Discovery and Development of Sawtelle Oil Field: ABSTRACT

Abstract

The Sawtelle oil field, discovered by Occidental Petroleum Corporation in 1965, is the westernmost of nine producing fields along a 15-mi trend of anticlinal oil accumulations distributed en echelon along the northerly margin of the Los Angeles basin. Wells at Sawtelle confirm that the normal stratigraphic section has been disordered by approximately 7,000 ft of apparent vertical displacement along the northerly trending Santa Monica thrust fault zone. The mountainous hanging wall block is comprised of a thin veneer of recent sediments; nonproductive lower Pliocene and upper Miocene sandstone and shale; middle Miocene sandstone, shale, and volcanic rocks; and Mesozoic Santa Monica Slate. Beneath the fault zone, within the basinal footwall block, are lower Pliocene sandstones and shales, oil-bearing upper Miocene sandstone and shales, and middle Miocene sandstones and shales. Production has been established in two pools: on the south in the upper Miocene Rancho sands within an asymmetric southeast-trending anticline where net pay exceeds 500 ft, and on the north where these same sands appear even thicker within the south limb remnant of a parallel anticline which has been End_Page 432------------------------------ dragged upward and overturned along the hanging wall block of the Santa Monica fault zone. Thirteen wells have been completed beneath the Federal lands of the Sawtelle Veterans Hospital and an adjacent town-lot area on the north. Production through 1971 totals 6,470,000 bbl of oil and 5,790 MMcf of gas. Current production is 2,000 bbl of oil per day and 2,600 Mcf of gas per day. Average vertical depth to the top of the zone is 9,500 ft; initial pressures were hydrostatic. Porosity averages 18% and permeability averages 20 md. Connate water averages 27%; and oil gravity ranges from 18 to 26° API. Minor exploration potential remains, but drilling costs are considered too high to justify additional work, and development is therefore considered complete. End_of_Article - Last_Page 433------------