ABSTRACT: A Western Thalweg of the Princeton Valley Submarine Canyon System as a Reservoir and a Trap Near Willows, California

Robert W. Bainer, Richard G. Blake

The Princeton Valley submarine canyon system has long been an important reservoir and trapping mechanism in the northern Sacramento Valley, California. Recently a western thalweg of the system, identified north of Willows, California, has proven to be a significant trapping mechanism for gas in truncated Kione Formation sandstones.

Both Upper Cretaceous Kione Formation and Paleocene Princeton Valley sandstones are exploratory objectives in the area and are productive in existing wells.

The Kione Formation, a sand-rich deltaic sequence approximately 2000 ft thick, has been truncated to the west by the Princeton Valley submarine canyon system. The canyon (gorge) has been subsequently filled with primarily impermeable shales, providing a trap for migrating gases in the truncated sands.

The trend was discovered in 1977 by Shell Oil Company based on seismic and was the first substantiated evidence of a western thalweg of the Princeton Gorge in the Willows area. To date, four wells have been completed along the trend and current exploratory efforts are attempting to follow the gorge trend.

AAPG Search and Discovery Article #91003©1990 AAPG Annual Convention, San Francisco, California, June 3-6, 1990