Note: The PAS file formats attached to this Bulletin have been updated. The revised attachment has replaced the original.

NOTE: The references to documents as originally published in this Bulletin have been revised to reflect the current titles of the documents.

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Attachment - PAS file formats (updated to February 18, 2011)
-- PDF format
-- Excel format

Bulletin 2004-15

May 21, 2004

NEW WELL TEST CAPTURE (WTC) SYSTEM IMPLEMENTATION DATE REMINDER: CHANGES TO FINAL WTC PRESSURE ASCII STANDARD (PAS) FORMATS AND VERSION 4.0 PAS FILE BUSINESS RULES IMPLICATIONS

This bulletin is to remind industry that the implementation date for the new Well Test Capture (WTC) system incorporating the new PAS file formats is scheduled for July 5, 2004 .

As a result of errors recognized during the beta testing process, as well as suggestions from industry participants involved in the testing, some minor corrections and changes to the PAS file formats have been necessary. The PAS file changes are highlighted on the Alberta Energy and Utilities Board (EUB) Web site at WELL TEST (DATA) CAPTURE. To assist in the identification of the fields that have been changed, modified, or deleted from the PAS file formats initially issued with General Bulletin 2002-37 , the PAS file formats have colour-coding indicating the changed data elements. New additions are highlighted in green, fields that have been deleted are in red, and those changed or revised are in blue.

Please ensure that these changes are incorporated into the new Version 4.0 PAS files, as they may contain critical edits without which test data cannot be submitted.

Also, particular attention must be paid to all the business rules and edits in the new Version 4.0 PAS files. These business rules have been developed directly on the current EUB requirements or oil and gas well testing contained in

• EUB Directive 40: Pressure and Deliverability Testing Oil and Gas Wells Minimum Requirements and Recommended Practices ,
• EUB Directive 034: Gas Well Testing Theory and Practice ,
• EUB Directive 005: Calculating Subsurface Pressure via Fluid Level Recorders ,
• Oil and Gas Conservation Regulations , Clauses 11.070(1) through (5),
• Oil and Gas Conservation Regulations, Clause 11.100, and
• Oil and Gas Conservation Regulations, Clause 11.120(1)(c).

A discussion of the well testing requirements and the implications of not meeting these specific testing requirements is attached to this bulletin. It also reminds industry that there are opportunities for relaxation or relief from these requirements, provided that proactive justification is presented to EUB staff.

Industry questions and feedback can be sent by e-mail to EUB.WTC-Review@eub.gov.ab.ca. Please do not hesitate to give us your feedback. While responses to feedback are not always immediately forthcoming, the EUB does review all feedback and will provide a response. Feedback is also kept for future consideration during regulatory reviews and WTC system enhancements or changes.

[Original signed by]

Forrest Kvemshagen
Chief Information Officer
Information Systems and Services Branch

ATTACHMENT TO BULLETIN 2004-15

WTC PAS FILE BUSINESS RULES IMPLICATIONS FOR NONCOMPLIANCE

1 Background

The oil and gas industry and the Alberta Energy and Utilities Board (EUB) have noticed a general decline in the quality of well tests being conducted and submitted to the EUB. The EUB is concerned about the quality and usefulness of certain data, for example, how poor well test data could affect the EUB's Public Safety and Sour Gas (PS&SG) initiatives and ultimately the safety of Albertans. Similarly, industry has voiced concerns about the variety of and inconsistency in engineering practices used to meet testing and submission requirements and the general lack of enforcement of such requirements.

The discussion in this attachment addresses a number of areas where current well testing often fails to meet the intent of the requirements.

2 General Well Testing References

EUB Directive 040: Pressure and Deliverability Testing Oil and Gas Wells Minimum Requirements and Recommended Practices cites EUB Directive 034:  Gas Well Testing Theory and Practice and Directive 005: Calculating Subsurface Pressure via Fluid Level Recorders in many places for the technical rules of practice to be followed when designing, conducting, and interpreting gas and oil well deliverability and subsurface pressure tests.

Industry is reminded that these three guides continue to be the main technical documents for testing procedures when conducting EUB-required well tests, including the calculation of subsurface pressure measurements using fluid-level recorders.

Not meeting the requirements and rules of practice detailed in these guides could be considered as noncompliance, leading to enforcement action being taken.

