We investigate the impact of decades of oil production at the Wilmington oil field, located in the Los Angeles basin, CA, on the stability of the Wilmington thrust fault system. We do so using coupled flow and geomechanics modeling and publicly available production information from 1936 to present day.

We use literature information to build a detailed geological model of the Wilmington oil field. Our geological model includes the main stratigraphic intervals reported in the literature, the upper Miocene and Pliocene horizons, as well as the top of the basement. Additionally, we use literature-reported cross-sections and available 3D seismic data to map several normal faults that intersect the Wilmington anticline. These faults exert important hydraulic control over the pore pressure and subsidence distribution at the Wilmington oil field. Our structural model also includes two main regional faults: the Wilmington blind-thrust fault and the strike-slip Newport-Ingleewood fault. Current work is underway to build an unstructured mesh that conforms to all horizons and faults and that will serve as the basis for our coupled flow and geomechanics simulations.

We first process and analyze the historical production information of the Wilmington oil field. There are several wells in the historical production database that do not have bottom-hole well coordinates. We therefore design a cross-correlation method to estimate the well coordinates based on its production and the production information of other wells in the field that have well coordinates. We assess our updated well coordinates by analyzing the consistency of the spatiotemporal evolution of fluid production/injection in the field. We also gathered and compiled publicly available reservoir pressure information available at the California Department of Conservation. Initial reservoir simulations were performed using homogenous reservoir properties and initial results show that reservoir pressure decrease significantly during the early periods of production in the field (from 1936 to 1950), a result that is in agreement with the notion that reservoir pressure depletion caused reservoir compaction and significant ground subsidence during first 20 years of production in the field.

Please contact the author (jsilva.mit@gmail.com) if you are interested in slides from this presentation-- file size was too large to attach here.