Joint Meeting Pacific Section, AAPG & Cordilleran Section GSA April 29–May 1, 2005, San José, California
Evaluation of the Stranded Kavik Gas Field, North Slope of Alaska
Mahendra K. Verma1, Kenneth J. Bird2, Philip H. Nelson1, and Robert C. Burruss3
1 Geology, U.S. Geol Survey, P.O. Box 25046, MS 939, Denver Federal Center, Denver, CO 80225, [email protected]
2 Geology, U.S. Geol Survey, 345 Middlefield Road, MS 969, Menlo Park, CA 94025
3 Geology, U.S. Geol Survey, 12201 Sunrise Valley Drive, MS 956 National Center, Reston, VA 20192
The Kavik gas field, located about 60 miles southeast of Prudhoe Bay in the Brooks Range foothills, was discovered in 1969 on a thrust-faulted anticline representing the western, down-plunge extension of the Sadlerochit Mountains. Although this field is one of the larger and better-defined foothills gas accumulations, for lack of a North Slope gas transportation system this field has not been developed and no public estimate of gas volume has been previously made.
Three wells delineate the field, but only two penetrate the gas column that is about 1,500 ft thick. Based on the gas pressure gradient from drillstem tests, the gas-water contact is estimated to be at 4,320 ft subsea. At this depth, the field covers about 3,600 acres. The reservoir temperature and initial pressure are estimated as 122°F and 2431 psi, respectively, at the datum of 3500 ft subsea. Analyses indicate that the gas is dry, contains about 96% methane, and has a combined nitrogen and carbon dioxide content of 3%; gas-liquid ratio ranges from 0.3 to 1.3 barrels per million cubic feet of gas.
Kavik reservoirs, in decreasing order of importance, include the Ledge Sandstone Member of the Ivishak Formation, Sag River Sandstone, and Shublik Formation, all of Triassic age. Gas-in-place volume has been calculated at 165 billion standard cubic feet (BSCF). Assuming a 70% recovery factor, the Kavik field is estimated to have 115 BSCF of technically recoverable gas.
The median value of open-flow capacity of tested Kavik wells is 11.9 million standard cubic feet per day (SCF/D). Based on an average production rate of 4-8 million SCF/D per well, the field could potentially be developed to produce at a rate of 20 million SCF/D, resulting in a field life of about 16 years.
Posted with permission of The Geological Society of America; abstract also online (http://gsa.confex.com/gsa/2005CD/finalprogram/abstract_84464.htm). © Copyright 2005 The Geological Society of America (GSA).