The Wilmington oil field, located 20 miles south of Los Angeles and adjacent to the Los Angeles Harbor, is one of the largest oil fields discovered in California.

Oil was first produced in January, 1932, from the Lower Pliocene formation. The General Petroleum Corporation's Terminal No. 1 was the first large well and was completed in December, 1936, with an initial production of 1,500 barrels per day, 20.5° A.P.I. gravity, from the Puente formation (Upper Miocene) at a depth of 3,625 feet.

Discovery was made by correlation of outpost wells together with a seismograph survey which added materially to the general outline of the structure.

The structure is an irregular-shaped dome with faulting transverse to the principal axial trend. The dip of strata ranges from 2° to 15°.

The major faulting apparently occurred near the close of Miocene time and continued progressively throughout deposition of the Repetto formation (Lower Pliocene).

Production is obtained from the Repetto formation (Lower Pliocene) and the Puente formation (Upper Miocene).

There are five producing zones: Tar, Ranger, upper Terminal, lower Terminal, and Ford.

The gravity of oil ranges from 12° to 31°. The lower 700-800 feet of Pliocene and 2,500 feet of Miocene formation contain oil and gas at different stratigraphic levels.

The field has produced a total of 17,608,495 barrels of crude oil from discovery date, December 7, 1936, to February 15, 1938, inclusive.

Recent development in the City of Long Beach has increased the proved area from 2,100 acres to 3,200 acres.

Production on March 2, 1938, was 101,382 barrels daily from 374 wells with a large part of proved area undeveloped.