, DPP or DOCD worst case discharge scenario and your proposed or approved regional Oil Spill Response Plan (OSRP) worst-case discharge scenario used in your comparison.”

The NTL also states that this calculation is required for both oil and gas wells. The regulatory definition of “oil” includes “oil, condensate that has been injected into a pipeline, or gas and naturally occurring condensate.” Thus, gas wells are not exempt from the calculation.

BOEM has stated that they will review each submittal as well as conduct an independent calculation. An operator’s omission of information for the calculation is likely to result in the BOEM staff interpreting their own inputs for the Worst Case Discharge calculation. The Worst Case Discharge calculation and approval process is expected to become more explicit as BOEM states reasons for not approving specific permits. BOEM has committed to share weekly updates of what items have caused these submissions to be recycled. Revised formal regulations including additional clarifications are expected to be issued in September, 2010. BOEM has stated that they expect to spend about 150 man-hours (one man-month) per submittal.

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Calculation Procedure

It is necessary to consider each hole section that will be drilled as a possible candidate for the Worst Case Discharge Scenario during an Uncontrolled Flow event. It is recommended that the Worst Case Discharge Scenario evaluation includes these four steps:

Step 1: Evaluate all potential hydrocarbon-bearing intervals in each section of the hole to be drilled and determine the Uncontrolled Flow for each hole section following the guidelines described below. The hole section with the highest Uncontrolled Flow Rate scenario will be considered the Worst Case Discharge Scenario for reporting.

Step 2: Estimate the time required to drill a relief well for the hole section to be considered for Worst Case Discharge Scenario reporting.

Step 3: For the hole section considered as the Worst Case Discharge Scenario for reporting, provide a single rate profile for production decline or depletion for all zones including those which may be commingled.

Step 4: From the flow rate projection determined in Step 3, calculate the total potential spill volume over the time required to kill the well.

Note that BOEM requires both hardcopy and electronic copy formats for all documentation. The submittal should include documentation files as appropriate to identify all input variable necessary to recreate the calculation.

Step 1: Determine Uncontrolled Flow for each hole section

The NTL indicates that the Worst Case Discharge Scenario should include all hydrocarbon-bearing zones in each open-hole section as it is planned to be drilled. The Uncontrolled Flow should include the combined flow from all zones in each open hole section that could be commingled in an uncontrolled flow scenario. It is to be assumed that each hole section is fully drilled when the event occurs.

Clarifications from BOEM indicate that calculations are not limited to those zones defined as “productive” (>15’ of hydrocarbons) by the regulations. BOEM has stated that “all zones capable of flow” should be included. There has been no additional guidance on how thick a zone must be to add materially to the Worst Case Discharge Scenario calculation.

Although initial guidance from BOEM was to include all sands that might flow in each open hole section, the BOEM has now been seen to challenge inclusion of water sands in the calculation of the commingled

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flow rate. Therefore, the inclusion of water-bearing sands in the WCD scenario should be strongly supported by offset and analog data. Note that the inclusion of water sands can result in a situation where the highest calculated oil rate does not occur during the early portion of the uncontrolled flow. If water sands are included but deplete prematurely, this situation could result in an increasing oil discharge rate as time passes during the event.

For selection of input parameters for each zone, the intent is that the output of the flow rate calculation should approximate the best technical estimate. The WCD rate and resulting total potential spill volume estimates will be used for logistics planning in each company’s Oil Spill Response Plan and should be best estimates based on all technical, analog, and mechanical data available.

Recommendations specific to analog data selection have largely been avoided in this document. The SPE Committee considers that the complexity of appropriate analog data selection to cover both Development and Exploratory wells precludes hard guidelines. However, the FAQ documents make it clear that the BOEM will rely heavily on BOEM internal data spanning all GOM field developments. It has also been made clear that they consider nearby well or field analogs completed in a similar lithology more appropriate than far-field or regional data. It is highly recommended that each company consider both local analogs as well as Industry available database analogs as might be appropriate for each scenario.

