断块油气藏型储气库封闭性评价研究——以大港油田板中北储气库为例

Study on UGS Sealing Evaluation of Fault-block Oil & Gas Reservoir——A Case Study of the Banzhongbei UGS in Dagang Oilfield

以大港油田板中北储气库为例,利用多种资料,从盖层、断层和水体三方面论述断块型储气库运行前后的封闭性。首先利用静态、动态资料,对储气库建库前的封闭性进行评价,然后利用现场监测资料,对储气库运行后的封闭性进行论述。钻井显示板中北储气库为板1油组和板0油组泥岩形成的双盖层,全区分布;泥岩排替压力大于储气库剩余压力,封闭性好;定性评价断层两盘岩性配置,定量分析泥岩涂抹、压力、气体组分等断层封闭性判断要素,结果表明板桥断层建库前后封闭性好,板816断层建库前封闭,注采气后断层活化;原始油水界面距圈闭溢出点15~65 m,边水密封性好,经过周期性注采后,注采压降、注采比变化平稳,水体推进均匀,水体封闭性较好。

Taking the Banzhongbei underground gas storage in Dagang Oilfield as an example,this paper discusses the cap rock sealing capacity,fault sealing capacity and water sealing capacity before and after operation of Banzhongbei underground gas storage.Firstly,the static and dynamic data are used to evaluate the sealing of the Banzhongbei reservoir before the operation of Banzhongbei underground gas storage,and then the monitoring data are used to discuss the closure of the underground gas storage after the operation of Banzhongbei underground gas storage.The double cap rock of the Ban 1 and Ban 0 mudstone formation is distributed in the Banzhongbei underground gas storagae according of drilling,and the mudstone displacement pressure is greater than the gas storage residual,so the cap rock sealing capacity is effective.The Qualitative and quantitative evaluation show that the sealing of the Banqiao fault is effective,and the Ban 816 fault is sealed before the operation of Banzhongbei underground gas storage and the fault is activated after the gas injection.The distance between the original oil-water interface and the trap overflow point is 15-65m.The injection-production ratio and the promoting speed of water body are changed smoothly after cyclical injection,so side water sealing is effective.