Buccaneer Energy Ltd. recently finished drilling the Cosmo No. 1 well and now plans to test a relatively shallow oil discovery at the Cook Inlet prospect, the company said July 16.
The local subsidiary of the Australian independent said it has drilled the offshore well to a total depth of 7,599 feet, slightly shallower than its initial target of 8,000 feet. Now, Buccaneer plans to install a 7-inch liner in the well to accommodate a production test of an oil discovery at the base of the Tyonek formation, according to the company.
Buccaneer said it collected 60 sidewall core samples, six hydrocarbon samples (one gas and five oil) and 27 pressure results using a Modular Formation Dynamics Tester.
As previously announced, Cosmo No. 1 encountered oil-bearing sands in the Lower Tyonek, some 400 feet shallower than the oil shows in previous Cosmopolitan wells. All told, according to Buccaneer, Cosmo No. 1 encountered some 488 feet of “indicated oil and gas pay,” including 18 gas zone and eight oil zones, in the Tyonek formation.
The well also found oil in the Starichkof and Hemlock formations, where previous Cosmopolitan wells discovered hydrocarbons. Cosmo No. 1 found 43 feet of indicated oil pay in the Starichkof and 149 feet of indicated oil pay in the Hemlock, according to the company. “Not all of the zones intersected will be flow tested,” Buccaneer said.
Buccaneer is the operator of the Cosmopolitan prospect and holds a 25 percent working interest in the leases there, with BlueCrest Energy Inc. holding the majority stake.
The prospect is in the southern Kenai Peninsula, off the coast of Anchor Point.
Fourth attemptCosmopolitan is a legacy discovery left undeveloped because of geology and economics.
Pennzoil discovered the prospect in 1967 with the Starichkof State No. 1 and the Starichkof State Unit No. 1, but the results did not justify development at the time.
ConocoPhillips formed the Cosmopolitan unit in 2001. The following year it drilled the Hansen No. 1 well up dip of Starichkof State No. 1, encountering oil in the Starichkof and Hemlock intervals. ConocoPhillips drilled the Hansen 1A sidetrack in 2003, and a 50-day flow test averaged 550 barrels per day of oil. The company shot a 3-D seismic survey over the unit in 2005, but also ultimately chose not to development the prospect.
Pioneer Natural Resources Alaska subsequently acquired Cosmopolitan. In 2007, the company drilled Hansen 1A-L1, a lateral from the Hansen 1A wellbore targeting the upper Starichkof interval. Pioneer re-entered and flow tested the lateral in early 2010.
In a plan of operations around that time, Pioneer described the reservoir as being “lower quality than most other producing oil fields of the Upper Cook Inlet.” Still the company launched a unique pilot project to truck crude oil from Cosmopolitan flow tests to the Tesoro refinery in Nikiski. The field produced 33,504 barrels of oil and 119,006 thousand cubic feet of gas, according to Alaska Oil and Gas Conservation Commission figures.
Even though it proposed plans to expand production, Pioneer went the way of Pennzoil and ConocoPhillips in early 2011, saying, “subsequent flow test results and engineering studies indicated that the resource potential was not as large as originally estimated.”
The departure split the unit in two. Much of the acreage returned to the state to be offered up in a special lease sale, but Pioneer sold two leases to Buccaneer and BlueCrest.
Cosmo No. 1 is the first well drilled in Alaska using the Endeavour jack-up rig. Buccaneer owns the rig through its joint venture Kenai Offshore Drilling LLC. The Alaska Industrial Development and Export Authority helped the joint venture purchase the jack-up rig.
Buccaneer believes the rig will improve the economics of Cosmopolitan by keeping the company from having to drill all its wells from an onshore pad, the company has said.
The Endeavour rig will move next to the Buccaneer-operated Southern Cross unit.