The thermal and cementation histories of a sandstone petroleum reservoir, Elk Hills, California

摘要: Abstract Liquid hydrocarbon accumulations within the Elk Hills and North Coles Levee oil fields, southern San Joaquin basin, are largely isolated calcite-cemented reservoirs comprised of late Miocene Stevens sandstone. We undertook ion microprobe carbon oxygen isotope ratio measurements on calcite cements to assess both source temperature cementation. By combining thermal history results from 40 Ar / 39 analyses (reported in companion study) with calculated cementation temperatures based our measurements, a model is derived which indicates that carbonate precipitation occurred primarily between 4 6.5 Ma. Conventional isotopic yield more restricted range compositions reflecting averaging properties method. The associated suggest most early were marine or mixture lighter maturing hydrocarbons. Carbonates precipitated recently (and thus at highest temperatures) contain light carbon, interpreted result decomposition kerogen interbedded shales. Based values (