AOGCC approves PBU injection commingling

Kristen Nelsob

Petroleum News

The Alaska Oil and Gas Conservation Commission has approved applications by Prudhoe Bay unit operator BP Exploration (Alaska) for downhole commingling of injection between the Prudhoe, Aurora and Borealis oil pools, subject to applications by BP for each well prior to the commingled injection.

Aurora and Borealis are oil pools in the Kuparuk formation which overlie the Prudhoe oil pool, the commission said in April 3 decisions. Aurora is present in the drill site S area of the Prudhoe Bay unit. Borealis is present in the drill site L, V and Z areas of the unit.

Both the Aurora and Borealis oil pools are authorized for lean and miscible gas injection as well as water injection for enhanced recovery purposes, the commission said. Commingled injection between the Aurora and Prudhoe oil pools is already authorized in wells PBU S-09 and PBU S-31A; there is currently no commingled injection between the Borealis and Prudhoe oil pools.

Lean and miscible gas used for injection in the three pools is sourced from the PBU Central Gas Facility and Central Compression Plant, and services drill sites L, S and V. The commission said the gas available for injection is the same for both the Prudhoe oil pool and the Kuparuk formation pools, Aurora and Borealis.

The commission said several Prudhoe oil pool wells penetrate the Aurora oil pool “in a location that could be advantageous for providing enhanced recovery injection operations for that pool. Some of these locations have insufficient reserves to justify a standalone injection well, so commingling injection with the POP provides an opportunity to enhance recovery that otherwise would not be available.”

The commission said the same thing about the Borealis oil pool - several Prudhoe wells penetrate the Borealis “in a location that could be advantageous for providing enhanced recovery injection operations for that pool,” and some of the locations “have insufficient reserves to justify a standalone injection well.”

- KRISTEN NELSON