渤中8-4油田"S"型走滑转换带特征及其对浅层油气侧封的控制作用OACSTPCD

The neotectonic movement in Bohai Sea of is very intensive,forming a unique strike-slip structural system and shallow reservoir formation in the Bozhong Sag.Previous studies focused mostly on the demonstra-tion of strike-slip movement and the discussion on the types of strike-slip transform zone,and there is a lack of de-tailed research on the role of reservoir controlling by the strike-slip transform zone.We studied the characteristics of S-type strike-slip transform zone in Bozhong 8-4 Oilfield and its control on the lateral sealing of oil and gas us-ing seismic data and oilfield cases.Results show that the main fault in the Bozhong 8-4 Oilfield is an S-type strike-slip transform system,in which pressure-releasing belt and pressure-boosting belt are developed.In the pressure releasing belt,the strata are steep and traps are poorly developed,which is the filling zone of oil and gas from deep to shallow.The pressure-boosting belt is characterized by gently-dipping strata,clear anticline shape,and dense low-amplitude nose-like faults and faulted-block traps,forming oil and gas accumulation rooms.Meanwhile,we proposed the strike-slip fault sealing index with which the lateral sealing ability of the strike-slip transform belt could be quantitatively characterized.According to the statistics of nearly 20 oilfields,the value of the strike-slip fault sealing index at 4 can be regarded as the critical point of the lateral sealing of the strike-slip fault.The re-search results provide a new method and idea for exploration in shallow oil and gas under sand-rich background.