STATE OF ALASKA

ALASKA OIL AND GAS CONSERVATION COMMISSION

3001 Porcupine Drive

Anchorage, Alaska 99501-3192

Re: THE REQUEST OF UNION ) Area Injection Order No. 5
OIL COMPANY OF CALIFORNIA )
for an Area Injection Order ) Trading Bay Unit
for the Trading Bay Unit ) McArthur River Field
July 25, 1986

IT APPEARING THAT:

1. Union Oil Company of California (Unocal) requested the Alaska Oil and Gas Conservation Commission to issue an Area Injection Order permitting the underground injection of fluids within the Trading Bay Unit for purposes of enhanced hydrocarbon recovery.

2. Notice of an opportunity for a public hearing on July 24, 1986, was published in the Anchorage Times on June 24, 1986.

3. Neither a protest nor a request for a public hearing was timely filed. Accordingly the Commission will, in its discretion, issue an order without a public hearing.

FINDINGS:

1. An order permitting the underground injection of fluids on an area basis, rather than for each injection well individually, provides for efficiencies in the administration and surveillance of underground fluid injection operations. 20 AAC 25.460 provides the Commission with the authority to issue an order governing under ground injection operations on an area basis.

2. The Trading Bay Unit (TBU) boundary encompasses the entire McArthur River Middle Kenai "G" Oil Pool; the entire McArthur River Hemlock Oil Pool; and the entire McArthur River West Foreland Oil Pool.

3. All existing injection wells and injection well sites planned for enhanced recovery of oil from these three pools lie within the Trading Bay Unit boundary. Union Oil Company of California is the sole unit operator.

4. The portion of aquifers beneath Cook Inlet described by a 1/4 mile area beyond and lying directly below the Trading Bay Unit are exempted for Class II injection activities by 40 CFR 147.102(b)(2)(B) and 20 AAC 25.440(c).

5. Less stringent requirements for well construction, operation, monitoring and reporting of injection operations may be more appropriate than would be required when injection occurs into, through or above portions of aquifers not exempted.

6. The vertical limit of injection strata and confining formations for the Middle Kenai "G" Oil Pool and the West Forelands Oil Pool may be defined in the Unocal TBU Well No. G-7 and for the Hemlock Oil Pool in Unocal Grayling Well No. 1A.

7. The strata into which fluids are to be injected will accept fluids at injection pressures which are less than the fracture pressure of the injection strata and their confining formations.

8. Statewide regulations and conservation orders govern field operations except as modified by this order.

9. To ensure that fluids injected are confined to injection Strata, the mechanical integrity of injection wells should be demonstrated periodically and monitored routinely for disclosure of possible abnormalities in operating conditions.

10. Injection wells existing on the date of this order were onstructed and completed in accordance with regulations which conform to the requirement of 20 AAC 25.412.

NOW, THEREFORE, IT IS ORDERED THAT the rules hereinafter set forth govern Class II underground Injection operations in the following described area referred to in this order as the affected area:

SEWARD MERIDIAN

T9N R13W Section 8: SE 1/4 SW 1/4, S 1/2 SE 1/4.
Section 9: S 1/2 SW 1/4, S 1/2 SE 1/4.
Section 10: S 1/2 SW 1/4, S 1/2 SE 1/4.
Section 11: SW 1/4 SW 1/4.
Section 14: S 1/2 SW 1/4, NW 1/4 SW 1/4, W 1/2 NW 1/4, SW 1/4 SE 1/4.
Sections 15 and 16.
Section 17: E 1/2, SW 1/4, E 1/2 NW 1/4, SW 1/4 NW 1/4.
Section 18: S 1/2 NE 1/4, SE 1/4, E 1/2 SW 1/4, SW 1/4 SW 1/4, SE 1/4 NW 1/4.
Sections 19, 20, 21 and 22.
Section 23: W 1/2 E1/2, W 1/2.
Section 26: W 1/2 E1/2, W 1/2.
Sections 27, 28, 29, 30, 31, 32, 33 and 34.
Section 35: W 1/2 NW 1/4, NE 1/4 NW 1/4, W 1/2 SW 1/4, NW 1/4 NE 1/4.
T9N R14W Section 13: SE 1/4 SE 1/4.
Section 24: NE 1/4 NE 1/4, S 1/2 NE 1/4, SE 1/4, E 1/2 SW 1/4, SE 1/4 NW 1/4.
Section 25: E 1/2, E 1/2 W 1/2.
Section 36: E 1/2 NW 1/4, NE 1/4, N 1/2 SE 1/4, SE 1/4 SE 1/4, NE 1/4 SW 1/4.
T8N R13W Section 3: N 1/2 NW 1/4, SW 1/4 NW 1/4, W 1/2 SW 1/4.
Sections 4, 5, 6, 7 and 8.
Section 9: W 1/2, W 1/2 E 1/2, NE 1/4 NE 1/4.
Section 10: NW 1/4, NW 1/4.
Section 16: NW 1/4, W 1/2 NE 1/4, NW 1/4 SE 1/4, N 1/2 SW 1/4, SW 1/4 SW 1/4.
Section 17 and 18.
Section 19: N 1/2, SE 1/4, E 1/2 SW 1/4, NW 1/4 SW 1/4.
Section 20: N 1/2, N 1/2 SE 1/4, SW 1/4 SE 1/4, SW 1/4.
Section 21: NW 1/4 SW 1/4, W 1/2 NW 1/4.
Section 29: N 1/2 NW 1/4, NW 1/4, NE 1/4.
Section 30: N 1/2 NE 1/4, NE 1/4 NW 1/4.
T8N R14W Section 1: E 1/2, E 1/2 W 1/2, NE 1/4 NW 1/4.
Section 12: E 1/2, E 1/2 W 1/2.
Section 13: E 1/2 E 1/2, NW 1/4 NE 1/4, NE 1/4 NW 1/4.
Section 24: E 1/2 NE 1/4, NE 1/4 SE 1/4.

