APPLICATION OF POST-STACK HYDROCARBON DETECTION TECHNOLOGY BASED ON MATCHING PURSUIT ALGORITHM TO QHD33/34 STRUCTURE, BOHAI BAY BASIN

The structure of QHD33/34 is located on the middle and southeastern middle slope of the Shijiutuo Uplift. Affected by neo-tectonic movement, there are a series of NE and EW active faults in the shallow part of the Shijiutuo Uplift, and a number of fault-nose and fault-block traps have been found in the Minghuazhen Formation at the shallow zone of the slope belt. However, the structural traps are generally small in scale and low in amplitude. Migration and accumulation of oil and gas are easy to be affected by the faults. In order to reveal the oil-gas-bearing possibility of shallow reservoir in the structure QHD33/34, the method of low-frequency gradient anomaly based on the matching pursuit algorithm is used to detect the hydrocarbons in this area. The agreement rate between the final result of hydrocarbon detection and oil-gas-bearing possibility of shallow reservoir may be as high as 79%. The results suggest that the method is effective to the identification of both the oil reservoir and water layer to the greatest extent and useful for well location placement in the shallow part of the structure, and helpful to avoid risks as much as possible. Using this method we may identify the oil reservoir thicker than 3 meters, but response to water layer is not clear.