ConocoPhillips and Anadarko Petroleum Corp. said Sept. 10 that they have successfully appraised the 2001 Spark discovery in the National Petroleum Reserve-Alaska on Alaska’s North Slope.
The companies drilled two appraisal wells in the Spark accumulation last winter, the Carbon No. 1 and the Spark No. 4.
The Carbon No. 1 appraisal well, about five miles northwest of the Spark No. 1A discovery well, encountered an Upper Jurassic reservoir, the companies said. An unstimulated well test flowed at a maximum rate of 24 million cubic feet per day of gas and 1,250 barrels per day of condensate. The condensate fluid gravity was 59 degrees API, and the flowing tubing pressure was measured at 905 psi. State records show the well was suspended April 23, 2004, at a true vertical depth of 8,193 feet and a measured depth of 8,196 feet.
The Spark No. 4 well was drilled about three miles northeast of Carbon No. 1 and penetrated a similar hydrocarbon-bearing reservoir interval, but was not tested. That well was plugged and abandoned April 13, 2004, at a true vertical depth of 7,997 feet and a measured depth of 8,005 feet.
The Spark accumulation is adjacent to the 2001 Lookout discovery, which was successfully appraised in 2002. The Lookout No. 2 appraisal well tested at a rate of 4,000 bpd of oil and 8 million cubic feet per day of natural gas after fracture stimulation. The oil and gas also were produced from an Upper Jurassic reservoir interval. The oil had an API gravity of 40 degrees, and a flowing tubing pressure of 1,025 psi.
The companies said technical and commercial evaluation of the Lookout (the proposed CD-6 pad) and Spark (the proposed CD-7 pad) discoveries is already under way as part of the Alpine satellites environmental impact statement. Spark and Lookout are 15 and 24 miles, respectively, southwest of the Alpine oil field.
Ownership in these discoveries and the Alpine oil field are: ConocoPhillips (operator) 78 percent and Anadarko 22 percent.
Discoveries in 2000, 2001
The companies’ original NPR-A discoveries were announced in the spring of 2001, and reflected drilling in 1999-2000 and 2000-01. Five wells and a sidetrack, which targeted the Alpine producing horizon, all encountered oil or gas and condensate: Spark No. 1 and No. 1A, Moose’s Tooth C, Lookout No. 1, Rendezvous A and Rendezvous No. 2. A sixth well, targeting a different interval, was a dry hole.
Kevin Meyers, president of ConocoPhillips Alaska predecessor Phillips Alaska, said in May 2001 that the companies were “confident the discoveries will prove to be of commercial quantities. We believe that the five successful wells have encountered three separate hydrocarbon accumulations.”
The Spark No. 1A well tested 1,550 bpd of liquid hydrocarbons and 26.5 million cubic feet per day of gas. The Rendezvous A well tested at an unstimulated rate of 360 bpd of liquid hydrocarbons and 6.6 million cubic feet per day of natural gas.