3 Initial Deliverability Testing of Gas Wells

3.1 Multipoint Deliverability Testing

Directive 040 Section 1: Introduction states that "The well testing requirements defined in this Guide are minimum requirements and the EUB may request testing that exceeds these requirements, where a need has been identified." Later in Directive 040, Section 4.3.1: Recommended Practices for Gas Well Deliverability Tests provides guidelines for the type of deliverability test to be conducted and stipulates that "The initial test should be a multi-rate test when the anticipated extended AOFP of the well is 300 thousand cubic metres per day (10 ³ m ³ /d) (10.6 million standard cubic feet per day [mmscf/d]) or greater, or if turbulence is a factor." Directive 034 is explicit in stating that in most cases a multipoint test should be conducted on new wells if little is known of the well's flow capacity or the reservoir's characteristics.

Deliverability tests other than the initial test are left to the licensee/operator to design and conduct in accordance with  Directive 040  and Directive 034 .

The new WTC system has the above business rules and edits built in, and the system will not allow the submission of high flow capacity wells unless a multirate test has been conducted. Noncompliance could be a consequence.

However, if a well is clearly within an area for which the EUB has identified environmental or public/resident issues or where flare restrictions are in effect, industry may, upon written application and approval, be permitted to relax this multipoint test requirement to a single-point test requirement.

3.2 Testing Low Deliverability Gas Wells

Although Section 4.3 of Directive 040 stipulates that a sandface deliverability relationship is required for all producing gas wells, Section 4.3.4 allows for relaxation from a sandface to a wellhead requirement for wells where the stabilized wellhead absolute open flow potential (AOFP) would be 20 10 ³ m ³ /d (~710 thousand standard cubic feet per day [mscf/d]) or less and where liquid loading would not mask the well's downhole potential.

The EUB reiterates that a relaxation from the initial requirement for a sandface deliverability to a wellhead deliverability relationship is permitted for low productivity dry gas wells where the wellhead AOFP is 20 10 ³ m ³ /d or less (~710 mscfd).

The new WTC system will permit a wellhead AOFP for low productivity dry gas wells.

3.3 Extended/Transient AOF and Stabilized AOF

Section 4.3 of Directive 040 clearly states that for the initial deliverability relationship: "A stabilized rate is required to be a calculated value, based on the time to pseudo steady state. This calculation corrects the actual extended test rate to a lower estimated stabilized rate. Higher permeability reservoirs will have very little correction to stabilize, where lower permeability reservoirs will have a large correction. Although the time to pseudo steady state varies with the well geometry and reservoir shape, one can assume a well in the center of a one-section drainage area for a gas well; or if the data or mapping suggests a different drainage area, adjustments must be made as indicated in section 5 of EUB Directive 034: Gas Well Testing Theory and Practice."

Some confusion has existed as to which deliverability relationship must be reported to the EUB for an initial test. Often, the most practical and prudent method of conducting an initial deliverability test would involve flowing the well for an extended period of time rather than to complete pressure stabilization. An extended AOF can then be determined, and the stabilized relationship would be derived through calculations using the extended values with reservoir properties obtained from pressure build-up analysis on the well.

The new WTC system has business rules and edits requiring both an extended and stabilized deliverability relationship for an initial deliverability test. Without both relationships, the system will not permit the test to be submitted. Noncompliance could be a consequence.

4 Relaxation of or Exemption from Initial Deliverability Testing

The EUB recognizes that there may be instances where the data obtained from conducting gas well deliverability tests on new wells might be of limited value in relationship to the productivity of those wells or the stage of development and depletion of the reservoirs in which they are completed. Directive 040 and Directive 034 provide for relaxation of or exemption from initial well deliverability testing requirements for low productivity gas wells, as described in item 3.3 above.

Section 4.3.4 of Directive 040 elaborates on other circumstances when a sandface AOF may not be required. Well-established reservoirs for which sufficient deliverability data exist to correlate well to well flow capacities from geological and reservoir pressure data may be candidates for the relaxation of subsurface testing. In such cases, when initial deliverability test data clearly provide little additional knowledge to the depletion management of the reservoir, licensees are encouraged to apply for relaxation above the standard 20 10 ³ m ³ /d limit.

Such applications must be made in writing on an individual well or pool basis, with supporting documentation, data, and information to support the exemption request, including the impact of the exemption on conservation and equity and a description of any alternative testing proposal and its appropriateness in meeting the testing intent. A wellhead deliverability relationship with a good initial pressure might be considered an acceptable alternative, but there may be cases when a total exemption from the initial deliverability test might be considered. The EUB will review and approve applications on an individual case-by-case basis. In no case should approval of such requests be assumed, and unless and until the EUB does grant approval, all requirements must be met. There is no retroactive approval of testing relaxations.