Worst Case Discharge Scenario rates should be based on uncontrolled flow at the mud line with a hydrostatic water column or atmospheric pressure at sea level if well work is on an existing platform. Worst Case Discharge Scenario rates for development wells should be calculated on a well-by-well basis. In situations where work is being conducted from a drillship or mobile offshore drilling unit, it is assumed that the vessel and riser are disconnected and any wellhead and well control equipment at the mudline has been damaged to the point where it provides no physical restriction to flow.

The NTL specifies that the hole section to be considered for the Worst Case Discharge Scenario will be the section with the greatest discharge potential. In the context of the BOEM FAQ document, the SPE Committee interprets this to mean the hole section with the highest Uncontrolled Flow Rate rather than the Highest Total Volume over the time period of the event.

For the selected hole section, detailed documentation must be submitted as outlined below. For other sections of the hole, documentation should be limited to data necessary to support the logic behind the model for sand and hydrocarbon presence and, if hydrocarbons are thought to exist, data to support the Uncontrolled Flow Rate calculation for that section

The Uncontrolled Flow calculation should be carefully checked for quality control. This may include ensuring selected flow correlations don't show unrealistic gradient anomalies, verifying flow exit velocities are sub-sonic and confirming that computed PVT properties from correlations are consistent with analogs. Any inconsistencies in data submissions or a lack of clarity in describing assumptions will likely result in delay of approval by the BOEM.

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Step 2: Determine the Time Required to Drill a Relief Well

For the section of the hole selected for Worst Case Discharge Scenario reporting, the best estimate of the time required to drill a relief well and kill the uncontrolled flow. The time required should include:

- days to secure a rig, de-mob/mob and be ready to drill at the relief well site, plus- time to drill the relief well and intersect the blowout well at the base of the previous casing

point, plus- days to kill and cement the blowout well

Ensure that sufficient documentation is included to confirm the expected days to drill the relief well to the target depth and clearly show the calculation of the total days required.

Step 3: Provide a Rate Profile for Production Decline

The NTL requires reporting of the estimated flow rate, the maximum duration of potential uncontrolled flow and the total volume. Most wells will initially flow at a high unconstrained rate and then experience rate decline either due to transient effects, reservoir boundaries or depletion. A rate profile for production decline for the hole section to be considered for Worst Case Discharge Scenario reporting may be estimated several ways. In order to speed up the approval process, it is recommended that the most simple and straightforward analogs and analytical methods be used. However, wells with well-defined geologic models may use simulation or material balance models to estimate rate decline with pressure depletion.

If using a limited or bounded reservoir model, clearly indicate the maximum drainage area and show how it conforms to structure maps and interpreted fault or stratigraphic boundaries. If modeling a reservoir with production history, include sufficient reservoir performance or history match data to substantiate the expected pressure decline with rate and cumulative production. For wells with no immediate offsets or an uncertain geologic model, clearly provide supporting assumptions for any pressure depletion or water production expected within the calculation period.

Step 4: Calculate the Total Spill Volume

The total potential spill volume to be reported for discharge scenario reporting will be defined as the sum of the production from the flow rate profile over the time required to kill the well. This is the total volume to be addressed by each company’s Oil Spill Response Plan. Oil production volumes should be reported in stock tank barrels of oil.

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Recommended Submission Outline

The NTL requires a significant increase in documentation requirements. For the section of the hole that will be used for Worst Case Discharge Scenario reporting, it is necessary to estimate the well, reservoir and fluid properties as outlined below. According to the 10 August 2010 FAQ: “BOEM recommends including a Summary Sheet with your data submittal that states the parameters you used to derive the worst case discharge scenario.”

A summary table of input data and nodal output graphs to document the Uncontrolled Flow for each hole section considered as the source of the Worst Case Discharge Scenario should be included to clearly identify which hole section would result in the highest discharge rate. Detailed documentation of analogs and rate profiles is required only for the hole section used for Worst Case Discharge Scenario reporting. Documentation for all other hole sections should be properly archived.

1) Introduction and Summarya. Introduction with summary of results and calculated rates and volumes

2) Discussion of Prospect/Field and Summary of Well Plana. Prospect or Field Summaryb. Well Objectivesc. Well Plan Overview

i. Discussion of each hole section, noting the presence or absence of hydrocarbon bearing zones in each section.

