Central Wilmington pipeline ends oil trucking

Oil production is increasing and trucking oil has been eliminated from the central part of Wilmington field in Long Beach, Calif.

A new 10-in., 20,000 b/d oil pipeline placed in service Mar. 14 now transports crude to the ConocoPhillips refinery at Carson, just north of Wilmington field. The pipeline eliminates 50 trips/day by tanker trucks, said Warren Resources Inc., New York, which operates the Wilmington Townlot and North Wilmington units.

The company’s two units are in the central part of giant Wilmington field, an 18½-mile long structure that ranks as the third largest oil field in the US in terms of cumulative production after Prudhoe Bay in Alaska and East Texas field.

Production from the two units averaged 3,500-3,700 b/d in mid-June. The units produced 243,000 bbl in the quarter ended Mar. 31, up 51% on the year. The company had booked 34 million bbl of net proved reserves in WTU and 19 million bbl in NWU at the end of 2007. The figures for WTU don’t include further secondary recovery or alkaline-surfactant-polymer flood potential. Warren Resources has also taken steps to consume more associated gas and may eventually be able to sell gas from the units.

Oil operations

The WTU was producing 375 b/d when Warren assumed operation in 2005.

The City of Los Angeles in 2006 approved the drilling of as many 540 directional oil and water injection wells from as many as five cellars in the WTU (see map, OGJ, Feb. 19, 2007, p. 36). Warren Resources has completed construction of two cellars on one city block in Long Beach, and about 100 wells are producing.

The 2008 capital budget for the WTU is $42 million to drill or recomplete 30 producing wells and six water injection wells and $16 million for cellar construction and other facilities improvements.

A soundproofed electric rig is to replace the unit’s conventional rig in the third quarter of 2008. The cellars allow drilling to take place below ground surface. Most of the newer wells will be horizontal or high angle penetrations.

The company drilled three producing and four injection wells in the first quarter to the Upper Terminal reservoir at 3,600 ft. Recoverable oil also remains in the shallower Tar and Ranger formations, and one of the wells helped confirm the company’s expectation of a meaningful oil resource in the Tar formation, said Ken Gobble, chief operating officer.

Warren Resources has identified 10 more Tar well locations, but it deferred drilling the higher-rate Tar horizontal wells in the first quarter due to oil and gas handling constraints.

Ultimately the company plans to evaluate the deeper Union Pacific, Ford, and basement Schist formations. Another $17 million is budgeted for the NWU, where 55 wells are producing.

Gas potential

Warren Resources is also making greater use of gas from the WTU.

The company has a permit to flare as much as 93 Mcfd from the unit, and in October 2007 it began operating six microturbines that convert part of the produced gas to electricity for field use.

The company also applied to the South Coast Air Quality Management District for a permit to install a high-efficiency, low-emission enclosed burner to replace the existing flare. The microturbines will burn 140 Mcfd, and field heater-treaters take 25 Mcfd.

Even though the current gas-oil ratio is very low, continued Upper Terminal and Ranger waterflood development will boost gas output, and the company is applying for short-term reinjection permits, Gobble said.

Terminal/Ranger drilling and future development of the deeper Ford formation, if successful, could eventually boost gas volumes to salable levels. The field’s underexplored basement Schist zone also contains oil and gas.