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The AAPG/Datapages Combined Publications Database

AAPG Bulletin


Volume: 28 (1944)

Issue: 12. (December)

First Page: 1777

Last Page: 1778

Title: Kettleman Hills North Dome: ABSTRACT

Author(s): Martin Van Couvering

Article Type: Meeting abstract


Kettleman Hills North Dome oil field, discovered in 1928, occupies a long narrow anticline on the west side of the San Joaquin Valley, California. The oil field is about 15 miles long and 2 miles wide. The crest of the anticline has been eroded, leaving exposures of the underlying formations so obvious that the structure was recognized many years ago. However, inferences about the extent and position of the oil accumulation, prior to the development of the field, were wrong. The history of this field provides an excellent illustration of the growth of geologic knowledge, and is discussed at some length.

Effective January 31, 1931, a unit plan of operation was adopted by the various lessees of Government land in the field. In November, 1932, a map was drawn in an attempt to establish the position of the 7,000-foot subsea structural contour. The position of this contour was agreed on by the member companies and was accepted as defining the probable productive area. Subsequent events have only slightly modified the general opinion about position of the 7,000-foot contour, but the productive area has proved to be substantially different than was originally believed. Development of the field, including the drilling of unproductive outpost wells, has demonstrated that production extends below the 7,100-foot subsea contour on both the northwest plunge and the northeast flank, while on the o posite plunge and flank, it reaches only about the 6,500-foot subsea contour. The latter flank is much the steeper.

What has caused this inclination? Various reasons are suggested, some of which are not original with the author. 1. Remnants of a dissected peneplain suggest a slight warping of the structure after accumulation had occurred following the main folding in middle Pleistocene time. An inference is drawn that cementation of the sands at the oil-water interface had prevented fluid readjustment. 2. Since the southwest flank is steeper than the northeast, the strata on that flank could have been subjected to more compression and

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alteration, and have caused the permeability here to be reduced as compared with the opposite flank. 3. The presence of a much higher hydrostatic head on the mountainward or southwest flank as compared with its valleyward counterpart has also been offered as an explanation. In this connection, it has been argued that the difference in specific gravity of the oil and water is not sufficient, with a 600-foot hydrostatic head, to overcome the obstacles of surface tension, friction, and cementation on the high side of the water table. 4. Capillary-gravity action has also been considered a factor. 5. Finally, it has been suggested that the northeast flank had a much greater drainage area from which to draw its oil supply than did the southwest flank.

The fact that the anticline is en echelon with the adjoining structures at both ends, suggests that the forces causing this condition may have had a longitudinal component that could have tilted the north dome structure northward. Other structural and stratigraphic conditions in the field which might bear on the problem of an inclined water table are discussed; and questions are raised as to how much the genesis and migration of petroleum might be involved in a possible solution of the problem.

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Copyright 1997 American Association of Petroleum Geologists