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Informational Letter IL 96-02

23 February 1996

TO: All Oil and Gas Operators

PROGRESS REPORT REQUIREMENTS FOR MISCIBLE FLOOD SCHEMES

This informational letter contains revised reporting requirements for enhanced oil recovery (EOR) schemes that use a miscible flood (MF) displacement process. The Alberta Energy and Utilities Board (EUB), with input from all MF operators and the Alberta Department of Energy (DOE), has developed a two-part reporting process to address the unique data requirements, operations, and royalty administration of these floods.

Reporting Process

Part 1 of the new reporting process is an annual data submission which includes only data elements that cannot be internally generated by the EUB (see Table 1). This minimum data requirement should significantly reduce the time and effort needed by operators to compile data and check it for consistency.

Part 2 is an annual meeting where the scheme operator is expected to make a presentation on recent scheme performance, compliance with approvals, technical matters, and future plans (see Table 2). The major benefit of the meeting format is that discussions and follow-up will occur much closer to actual events and operations in the field. Another benefit is the opportunity for all stakeholders (scheme operator, EUB, and DOE) to participate in joint discussions respecting a scheme.

Reporting Categories

Recognizing that reporting requirements should be tailored to suit the type of miscible displacement and scheme maturity (in terms of both injection phase and royalty administration), eight reporting categories have been defined:

(1) see "Removal of Chase Gas Requirements for Horizontal Schemes"

(2) Blowdown - EUB has removed requirement for pressure maintenance

The Part 1 Data Submission Requirements and the Part 2 Annual Meeting Requirements for each reporting category are listed in Tables 1 and 2, respectively.

Removal of Chase Gas Requirements for Horizontal Schemes

The EUB has decided that operators should be given full flexibility respecting chase gas injection in horizontal schemes, for the following reasons:

• In most situations, the primary purpose of chase gas injection is to recover injected solvent, not to improve oil recovery. Most horizontal floods demonstrate early and significant solvent breakthrough, due to the high degree of gravity override in the reservoir; therefore, miscible displacement will likely end very soon after chase gas injection commences.
• In some situations, chase-gas injection may serve to improve oil recovery by stripping intermediates from residual oil and/or providing some immiscible displacement. These potential benefits, however, are difficult to quantify without actual field data.
• Operators have demonstrated a desire to optimize chase-gas injection volumes. Industry has generally moved towards smaller and more variable chase-gas banks sizes (on a pattern basis), and in some schemes, terminal water injection immediately following solvent placement. There does not appear to be any compelling conservation reason for future EUB intervention/review of this optimization process.

The EUB will implement this change by removing the minimum chase gas bank and water-alternating-gas (WAG) ratio, clauses, from the appropriate approvals.

Implementation

How will reporting be scheduled?

EUB staff will contact individual scheme operators to schedule the Part 1 data submissions and Part 2 annual meetings. Operators should try to arrange events so that the results of annual pressure surveys and the data submissions are filed with the Board in advance of the annual meeting.

Who should attend?

The annual meeting will be coordinated by EUB staff and will include,as a minimum, representatives of the scheme operator, EUB,and DOE staff. In keeping with the EUB's mandate to optimize the recovery of oil and gas reserves, we also encourage the attendance of operators of schemes in similar geological settings (i.e. Beaverhill Lake, Keg River, Nisku, Gilwood, etc.) who may benefit from these meetings. However, any attendants beyond EUB and DOE staff will be at the discretion of the scheme operator.

Where will the meetings occur?

The meetings are to be held in Calgary at the EUB offices. If another location is necessary or preferred, arrangements should be made by the scheme operator and the EUB and DOE staff should be notified at least two weeks in advance.

How will the presentation be documented for the public record?

Documents that will become a part of the public record include, the Part 1 data submission, material presented at the annual meeting, and any materials filed with the Board subsequent to the meeting as an undertaking or in response to deficiencies.

When will schemes qualify for exemption (reporting categories 7 and 8)?

Written requests for reduced frequency or exemption from reporting (Part 1 and/or Part 2) will be considered by the EUB using the following guidelines:

• schemes without significant performance or compliance (with the terms of the approval) issues,
• schemes without significant potential for operational changes or expansion,
• schemes that have progressed to terminal phases (water or blowdown),
• schemes that are deemed a technical failure (insignificant or zero incremental oil recovery),
• satisfactory data submission reporting (in case of Part 2 exemption).

Written requests for exemption will also be referred to DOE for comment.

Compliance

The EUB expects that the revised reporting requirements for miscible floods will have a number of benefits for all stakeholders, especially in these times of reduced resources. Over the past decade, the quality and timeliness of miscible flood progress reports have been inconsistent, in part, due to outdated requirements. Having reached a new consensus on the data and format required to effectively manage miscible floods, the EUB is hoping that many reporting concerns are behind us. In the event that non-compliance concerns reappear, the EUB will take appropriate action to enforce these new requirements.

Questions should be directed to Cheryl Adolf at 297-8561.

Yours truly,

[Original signed by]

J. P. Prince, Ph.D.

Board Member

Attachments

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