AOGCC approves Hilcorp request to define new pool at Kenai field

The Alaska Oil and Gas Conservation Commission has approved a request from Hilcorp Alaska to approve the specification of a new gas pool in the Kenai gas field and to allow the comingling of gas from that pool with gas from two other pools in the field during gas production. The company told the commission that it wants to drill five new wells into the new pool but that, if an individual well cannot produce gas from pools additional to the new pool, the drilling of the well may not be viable.

Because each gas pool may have different ownership rights, Hilcorp plans to allocate gas production between the comingled sources by running regular production logs, measuring relative production from the different pools.

The Kenai gas field, on the Kenai Peninsula to the south of the town of Kenai, was the first major gas field to go into production in the Cook Inlet basin. The field’s gas reservoirs consist of multiple sand bodies laid down from rivers that flowed in the region during Tertiary times. The field has produced gas from seven distinct pools, with each pool containing multiple sand units. And, because of variations in the characteristics of the rivers that laid down the sands, the nature, and hence the productivity, of the sands can differ between the different pools.

The Sterling formation, the shallowest and youngest of the gas-bearing formations in the field, has been the most productive of the field’s producing formations since the field went into production in 1961. The Sterling has five distinct gas pools, one of which is now used as a gas storage reservoir. A sixth pool, straddling the Beluga formation and the upper part of the Tyonek formation, lies underneath the Sterling and consists of relatively large number of small sand channels. The seventh pool, lower down in the Tyonek, is called the Tyonek Pool 1.

The additional pool that the commission has now approved lies in the Tyonek formation, below Tyonek Pool 1, and is called the Kenai Deep Pool. Hilcorp asked to be allowed to comingle gas from the Kenai Deep Pool, the Tyonek Pool 1 and the Beluga/Upper Tyonek pool in its new wells.

Although the production performance from the new pool is likely to be broadly similar to that of the shallower Beluga/Upper Tyonek pools above it, different individual sands are likely to exhibit different production characteristics - allowing the comingling of gas from the three gas pools will improve resource recovery and prevent waste, the commission wrote in approving Hilcorp’s comingling request.

- Alan Bailey