DEVELOPMENT CHARACTERISTICS OF FAULTS AND THEIR CONTROL TO HYDROCARBON ACCUMULATION IN THE SONGZHAN-SHANGJIA AREA,NORTHERN SONG-LIAO BASIN

The geological data and earthquake interpretation in the studied area shows faults are banded on plane from the depth to surface. The direction is unanimous, dominant in near-SN (Shangjia work area) and NW (Songzhan work area), the near-EW-trending faults are the least. Most faults occur in the T2 (the top of the Quantou Formation ) and few faults in the T3(the top of the Denglouku Formation). The result displays that forming periods of faults had four types: earlier, middle, later and long-term, the middle and later faults are predominant. Synthetic analysis shows faults in the work area controlled the formation of hydrocarbon reservoir and fault blocks, forming a series of structural and structural-lithological reservoirs. These faults can become migration pathways during the mobilized period. On the other hand, faults play a role to laterally close the reservoirs and conserve hydrocarbon. By comparing and analysing seismic cross-sections, we suggest the lateral seal of reverse normal faults is good to conserve oil and gas of the studied area, hence obviously controls hydrocarbon formation.