Walkaway Vertical Seismic Profiling (WVSP) Modeling and Imaging Study along FaultedCoal Seams over a High Velocity Limestone Model: A Synthetic Study

The problem of collecting reflection data from the layers below a high velocity layer (HVL) and imaging those accurately is solved using walkaway vertical seismic profiling (WVSP) technique. procedure shown on dataset model highly faulted, thin-bedded coal separated by limestone. By locating receivers above, in, HVL, reflections are expected to be recorded locally in situ borehole HVL before they travel back surface as case seismic. results obtained (or synthetic) WVSP lead conclusion that promising may via acquisition field such well-imaged. Analysis test showed can imaged robustly when situated only, while strong images tend fade away lose their strength moved above HVL. However, both these cases receiver location geometry needed obtain vertically horizontally stable. When full instrumentation provided, good far 500 m VSP with various dips faults nearly 800 depth surface. Two velocities (4000 m/s 5000 m/s) tested for limestone layer. Both Unfortunately, some pulled-up effects seen right where immediately correct locations, corrected deeper sections however. Comparison converted corridor stack zero offset migrated image show agreement.