Independents' exploratory wells probe San Joaquin's deep potential

G. Alan Petzet
Exploration Editor

Two wells, one a spectacular blowout that has outlasted eight surface kill attempts, are enhancing perceptions of deep potential in California's San Joaquin basin.

Neither well is yet completed, and revenues from hydrocarbons sold from the one that blew out are being placed in escrow. The wells, both drilled below 15,000 ft, lie about 35 miles apart in a province where the well depth averages about 2,000 ft.

Nuevo Energy Co., Houston, operates the Cree Fee lease in 30-31s-22e, about 7 miles south of McKittrick. Nuevo last year re-entered the 1A Cree Fee, which ARCO drilled to 14,452 ft in 1984-85, and deepened it to 17,156 ft.

Testing commenced in early 1999, with several zones as deep as Eocene to be evaluated. The objectives include more than 2,900 ft of fractured Miocene McDonald shales that some consider a target for modern horizontal drilling technology. Nuevo has released no further information.

Deep prospects in this less explored area of the basin, including the area around the Cree Fee well, were the subject of an article in these pages by Glendale geologist and engineer Russell R. Simonson (OGJ, Apr. 29, 1991, p. 69).

Simonson said other operators are now studying deeper potential on their acreage in northwestern Kern County.

East Lost Hills prospect

Meanwhile, the U.S. subsidiary of Elk Point Resources Inc., Calgary, in May 1998 spudded Bellevue 1, in 17-26s-21e, projected to 19,000 ft or the Miocene Temblor formation.

The well blew out and ignited on the evening of Nov. 23, 1998. No injuries were reported (OGJ, Nov. 30, 1998, p. 34). The well was at 17,640 ft and had penetrated about 17 ft of the Temblor formation. Boots and Coots representatives and numerous other specialists reported to the scene. Fire destroyed the Nabors Drilling USA rig (see cover photo).

Initial report was that the produced stream contained light oil, condensate, natural gas, and water. Estimates of the gas flow fell within a wide range until late March, when one of the Canadian participants placed the rate at 16 MMcfd. That could indicate cumulative flow of about 2 bcf of gas since the well blew out, but conclusions may be unreliable due to the condition of the well bore.

Water flow snuffed the flames in early December. The companies spudded a relief well about 1,500 ft away in mid-December, and the well control crews gave up in early February after the eighth surface kill attempt failed.

Liquid hydrocarbons were being collected at the surface. As of mid-March gas was being diverted to power surface facilities at a nearby heavy oil field.

The well was making an estimated 24,000 b/d of water, hauled away for a time by about 150 trucks/day. In March the water was piped 1½ miles away to an approved disposal well.

Mechanical conditions make it necessary for the relief well to intersect the original well bore below 16,000 ft. The downhole kill effort could come this month or in May.

The initial drilling reached about 17,000 ft, where dipmeters showed the well bore had missed the structure. The operator plugged back to about 11,000 ft and redirected drilling from that point. The discovery well bore is insured but is not believed salvageable.

A multicompany group led by Berkley Petroleum Corp., Calgary, intended to spud three more Temblor wells in sequence on the block, with the first well to start soon. Elk Point is a participant in the new drilling and remains operator of the Bellevue relief and discovery wells.

Armstrong Resources LLC, Denver, and PYR Energy Corp., Denver, generated the prospect in the late 1990s on a farmout from Chevron Corp. and sold it to a group of mainly Canadian independents. PYR, which owns a carried interest in the well, is a young public company with no reserves or production.

The apparent discovery is on a structure 12½ miles long by 2 miles wide with as much as 2,000 ft of relief. The participants hold leases or options on about 30,000 acres in the area.

Working interests are Berkley 46%, Paramount Resources Ltd. 25%, Westminster Resources 9%, Hilton Petroleum Ltd. (which is merging with Stanford Oil & Gas Ltd., 7%, Bellevue Resources (Elk Point) 5%, and North Arm Resource Inc. and Trimark Resources Ltd. (Hilton affiliate) each 4%.