Hilcorp applies for Milne disposal wells

Hilcorp Alaska has applied to the Alaska Oil and Gas Conservation Commission for permission to drill four disposal wells from the new Moose pad that the company has been developing in the North Slope Milne Point field. The purpose of the wells is to dispose of produced water from the field by injecting it into the relatively shallow Ugnu formation. The field produces oil from deeper horizons in the Schrader Bluff, Kuparuk and Ivishak.

Hilcorp told the commission that the proposed wells would enable the disposal of relatively high salinity produced water, so that lower salinity water can be injected into field reservoirs for enhanced oil recovery. The injection of low salinity water rather than more saline water is likely to increase the recovery of oil from the field by about 5 percent, the company said.

Apparently the company obtains low salinity water for enhanced oil recovery use from the Prince Creek formation - the ability to dispose of produced water through underground injection would enable more Prince Creek water to be used, thus improving the oil recovery from the field. The Prince Creek formation lies above the Ugnu and is isolated from the Ugnu by impervious rocks.

The new Moose pad is situated in the far western part of the Milne Point unit. Hilcorp has planned the drilling of 50 to 70 wells from the pad, with drilling expected to start in the fourth quarter of this year and first production anticipated in November. Production should peak at around 16,000 barrels per day in 2020, with an estimated ultimate recovery of 30 million to 50 million barrels.

Water for injection into the proposed disposal wells would come from production wells both on the Moose pad and on other pads in the northwestern part of the unit, Hilcorp told the AOGCC.

- ALAN BAILEY