Ventura Oil Field; An Evolution In Development, Waterflood Practices, And Geological Interpretation

Abstract

The Ventura Oil Field, which produced its billionth barrel of oil in 2012, has a long history that began in 1885 with identification of oil in ground water wells. Early mapping identified a ‘perfect anticline’ structure. With this model in mind an attempt to drill the first oil well was initiated in 1902. Initial drilling attempts were fraught with difficulties due to shallow gas and use of cable drilling tools. Development took off in the 1920's when rotary tools were used for drilling. As drilling campaigns expanded and deeper wells were drilled, micropaleontology data identified 3 major faults and steep asymmetric dips. This explained some inconsistencies in production results. Faults combined with seven stratigraphic productive units, resulted in 13 different ‘pools’ that were produced in the 1940s. Primary development continued into the 1950s with the first water flood being implemented in the early 1960s. Over time additional fault blocks have been identified and increased the number of productive ‘pools’ to > 50. Today, after nine different operators and more than 100 years, the anticline structure is well mapped. Thrust faulting has been identified using electric log correlations and dip and image logs. We used 3D structural interpretation develop a full-field fault framework model that is internally consistent, utilizing a flat-ramp-flat fault geometry that has been subsequently folded. This model is being used for development and surveillance. Our turbidite depositional model is being reviewed with legacy geological interpretations, completions, and production data to better understand net to gross and connectivity/thickness of individual layers. The result is a more thorough understanding of the geology of the field for development planning and an appreciation for the evolving story of the Ventura Oil Field.

AAPG Datapages/Search and Discovery Article #90215 © 2015 Pacific Section AAPG Convention, Oxnard, California, May 3-6, 2015