Development Geology of the Antelope Shale: Section 1Y, Cymric Field, San Joaquin Valley, California - The Antelope Shale reservoir in Section 1Y, Cymric Field, San Joaquin Valley, California is one of Chevron’s key assets. The reservoir is a Miocene Age member of the Monterey Formation composed of Opal A (amorphous), Opal CT (cristobalite, tridimite) and Quartz phase diatomaceous deep water... » More

Development Geology of the Antelope Shale: Section 1Y, Cymric Field, San Joaquin Valley, California - The Antelope Shale reservoir in Section 1Y, Cymric Field, San Joaquin Valley, California is one of Chevron’s key assets. The reservoir is a Miocene Age member of the Monterey Formation composed of Opal A (amorphous), Opal CT (cristobalite, tridimite) and Quartz phase diatomaceous deep water sediments. The Antelope Shale has an anomalously high average porosity of 58%, high initial oil saturations of up to 60%, and low permeabilities of 3 millidarcys. Development geology skills required to process this complex reservoir and involve: obtaining, analyzing, and evaluating open hole well logs; structural mapping and correlation; fracture mapping using development geophysics; and an understanding of the diagenetic process.; J. Fred Bair, MWSS Asset Development Team, Chevron North America Exploration and Production Company « Hide