Using MT data to find velocity traps in middle and shallow layers

Abstract

In the complex piedmont oil and gas exploration, due to the large change of lithology in the middle and shallow strata, the vertical and horizontal changes of velocity in the middle and shallow strata are more intense. It is difficult to identify some strata with obvious changes in velocity on the seismic section, which leads to the inaccuracy of velocity model or obvious velocity trap in the seismic prestack depth migration processing. This will further cause the incorrect deep structure and target layer solution. MT method are mainly characterized by deep sounding depth, high sensitivity to high conductivity geological bodies in high resistivity layers. This makes it very effective to study the deep structures of basements and lithology distribution. We here analyze the technical advantages of MT method in tracing in middle and shallow layers by MT modeling geoelectric model of mountainous areas, and demonstrate that MT method can play an important role in oil and gas exploration in complex areas, especially in finding velocity traps for seismic processing by analyzing some cases.