Rule 1 Authorized Injection Strata for Enhanced Recovery

Within the affected area, non-hazardous fluids may be injected for purposes of pressure maintenance and enhanced oil recovery into strata defined as those strata which correlate with the strata found in the Unocal Grayling Well No. 1A between the measured depths of 9,372 feet and 9,897 feet and which correlate with the strata found in the Unocal TBU Well No. G-7 between the measured depths of 9,116 feet and 9,695 feet and between 10,208 feet and 11,208 feet.

Rule 2 Fluid Injection Wells

The underground injection of fluids must be: 1) through a new well that has been permitted for drilling as a service well for injection in conformance with 20 AAC 25.005; 2) through an existing well that has been approved for conversion to a service well for injection in conformance with 20 AAC 25.280; or 3) through a well that existed as a service well for injection purposes on the date of this order.

Rule 3 Monitoring the Tubing/Casing Annulus Pressures

The tubing/casing annulus pressure of each injection well must be routinely checked weekly to ensure there is no leakage and that it does not exceed a pressure that will subject the casing to a hoop stress greater than 70% of the casing's minimum yield strength.

Rule 4 Reporting the Tubing/Casing Annulus Pressure Variations

Tubing/casing annulus pressure variations between consecutive observations need not be reported to the Commission.

Rule 5 Demonstration of Tubing/Casing Annulus Mechanical Integrity

A schedule must be developed and coordinated with the Commission which ensures that the tubing/casing annulus for each injection well is pressure tested prior to initiating injection and at least once every four years thereafter. A test surface pressure of 1500 psi or 0.25 psi/ft multiplied by the vertical depth of the packer, which ever is greater, but not to exceed a hoop stress greater than 70% of the casing's minimum yield strength, must be held for 30 minutes with no more than a 10 percent decline. The Commission must be notified at least 24 hours in advance to enable a representative to witness pressure tests.

Rule 6 Well Integrity Failure

Whenever operating pressure observations or pressure tests indicate pressure communication or leakage of any casing, tubing or packer, the operator must immediately cease injection, notify the Commission, and obtain approval for corrective action.

Rule 7 Plugging and Abandonment of Fluid Injection Wells

An injection well located within the affected area must not be plugged or abandoned unless approved by the Commission in accordance with 20 AAC 25.105.

Rule 8 West Forelands Enhanced Recovery

Fluid injection into strata which correlate with the strata found in Unocal TBU Well G-7 between the measured depths of 10,208 feet and 11,208 feet must not be undertaken prior to obtaining Commission approval to conduct enhanced recovery operations for the West Forelands Oil Pool.

Rule 9 Administrative Relief

Upon request, the Commission may administratively amend any rule stated above as long as the operator demonstrates to the Cmmission's satisfaction that sound engineering practices are maintained and the amendment will not result in an increase risk of fluid movement into an underground source of drinking water.

DONE at Anchorage, Alaska and dated July 25, 1986.

C V. Chatterton, Chairman
Alaska Oil and Gas Conservation Commission

Lonnie C. Smith, Commissioner
Alaska Oil and Gas Conservation Commission

W. W. Barnwell Commissioner
Alaska Oil and Gas Conservation Commission

Area injection Order Index