The exploration accuracy of reflective seismic is insufficient due to the undulating structure of the coal seam which causes the difficulties to penetrate the coal seam through horizontal drilling. It’s very urgent to identify the trend of underground coal seams and the regional tectonic morphology accurately.
The seismic frequency resonance technique was used to image the coal seam at a depth of 1100-1250 meters, and the coal seam distribution and geological structure of the area were finely identified.
The blue color means Low rock wave impedance value which reflects weak coal formations;
The disconnection of the blue clumps reflects the position of the fracture structure
Five faults can be seen in the imaging profile, and the trend of the coal seam is controlled by the fracture structures, which causes the difficulties to penetrate the coal seam through horizontal drilling.
The re-layout drilling was carried out according to this new result, and the faults we speculated were verified one by one through drilling! We guided the drilling of horizontal wells successfully with a deviation of 0.3% on depth finally.