Reservoir Characterization of a Fan-Shaped Turbidite Complex in an Active-Margin Basin, Miocene Stevens Sandstone, Yowlumne Field, San Joaquin Basin, California

Yowlumne is a giant oil field, in the San Joaquin basin of Califomia, that has produced over 16.7 million m³ (105 million bbl) of oil from Upper Miocene, deep-water sandstones known as the "Stevens" (Figure 1). These sandstones, which represent clastic facies of organic-rich shales in the Monterey Formation (Figure 2), are some of the most prolific reservoirs in the basin and have contributed about 15% of over 1.9 billion m³ (12 billion bbl) of oil produced here since 1864. An integrated reservoir analysis enabled cost-effective exploitation of the distal margin of a layered, low-permeability, fan-shaped turbidite complex contained within the Yowlumne Stevens.