Hilcorp Alaska LLC has asked the Alaska Oil and Gas Conservation Commission for a change in rules for the Ninilchik Beluga/Tyonek gas pool to include deeper intervals it is now testing.
The change would be in the pool definition, which is now from gas-bearing intervals between measured depths of 1,480 feet in the Paxton No. 5 well and 9,600 feet in the Paxton No. 1 well. Hilcorp’s requested change is to gas-bearing intervals between measured depths of 1,555 and 9,035 feet in the Kalotsa No. 3 well.
The Ninilchik unit is on onshore and offshore acreage along the Kenai Peninsula from just north of Clam Gulch to just north of Ninilchik and produces natural gas from onshore pads with bottomhole locations both onshore and offshore.
Chevron USA drilled the discovery well on what is now unit acreage in 1961; numerous additional exploration and delineation wells were drilled before regular production began in 2003. The unit was formed in 2001 and expanded in 2003 to encompass the Falls Creek unit, with Marathon Oil as operator holding 60 percent working interest and Union Oil Company of California holding 40 percent. Hilcorp acquired Union’s interest Jan. 1, 2012, and Marathon’s interest Feb. 2, 2013, at which time Hilcorp became operator.
Paxton No. 8In its application for amended pool rules Hilcorp said it drilled and completed the Paxton No. 8 well in the Ninilchik Beluga/Tyonek gas pool in August 2014. That well was completed to the base of the T142 sand, the company said. Hilcorp said the current pool definition includes gas-bearing intervals from the B8 sand down to the T142 sand. Log analysis from the Paxton No. 8 “indicated the possible presence of gas in the deeper Tyonek gas sands lying below the T142 sand,” the company said, something also indicated by log analysis from offset wells, but none of the sub-T142 sands were ever tested.
Sub-T142 sandsHilcorp said it successfully tested the Kalotsa No. 4 well this August in the T146 sand, which is below the gas pool as currently defined by AOGCC. That well had an initial flow rate of about 500 thousand cubic feet per day between 9,021 feet measured depth and 9,084 feet MD, with results from that well confirming “the presence of economic quantities of gas in the sub-T142 sands.”
Hilcorp said it drilled the Kalotsa No. 3 well this June, a well designed to penetrate and test sub-T142 sands and determine the presence of gas pay and reservoir quality, and in its Aug. 29 pool rules change application the company said it was currently testing sub-T142 sands in various Ninilchik field wells.
Initial results from the Kalotsa No. 4 well suggest the Ninilchik Beluga/Tyonek gas pool extends below depths defined in Conservation Order 701A, with further testing needed.
“In order to delineate and develop the sub-T142 sands, the base of the Ninilchik Beluga/Tyonek Gas Pool requires modification for adequate development,” the company said.
The commission has tentatively scheduled a public hearing on the application for Oct. 25 at 10 a.m.