|
Hansen sidetrack has total depth of almost four miles
Kristen Nelson Petroleum News Editor-in-Chief
The Alaska Oil and Gas Conservation Commission has published completion data on the Hansen 1A, the sidetrack ConocoPhillips Alaska drilled at the Cosmopolitan prospect on the southern Kenai Peninsula. The well was drilled from onshore to a bottomhole under Cook Inlet. The measured depth of the well was 20,789 feet, almost four miles. The true vertical depth was 7,102 feet.
The commission said the well was completed June 13 and classified it as an exploratory well with oil shows.
ConocoPhillips Alaska spokeswoman Dawn Patience told Petroleum News Sept. 16 that the company is evaluating data from the well. The Hansen 1A sidetrack is the second well ConocoPhillips has drilled at Cosmopolitan, a prospect in the lower Cook Inlet offshore north of Anchor Point where Pennzoil Co. found oil and gas in 1967 drilling from a jackup rig. Pennzoil's Starichkof State No. 1, a 12,112 foot vertical hole southeast of the Hansen target, recovered oil including 30 barrels of 20 degree API gravity from a drill stem test at about 6,900 feet and 21 barrels from a drill stem test at about 6,800 feet. Pennzoil reported encountering the top of the Hemlock formation at 6,745 feet.
The Starichkof unit was approved in July 1967 and a second well, the 8,776 foot Starichkof State Unit No. 1, was drilled some two miles from the first well but found water in the Hemlock formation at 7,355 feet and a slight amount of gas around 4,000 feet. The Pennzoil discovery was never developed and the unit lapsed. Area unitized again in 2001 Phillips Alaska Inc. (now ConocoPhillips Alaska) filed a unit application with state and federal agencies in 2001 to unitize seven state leases and two federal leases, some 24,600 acres, proposing wells just northwest of the old Starichkof unit. Phillips did some chemical analysis of the Starichkof oil, which was thought to be low gravity crude, and believes that new drilling will show the actual gravity is significantly higher.
Drilling began at the Hansen No. 1 in October 2001; state and federal officials approved formation of the unit in November. The initial plan of exploration required a well to the lower Tyonek sand interval, correlative to the section seen in the Starichkof State No. 1 well between 6,740 feet and 7,006 feet measured depth.
Approval of the unit required acquisition of 3-D seismic or a sidetrack to the Hansen well. ConocoPhillips is the operator at the Starichkof field at Cosmopolitan, and has a 70 percent working interest. Forest Oil has a 25 percent working interest and Devon Energy holds the remaining 5 percent.
Rick Mott, ConocoPhillips Alaska vice president of exploration and land, told an Anchorage audience in April 2003 that the Hansen sidetrack was being drilled from onshore with extended reach technology and what he called "the largest and most powerful drilling rig in Alaska."
The Hansen No. 1 "went down about a mile and a half and then out underneath the inlet about three miles," Mott said, and was a "world-class accomplishment."
The Hansen No. 1A, the sidetrack, "will go even farther out underneath the inlet." Some details on drilling from Forest ConocoPhillips has been close mouthed about results at Cosmopolitan, but Robert Boswell, then president and CEO of Forest Oil, told an investment symposium in April 2002 that the Hansen No. 1 tested oil in the Hemlock and in the Tyonek formations. He said commercial prospects were being evaluated, along with development possibilities.
Forest Oil said in its second quarter earnings report this summer that the Hansen No. 1A sidetrack was completed with a horizontal section through the Starichkof and Hemlock intervals. Forest said the rig was released after a short test and the well was being prepared for an extended production test.
Forest's new president and CEO, Craig Clark, said in August that the well tested oil from the sidetrack. "The operator will be trucking oil to the refinery during the extended test," he said.
State officials told Petroleum News in August that ConocoPhillips tested the sidetrack for four days and then went to partners for approval for a longer test. The state approved a 90-day extension of testing, through Nov. 30. Results are due to the state Jan. 15.
Editor's note: Kay Cashman contributed to this story.
| 