Directive 040 , Section 4.3.5, also allows industry to apply for blanket relaxation or exemption from testing on a regional, formation, or pool basis if it can demonstrate that further well test data provide little future value for the depletion strategy within the region. An application must provide sufficient technical and reservoir engineering analysis to exhibit that further testing is not needed for the depletion strategy within the region.

Industry must be proactive in applying for well testing relaxations or exemptions if deemed reasonable.

A proactive view to an identified need for well test data can be very effective and cost efficient rather than doing the bare minimum of providing a test that is incomplete, inaccurate, and of no value just to meet an EUB requirement.

5 Inflow Performance Relationships for Flowing Oil Wells

Directive 040 , Section 4.3, indicates that there is no deliverability test requirement for oil wells, but where a test such as an Inflow Performance Relationship (IPR) is determined for an oil well, the test data and its interpretation must be filed with the EUB, as directed by Clause 11.120(1) of the Oil and Gas Conservation Regulations .

Because flowing oil well IPRs provide essential oil well flow capacity information, it is vital that these data be available for the public record. IPR or any other oil well test data and analysis must be submitted to the EUB.

The new WTC system will accept IPR data for oil wells both in PAS and image file format. IPR data taken but not submitted would place the licensee/operator in noncompliance, leading to enforcement action.

6 Well Fluid Analysis Requirements

Directive 040, Section 3.5: Gas and Fluid Analysis, provides specific requirements for the collection and submission of fluid analyses, including both gases and liquids. Fluid analyses are particularly important, as they are the source of sour gas concentrations that are used in many of the initiatives of PS&SG and in business processes related to the public safety of Albertans.

The EUB requires that samples of all fluids (gas, oil, bitumen, and water) be collected, analyzed, and submitted in accordance with the requirements stated in Directive 040, Section 3.5, as well as in Clause 11.070(2) of the Oil and Gas Conservation Regulations. In particular, note that a gas analysis must be submitted to the EUB within 90 days of placing a well on production for all wells that, when completed, are not within an existing pool as defined by an EUB G-Order. In addition, if a well produces both gas and condensate, a recombination analysis must be submitted.

With the implementation of the new WTC system, industry will be required to include a gas analysis PAS file to meet the initial deliverability testing requirements for all new undefined gas wells. New wells completed in a clearly defined and developed pool may submit a representative analysis from an adjacent well, if written justification is provided with the test. The implication of not meeting this submission requirement will be noncompliance, with enforcement action applicable.

The EUB does not expect the submission of fluid analyses taken on a frequent basis (monthly) for metering/measurement calibrations for monthly production reporting volumes unless the composition of the reservoir fluids has changed. However, it is good practice to conduct and provide at least two fluid samples, which could provide a better compositional average than just one analysis.

7 Compliance

Industry has expressed significant concern to the EUB respecting the results of testing conducted but not being submitted to the EUB. Directive 040, Section 4.9: Submission Requirements, clearly states: "Licensees/Operators are required to submit to the EUB, in the appropriate electronic, PAS format, all pressure and deliverability tests, DSTs, reservoir fluid analysis (oil, gas, condensate, recombination's, water) conducted including those tests not required by this guide ( Directive 040 ) and as per section 11.120 of the Oil and Gas Conservation Regulations. " While initial tests are of particular importance, it is critical that all tests conducted on all wells be submitted in the proper manner with all pertinent information.

Directive 040, Section 4.9: Submission Requirements, also states: "Where the EUB determines that a test has been conducted and not submitted, the matter becomes a non-compliance issue, subject to the measures detailed in Section 6 (Compliance to the Minimum Requirements) of this Guide."

The prescribed timing of submissions specified in Directive 040 is within 90 days of completing the fieldwork for pressure and deliverability tests, 30 days from the finished drilling date for DSTs, and 45 days from the sampling date for an analysis of any well fluid.

If the EUB determines that a test has been conducted and not submitted within the specified time requirements, the licensee will receive a notice letter starting the compliance process, subject to the measures detailed in Directive 040 , Section 6.

The implications of not submitting all test data gathered will be noncompliance, followed by enforcement action. After December 2004, should the EUB become aware of well test data that has not been submitted, the offending licensee will be subject to the same noncompliance consequences and enforcement ladder as is used for initial well testing requirements. Should these data form part of an application to the EUB, the processing of the application may be suspended pending the submission of the test data through the usual WTC system process.

Attachment - PAS file formats (updated to July 29, 2005)
-- PDF format
-- Excel format