3) Description of Worst Case Discharge Scenario Rates and Volumesa. Clearly identify which hole section will be considered for the Worst Case Discharge

Scenario reporting b. Discuss intervention and relief well plans and time required to kill the wellc. Discuss the production rate projection d. Include a summary sheet documenting the calculation of the total potential spill volume

over the time to kill the well.4) Worst Case Discharge Scenario Documentation - as specified by the NTL, you must document

all assumptions supporting the evaluation (see next section for discussion):a. Reservoir characteristics;b. Reservoir pressure data;c. Reservoir drive mechanisms;d. Reservoir drainage area and depletion rates;e. Wellbore completion configurations;f. Casing and open-hole sizes;g. Casing and open-hole absolute roughness;h. Production history;i. Static and flowing pressures and temperatures;j. Mechanical skin damage;

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k. Water intrusion;l. Coning;m. Formation sloughing;n. Bridging;o. Pressure-volume-temperature characteristics of the fluid;p. Hydrostatic pressure

5) List of attached displays and input/output filesa. Include a list of all displays referenced in the document.b. Include files for each software package used and a hard copy report.

6) Attach displays, cross sections and maps in digital and hardcopy formata. Include summary calculations describing flow potential of zones b. Examples of typical maps, diagrams and tables are illustrated in the attached BOEM-

issued FAQ documents.

Data and Documentation Requirements

Specific data and documentation requirements are:

(1) Hole sections not included in the Worst Case Discharge Scenario calculations

For hole sections that will not contain hydrocarbon bearing sands or those sections not used in the Worst Case Discharge Scenario, a geological and offset well discussion must be included along with sufficient displays to justify this conclusion.

(2) Hole section included in the Worst Case Discharge Scenario calculations

For the hole section to be used in Worst Case Discharge Scenario reporting, provide support for the following:

(a) reservoir characteristics;

Include a description of each target sand as it relates to the general depositional environment for the field or prospect. Note offset wells, interpreted faults or channel boundaries and clearly show any reservoir limits that may reduce flow potential.

Include structure maps for each potentially producible sand to be encountered (tops and base) which clearly identify the surface and bottom-hole location of each well. Net sand isopach maps should be included or a statement should be made concerning the average net sand over the drainage area. Clearly indicate the measured depth thickness expected to be penetrated, as well as the net sand thickness used for the flow rate calculation.

Include one or two seismic cross-sections showing the well site location with reference to any offset wells. Clearly show prospective oil-water and gas-oil contacts on cross-sections and maps.

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Identify the seismic survey permit number used in the submitted EP seismic snap shots and indicate whether the data had been reprocessed.

Include log cross-section clearly depicting all anticipated hydrocarbons bearing zones. Give one deterministic estimate of net sand for each zone and cite support for this value. Give one deterministic estimate of average porosity and permeability for each zone and cite support for these values. It is understood that BOEM has established an internal database to estimate rock and fluid properties for all known productive geologic horizons. Include a summary table of rock and fluid properties used for each zone and clearly indicate the source of these values, whether internal estimates or from an Industry available database. Clearly show the difference between relative vs. absolute permeability as these values may be easily confused.

No guidance has been given on preferred scale of maps and presentation materials – only that they be large enough to be legible. Documentation should follow the guidelines commonly used in EP, DPP and DOCD submittals. Note that a FAQ published on August 10, 2010 for this NTL contains example displays showing what level of detail the BOEM expects.

(b) reservoir pressure and temperature data;

Provide an estimate of initial reservoir pressure and temperature at the subject well location and cite support for this value. Initial pressure and hydrocarbon saturation conditions are assumed unless depletion can be documented in the same reservoir.

(c) reservoir drive mechanisms;

State expected reservoir drive mechanism and cite support for this assumption.

(d) reservoir drainage area and depletion rates;

If using a limited or bounded reservoir model, clearly indicate the maximum drainage area and show how it conforms to faults or stratigraphic reservoir limits on structure maps. If using a material-balance or simulation model to predict performance, clearly document key assumptions and inputs to allow. As the BOEM has stated that they will create an independent model with internal software, any input details that are not clearly documented will be subject to interpretation. In reservoirs that have produced, include sufficient production history data and show a history match to substantiate pressure decline predictions with rate and cumulative production.

