The Advantages of Pre-stack Inversion in Heterogeneous Carbonate Reservoir Prediction - A Case Study from Tarim Basin, China

We present a numerical evaluation of the seismic response due to fluids in the pore space of coalbeds for the Corbett Field, located 145Km to NW of Edmonton, Alberta, Canada to simulate the replacement of brine by methane in coalbeds. We use Palmer and Mansoori analytical model and Gassmann equation to generate synthetic seismograms to evaluate seismic as a monitoring tool for methane production. In the Corbett Field the targets are two coal seams of the Mannville Group, the Main Seam and the Lower Seam. Based on sonic and density log from the well 100-03-22-062-06W500 of the Corbett Field, we perform a fluid simulation to make an assessment of its production forecast in an 8 years period and a fluid substitution to estimate the variation of the seismic properties during production. We use the Gassmann equation to substitute 100% brine (initial state) in the pore space of Main Seam and Lower Seam by a combination of brine (82%) and methane (18%) and then we generate the synthetic seismograms. As the result, synthetic seismograms show, the Main and Lower Seam as a single unit and the substitution of brine by methane did not generate a significative response.