The latest horizontal well completed in Elk Hills field is bidding to open a new chapter in horizontal drilling in the billion-barrel field.
The well is the first horizontal well targeting the shallow oil zone. Previous horizontal wells tapped the Miocene Stevens sand with good results.
The U.S. Department of Energy with Bechtel Petroleum Operations as contract operator completed 2711-110 well, in 11-31s-24e, Kern County, on the pump for 350 b/d of oil, 1 b/d of water, and 4 Mcfd of gas.
Production compares with the 40-100 b/d of oil produced by offsetting vertical wells.
The well, one of the lowest structurally on the field's southeast flank, went to TD 5,648 measured depth, bottoming about 1/2 mile southwest of the surface location at 2,992 ft true vertical depth.
Production is from a total of 240 ft of perforations in intervals at 5,210-5,325 ft and 5,355-5,420 ft. Behind pipe in the 678 ft section of hole between the casing shoe and the top of presently perforated intervals are more oil sand intervals that will be perforated later.
The horizontal well targeted sub-layers of the SS-1, one of 25 sand layers in the shallow oil zone. Given present production, the well figures to be the forerunner of more shallow oil zone horizontal wells, adding to the reserves by tapping oil that cannot be produced economically by vertical wells.
While the well is the first horizontal well for the shallow oil zone, 10 vertical wells also were completed in the zone in 1995, helping to boost production from 14,900 b/d at the beginning of the year to the present 15,700 b/d.
Until now, the horizontal drilling program at Elk Hills has focused on the 26R Stevens pool in the central portion of the field, where 17 out of 17 wells have been completed since the program began in 1988. Before the 17th completion, the first 16 wells as the 1995 fourth quarter ended were producing 8,740 b/d of oil, or an average of 546 b/d per well. The per-well average is the highest for any onshore field in California and topped by only four offshore fields on federal leases. Production from the 16 wells since the first was completed totals more than 9 million bbl of oil.
The recently completed 17th well is No. 332H-36R, with a TD of 9,712 ft bottoming 2,550 ft southwest of the surface location at 7,350 ft TVD. Present production is 630 b/d of oil and 400 Mcfd of gas.
The 18th horizontal well for the 26R Stevens pool is in completion stage. The well is No. 382AH-27R, which bottomed at 9,842 ft some 2,900 ft southwest of the surface location. A 19th horizontal well for the 26R Stevens was in progress in mid-January, aiming for a total drilled depth of 10,529 ft with TVD of 7,334 ft.
More Stevens zone horizontal wells are planned, pending approval of this year's budget.
Copyright 1996 Oil & Gas Journal. All Rights Reserved.
