Zodiac Exploration Inc., Calgary, plans to apply a multistage frac to the Kreyenhagen formation in California’s San Joaquin basin in the third week in November, subject to equipment availability.
The company has successfully drilled a 2,647-ft horizontal wellbore in the Upper Kreyenhagen formation at its 1-10 well in Kings County and set a downhole liner assembly with packers and frac ports in preparation for the job. The lateral is an average vertical depth of 14,551 ft.
Effectively drilling the lateral at these depths and high pressure “is a key first step in proving the potential of the Upper Kreyenhagen formation, which is one of several primary plays identified on our acreage to date,” the company said.
The lateral is placed in the same zone that tested oil in the company’s nearby 4-9 well earlier this year (OGJ Online, July 27, 2011).
Detailed geologic mapping indicates this zone is present on at least 100 net sections of Zodiac acreage. The company has 89,000 net acres in Kings County.
Based on preliminary internal estimates from petrophysical logs and core data, management’s best estimate is that the Upper Kreyenhagen prospective resource amounts to 16 million bbl/sq mile. The estimate represents 10% of the Kreyenhagen formation, which is about 800 ft thick at the 1-10 location.
Several prospective lower zones in the Kreyenhagen have been identified and have not yet been tested. The total thickness of the Kreyenhagen formation ranges from 800 to 1,500 ft throughout the company’s acreage.
Zodiac said it has confirmed its view “that with continued wellbore design refinements, horizontal drilling should have widespread application in the development of the other plays that comprise our portfolio.”