Organization
Bohai Oilfield Research Institute, Tianjin Branch of CNOOC Ltd., Tianjin 300459, China
摘要
在地震资料精细解释基础上，采用去压实和古水深校正方法对渤海X油田沙二段沉积后古地貌进行了恢复，划分出沟谷、凹陷、斜坡和凸起等4种地貌单元，并对地貌单元控制下的储层质量进行了分析。结果表明：沟谷、凹陷单元砂体厚度大，泥质成分少，压实、胶结作用弱，溶蚀作用强，储层物性好。凸起单元砂体厚度小，泥质成分多，压实、胶结作用强，溶蚀作用弱，储层物性差。斜坡单元砂体厚度较大，迎主河道方向，水动力较强，泥质成分较少，储层物性较好；而背对主河道方向，受凸起遮挡，水动力较弱，泥质成分较多，储层物性较差。生产动态数据表明，沟谷、凹陷单元钻井产能高，凸起单元钻井产能低，斜坡单元迎主河道方向钻井产能较高，背对主河道方向钻井产能较低。此外，综合考虑砂岩厚度、古水深和比采指数等因素，预测有利储层分布区域3个。
Abstract
Based on the detailed seismic profile interpretation, decompaction and paleo?鄄depth correction method were used to restore the geomorphology conditions after the deposition of Sha?鄄2 Formation in X oilfield of Bohai Bay. Four geomorphic units, including paleo?鄄valley, paleo?鄄sag, paleo?鄄slope and paleo?鄄uplift, were defined and the reservoir quality of all geomorphic units was analyzed and discussed. The results show that, among all geomorphic units, the sandstone reservoirs developed in paleo?鄄valley and paleo?鄄sag units have the characteristics of thick formations, low clay content, weak compaction and cementation, strong dissolution and good reservoir properties; while the sandstone deposited at paleo?鄄uplift has the characteristics of thin formation, high clay content, strong compaction and cementation, weak dissolution and poor reservoir quality; the sandstone deposited on paleo?鄄slope has the characteristics of thick formation, less clay content due to strong hydrodynamic condition in the main drainage direction and good reservoir property; in contrast, in the opposite direction of main drainage line, due to the isolation of paleo?鄄uplift, sandstone generally has high clay content due to weak hydrodynamics, and its reservoir property is relatively worse along this direction. Meanwhile production performance data show that well productivity is high in paleo?鄄sag units and low in paleo?鄄uplift; at the paleo?鄄slope area, well productivity is high along the main drainage direction and low in the opposite direction. In addition, comprehensively considering the factors such as sand thickness, paleo?鄄water depth and specific productivity index etc., three beneficial zones are predicted.
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