Hilcorp applies to expand Milne AEO

Kristen Nelson

Petroleum News

Hilcorp Alaska has applied to the Alaska Oil and Gas Conservation Commission to expand the affected area for the Milne Point unit Aquifer Exemption Order, AEO 2.

(See map in the online issue PDF)

In its March 21 application Hilcorp said the expansion would cover some 36,852 acres and with the expansion the AEO would cover all leases currently included -- wholly or in part -- within the Milne Point unit, including a quarter mile buffer.

The stratigraphy defining the top and base of the AEO would remain the same as the current AEO 2, 2,000 feet true vertical depth to 4,500 feet TVD for the top and base as in well MPA-01, Hilcorp said.

The company said the basis for the expansion is the same criteria as in the original 1987 AEO 2 application, "that the freshwater contained in the sands do not and will not serve as a source of drinking water now or in the future."

AOGCC said regulations allow the U.S. Environmental Protection Agency and the state "to exempt an aquifer or a portion of an aquifer if it does not currently serve as a source of drinking water, if it will not serve as a source of drinking water in the future, or if it meets other criteria such as the natural presence of hydrocarbon, existing contamination, or elevated dissolved solids concentrations," with an exemption allowing aquifer use for "oil- or gas-related production, injection, or disposal purposes" complying with EPA Safe Drinking Water Act requirements and state regulations.

Hilcorp said there are aquifer exemptions immediately to the west for the Kuparuk River unit and immediately to the south for the Prudhoe Bay unit, exemptions which deemed it economically impractical to extract the freshwater for drinking purposes, which is also the case for the proposed AEO 2 expansion area.

Hilcorp cited two bases for expansion: depth and location of freshwater, between 2,000- and 4,500-feet TVD, make its recovery for drinking water "economically or technologically impractical" and total dissolved solids of more than 3,000 and less than 10,000 mg/l mean it is "not reasonably expected to supply a public water system."

The commission said in a public hearing notice published April 7 that it has tentatively scheduled a public hearing on the request for June 10 at 10 a.m. in its Anchorage offices with audio call in at 907-202-7104 conference ID 862 885 746#, but if no request for a hearing is timely filed, it may issue an order without a hearing. Information on whether the hearing will be held can be obtained after April 28 by calling 907-793-1223.