|
State approves Trading Bay expansion in Cook Inlet Both Hemlock and Grayling Gas Sands participating areas expanded Kristen Nelson Petroleum News Editor-in-Chief
The state of Alaska has approved an expansion of the Trading Bay unit in Cook Inlet and expansion of both the unit's Hemlock oil pool participating area and its Grayling sands participating area.
The Department of Natural Resources' Division of Oil and Gas approved the application from Trading Bay unit operator Union Oil Company of California June 25. Unocal applied to expand the Trading Bay unit and Hemlock participating area last November and in December, applied for expansion of the Grayling gas sands participating area. Unocal also applied for an alternate allocation formula for the Grayling participating area.
The unit and Hemlock participating area expansion includes 560 acres of submerged lands in two segments at the northern edge of the unit. This expansion area is in lease ADL 18731. The Grayling gas sands participating area expansion, 3,200 acres, is within the unit.
In addition to Unocal, Forest Oil and Marathon Oil also have working interests in the Trading Bay unit.
The unit includes four participating areas: the Hemlock oil pool participating area, the West Foreland oil pool participating area, the Middle Kenai “G” oil pool participating area and the Grayling gas sands participating area.
The expanded Trading Bay unit and Hemlock participating area encompass 17,859.5 acres within 11 oil and gas leases. The expanded Graying participating area includes 6,520 acres within four oil and gas leases. Monopod well expands production In addition to four platforms within the unit, Unocal also operates the Monopod platform on non-unitized lease ADL 18731 north of the unit. Oil and gas from the Trading Bay unit is also produced from the Monopod and in 2002, the state said, Unocal drilled several sidetracks of the A-15 well from the Monopod. One of those sidetracks extended south into lease ADL 18772 within the unit, producing oil from the Hemlock reservoir both inside and outside of the existing unit boundary.
The division approved allocation of production between leases in 2002, but also required Unocal to apply to expand the unit and the participating area to include the portion of ADL 18731 producing from the Hemlock reservoir. The division also recognized that in 1991 the Alaska Oil and Gas Conservation Commission approved an expansion of the Middle Kenai gas pool, which encompasses the Grayling gas sands, and requested that Unocal apply to expand the Grayling participating area with a request of allocate gas produced on the volume of gas underlying each tract instead of on a surface-acreage basis. Gas pool area expanded in 1990 Grayling participating gas is produced from the Steelhead platform, one of the four platforms in the Trading Bay unit, and after additional wells were drilled in 1990 to test the extent of the Grayling gas sands reservoir, the commission approved an expansion of the Middle Kenai Gas pool area. In 1991, the working interest owners began allocating production to the larger area.
The division said Unocal's recent delineation activity included using new 3-D seismic, engineering and log analysis to re-examine the area north of the Trading Bay unit; two wells established oil production outside of the unit boundary, the Trading Bay Unit No. A27RD, drilled in 1997, and the Trading Bay Unit No. A-15RD2L2, drilled in 2002. That well produced at initial gas-lift test rates of more than 3,000 barrels of oil per day.
Unocal's 39th plan of development for the Trading Bay unit includes optimizing oil recovery from the Hemlock, Middle Kenai and West Foreland participating areas within completed wells and studying potential workover or redrill opportunities. The division said Unocal is also considering rig projects on the Steelhead and Grayling platforms to improve deliverability and recovery of gas reserves from the Grayling participating area and will “continue to evaluate the possibility that oil reservoirs exist within the Jurassic section within” the unit.
| 