(e) wellbore completion configurations;

Give a general description of the drilling plan in the Worst Case Discharge Scenario hole section. Include directional survey plan clearly showing planned well location and deviation. BOEM requires that the Worst Case Discharge Scenario assumes open-hole conditions, regardless of actual well plans. Each hole section will be considered to be fully drilled per the drilling plan at the time of the event.

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(f) casing and open-hole sizes;

Worst Case Discharge Scenario calculations will assume open-hole conditions over each hole section to be separately drilled and cased. Once casing is set over each hole section, the productive zones behind pipe are no longer considered to have the ability to contribute for the remainder of the operation. Guidance from BOEM is that the Worst Case Discharge Scenario should not include tubing or completion equipment in the wellbore and each flow scenario should be modeled with no restriction to flow at the wellhead.

Include a wellbore diagram clearly showing casing points, pipe characteristics and hydrocarbon bearing zones expected in each hole section. Clearly indicate which hole section is used for Worst Case Discharge Scenario calculations. For deepwater wells, it will be useful to clearly indicate the depth below mudline of each hole section.

(g) casing and open-hole absolute roughness;

State expected absolute roughness for the well design and cite support for these values. Make sure friction factors are appropriate for each section of pipe and open hole. Industry guidance is to hold these values constant.

(h) production history;

If using a material balance or simulation model to predict performance, include sufficient production history data and show a history match to substantiate pressure decline predictions with rate and cumulative.

(i) static and flowing pressures and temperatures;

Include an output table from the systems analysis software showing Worst Case Discharge Scenario rate and flowing pressures. BOEM requests that the flowing pressures at the reservoir, wellhead and each change in the internal wellbore diameter be clearly marked. Include graphs of the nodal analysis. A check that exit velocity does not exceed sonic flow velocity is recommended.

(j) mechanical skin damage;

BOEM guidance is to set mechanical or completion skin to zero.

(k) water intrusion;

In an open-hole Uncontrolled Flow scenario, any hydrocarbon zones with gas/oil or oil/water contacts should be modeled to flow all phases. Water inflow will tend to reduce the total oil rate while gas inflow may impact the total liquid rate from any given zone. If an initial water or gas saturation is expected in hydrocarbon bearing zones at the planned penetration point, clearly show cross-sections, production history and reservoir performance predictions that

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substantiate this model. In general, flow assurance issues such as asphaltene deposition and gas hydrate blockage will be assumed not to occur.

The inclusion of water-bearing sands in the WCD scenario should be strongly supported by offset and analog data. As described above, the BOEM has now been seen to challenge inclusion of water sands in the calculation of the commingled flow rate.

(l) coning;

In general, no increase in water or gas saturation in the wellbore due to coning will be assumed to occur within the calculation period. However, if a nearby oil/water or gas/oil contact can be documented near the expected penetration point, reservoir modeling can be used to estimate inflow of different fluid phases. If water or gas coning is expected in hydrocarbon bearing zones, clearly show cross-sections showing contacts, production history and reservoir performance predictions that substantiate this model. Guidance from the BOEM is that this prediction should be illustrated with nearby and appropriate analogs if this argument will be invoked.

(m) formation sloughing;

BOEM guidance is to assume no formation sloughing or hole collapse within the calculation period. Although there is a high likelihood of formation solids production at high rates, the effect of solids production on hole conditions cannot be reliably estimated for most wells. Hole size will be assumed to be constant at the drilled diameter.

(n) bridging;

If available, mechanical earth models or flux calculations may be used to estimate when an open hole section would collapse and bridge off; however, guidance from the BOEM is that this prediction should be illustrated with nearby and appropriate analogs if this argument will be invoked. If available and appropriate, include a detailed history of the analog event along with core photos and descriptions of the failed intervals, if available.

(o) Pressure-volume-temperature characteristics of the fluid;

Include a table of fluid properties used in the Worst Case Discharge Scenario calculations for each zone. In lieu of measured PVT data, industry accepted correlations can be used to estimate fluid PVT properties. Clearly indicate which correlations are being used.

