The Buena Vista Hills Field is located about 25 miles southwest of Bakersfield, in the San Joaquin Valley (SJV), California. The Antelope Shale zone was discovered at the Buena Vista Hills in 1952, and has since been under primary production. Little research was done to improve the completion techniques during the development phase in the 1950s, so most of the wells are completed with about 1000 feet of slotted liner. The primary objective of this research is to conduct advanced reservoir characterization and modeling studies in the Antelope Shale reservoir. Characterization studies will be used to determine the technical feasibility of implementing a C02 enhanced oil recovery project in the Antelope Shale in Buena Vista Hills Field. The proposed pilot consists of four existing producers on 20 acre spacing with a new 10 acre infill well (6532) drilled as the pilot CO, injector. Most of the reservoir characterization during Phase I of the project will be performed using data collected in the pilot pattern wells. This is the second annual report of the project. It covers the period February 7, 1997 to February 6, 1998. During this period the following tasks have been completed: laboratory wettability; specific permeability; mercury porosimetry; acoustic anisotropy; rock mechanics analysis; core description; fracture analysis; digital image analysis; mineralogical analysis; hydraulic flow unit analysis; petrographic and confocal thin section analysis; oil geochemical fingerprinting; production logging; carbon/oxygen logging; complex lithologic log analysis; NMR T2 processing; dipole shear wave anisotropy logging; shear wave vertical seismic profile processing; structural mapping, and regional tectonic synthesis. Crosswell seismic was run in the pilot wells and attenuation imaging is proceeding. Both the 3D earth model and C02 coreflooding are close to completion. Lastly a potential target interval has been identified and plans are underway to hydraulically fracture and complete the 6532 well. Noteworthy technological successes for this reporting period include: 1) First (ever) high resolution, crosswell reflection images of SJV sediments; 2) first successful application of the TomoSeis acquisition system in siliceous shales; 3) first detailed reservoir characterization of SJV siliceous shales; 4) first mineral based saturation algorithm for SJV siliceous shales, and 5) first C02 coreflood experiments for siliceous shale. Preliminary results from the C02 coreflood experiments (2500 psi) suggest that significant oil is being produced from the siliceous shale. This stage of the experiment is in its 5th week, and oil recovery continues.