Connecting seismic attributes with production performance at Camarupim Gas Field, Espirito Santo Basin, Brazil

Abstract

We describe an integrated approach that connects production performance with elastic and geometric seismic attributes to define the role of rock matrix and fractures/faults on gas production from Camarupim Field, offshore Brazil. Discovering, appraisal and development comprise three vertical and four horizontal wells, grossly 1000 meters long, showing very distinctly absolute open flows (AOFs) during tests. Multi-scaled data, seismic, logs and lab-based supported elastic inversion feasibility analysis to understand and correlate band limited Poisson-Ratio (PR) and P-Impedance (Ip) cubes with rock properties. Positive PR and negative Ip values are associated with shales, while sands relate to negative PR and a wide range of positive and negative Ip values, the later ones assigning best sand quality. Better facies detection was guided by combining PR and Ip cubes in a particular way, taking only negative values and zeroing the positive values of PR. Positive values in this product cube relates to better facies (Ip<0 and PR<0). Product and discontinuity volumes were then integrated to connect changes in facies and/or fault/fracture or both with changes in production performance. Although facies related attributes allow reservoir quality discrimination, the well path direction across fractures/fault architecture plays the main role in field productivity.