Show oil properties at reservoir condition including bubble point pressure, Boi, Rsoi, viscosity of oil and oil compressibility, API gravity and specific gas gravity. Cite support for these values. Note that many available oil viscosity correlations are considered relatively coarse. Since oil viscosity can be a key component of the Worst Case Discharge Scenario flow rate calculation, viscosity correlations matched with analog fluids are preferred.

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For gas reservoirs, show gas properties at reservoir conditions including Bgi, API gravity of condensate, specific gas gravity, gas compressibility (z) factor and yield (bbl/mmcf). Cite support for these values. For Exploratory situations, consider that seismic inaccuracies in sub-salt reservoirs may lead to significant uncertainties in the estimation of fluid and reservoir characteristics modeled from seismic.

(p) hydrostatic pressure;

Hydrostatic pressure of seawater can be assumed to be water depth times a seawater gradient of 0.445 psi/ft.

(3) Summary Documentation

The BOEM recommend inclusion of a summary sheet documenting the parameters listed above and a table or paragraph clearly stating the Worst Case Discharge Scenario rate, maximum duration of potential uncontrolled flow and the total potential spill volume. Identify commercial or internal software packages used in making all rate and volume calculations. Current guidance from BOEM indicates that they do not require copies of input decks from each software program used although, as noted above, all input documentation necessary to recreate the estimates should be provided in a clear and organized manner.

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Appendix A: Useful definitions and Clarifications

Absolute Open Flow : The maximum flow rate a well could theoretically deliver in 24 hours with zero pressure at the middle of the flowing interval and no friction or fluid column weight holding the well back. The term is commonly abbreviated as AOFP.

Uncontrolled Flow: The maximum flow rate a well could deliver in 24 hours at the minimum possible surface or mud line pressure considering all practical aspects of the well design, reservoir and fluid properties but with no choke.

Worst Case Discharge: Discharge of the hole section with the highest estimates based on Uncontrolled Flow calculations. Absolute Open Flow estimates are useful to compare the flow capacity of wells without physical constraints, but have little meaning otherwise. These two values are easily confused by people who do not routinely work with the concepts.

NTL: Notice to Lessees and Operators

WCD: Worst Case Discharge

BOEM: Bureau of Ocean Energy Management

MMS: Minerals Management Service

EP - Exploration Plan

DOCD - Development Operations Coordination Documents

DPP: Development and Production Plan

APD: Application for Permit to Drill

CFR: Code of Federal Regulations

OSRP: Oil Spill Response Plan

PVT: Pressure-volume-temperature

FAQ: Frequently Asked Questions

SPE: Society of Petroleum Engineers

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Appendix B: Useful References

1. Notices to Lessees and Operators (Chronological Order)

http://www.gomr.mms.gov/homepg/regulate/regs/ntls/ntl_lst2.html

FAQ NTL 2010-N06 August 10, 2010

NTL 2010-N06 June 18, 2010

2. Electronic Code of Federal Regulationswww.gpoaccess.gov/ecfr/ References to Federal Code of Regulations cited in the NTL’s and FAQ’s to NTL’s.

3. Well Permits Subject to Increased Safety Measures and Updated Blowout and Worst Case Discharge Scenarios

http://www.boemre.gov/homepg/offshore/safety/well_permits.html

4. Increased Safety Measures for Energy Development on the Outer Continental Shelf and other documents from BOEMRE Forums on Offshore Drilling.

http://www.boemre.gov/forums/library_resource_material.htm

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This document contains general guidance for calculating the worst-case discharge and providing the information requested by the Bureau of Ocean Energy Management in its NTL No. 2010-N06. The Society of Petroleum Engineers, its members, and the drafters of this document are not, and are not engaged in, rendering legal, technical, or other professional services or advice to any person or entity that references this document. If such advice or assistance is necessary, the services of an appropriate qualified professional should be retained. Neither SPE, its members, nor any drafter of this document makes any claim, representation or warranty, express or implied, as to the completeness, correctness or usefulness of the information in this document or that the information contained in the document will produce any particular results with regard to the subject matter contained therein, or that the contents of the document satisfy requirements of NTL No. 2010-N06, or any federal, state, or local laws. Participation in the drafting of this document or use or reference to this document by any person or entity is not intended to imply endorsement of the requirements of NTL No. 2010-N06 or agreement that any of those requirements are in accordance with any federal, state or local laws.

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