3-D SEISMIC INTERPRETATION OF THE FRUITLAND FORMATION AT THE SOUTHWEST REGIONAL PARTNERSHIP CO2 SEQUESTRATION SITE SAN JUAN BASIN, NEW MEXICO

This paper reports on the use of 3D seismic analysis, to evaluate reservoir compartmentalization and the presence of possible faults and fracture zones within the Fruitland Formation at the Southwest Regional Partnership (SWP) on Carbon Sequestration’s San Juan Basin pilot site. The site is located in the Fruitland coal High Rate Fairway. Reservoir compartmentalization caused by fracture zones and faults will influence CO₂ flow from the injection well into the reservoir. Geobody interpretation and post-stack processing of 3D seismic data are used to explore the Fruitland seismic sequence for evidence of compartmentalization, fracturing and faulting. Box probes used to examine internal acoustic properties of the Fruitland sequence reveal considerable heterogeneity suggesting varying levels of pod-like coal distribution within the Fruitland. Heterogeneity is most prevalent in the upper coal which is interpreted to consist of several closely spaced pods. The lower Fruitland coal is more continuous but is characterized by considerable variability in acoustic response. Variance, Ant-Tracking and gradient magnitude attributes were used to explore the sequence for evidence of fracturing and faulting. Interpretation suggests the presence of small faults or fracture zones within the reservoir that have dominant northeast-southwest trend. Internal heterogeneity within the Fruitland sequence may control the distribution of injected CO₂ and limit storage capacity. A 3D model of the Fruitland reservoirs will be developed to serve as a basis for flow simulation in collaboration with NETL and the WVU/ORD model development efforts. The project is funded by the U.S. Department of Energy and is managed by the National Energy Technology Laboratory and the Southwest Regional Partnership.