Potential for Carbon Dioxide Sequestration and Enhanced Oil Recovery in the Vedder Formation, Greeley Field, San Joaquin Valley, California.

Abstract:

Most scientists agree that greenhouse gases (GHG) such as carbon dioxide (CO₂), Methane (CH₄), and nitrous oxide (N₂O) are major contributors to the global warming trend and climate change. One effort to mitigate anthropogenic sourced CO₂ is through carbon capture and sequestration. Depleted oil and gas reservoirs due to their known trapping capability, in-place infrastructure, and proximity to carbon emission sources are good candidates for possible CO₂ storage. The Vedder formation is one of three reservoirs identified in the San Joaquin Basin that meets standards for possible storage. An analysis of net fluid production data (produced minus injected) from discovery to the present is used to determine the reservoir volume available for CO₂ storage. Data regarding reservoir pressure response to injection and production of fluids include final shut-in pressures from drill stem test, static bottom-hole pressure measurements from well completion histories, and idle well fluid level measurements for recent pressure data. Proprietary experimental pressure, volume and temperature data (PVT), gas oil ratios (GOR), well by well permeability, porosity, and oil gravity, and relative permeability and perforation intervals are used to create static and dynamic multiphase fluid flow models. All data collected was logged and entered into excel spreadsheets and mapping software to create subsurface structure, reservoir thickness and pressure maps, cross sections, production/injection charts on a well-by-well basis, and both static and dynamic flow models. This data is used to determine storage capacity and the amount of pressure variance within the field to determine how the reservoir will react to CO₂ injection and to gain insight into the subsurface fluid movement of CO2. Results indicate a homogenous field with a storage capacity of approximately 26 Million Metric Tons of CO₂. Analysis of production by stream and pressure change through time indicates a strong water drive. The connection to a large and active aquifer allows pressure changes to be spread over large areas. Flow modeling will help to determine the impact that the water influx will have on storage capacity and EOR production potential.