利津洼陷沙四上亚段超压成因及压力预测

Causes of Overpressure and Pressure Prediction in the Upper Member of Shahejie Formation in Lijin Depression

利用地震、测井、地质及相关的分析化验等资料,研究了利津洼陷超压分布及演化特征。分析了利津洼陷超压成因,明确了欠压实、构造挤压和生烃增压作用是主要超压成因机制。针对不同超压成因选取较合适的技术方法,利用泥岩声波时差定量计算欠压实作用(包括构造挤压作用)形成的超压,通过生烃作用形成的增压校正,对利津洼陷及其周边的地层压力进行了精细预测,获得了更为准确的现今压力场。研究异常高压对油气运移和成藏的控制作用,并基于地层压力预测结果,指导超压区岩性油藏的井位部署,取得了较好应用效果。

Based on seismic,logging,geological and related analytical tests,this paper discussed the overpressure distribution and evolution characteristics of Lijin Depression. The causes of overpressure in Lijin Depression were analyzed in under-compaction,tectonic extrusion and hydrocarbon generation. The supercharging effect is the main overpressure mechanism;the appropriate technical method is selected for different overpressure genesis,and the overpressure generated by the under compaction (including structural extrusion) is quantitatively calculated by the mudstone acoustic time difference. It is formed by hydrocarbon generation. The supercharge improvement corrects the formation pressure in Lijin depression and its surrounding areas. It obtains a more accurate current pressure field in the control effect of abnormal high pressure on hydrocarbon migration and accumulation. Based on the prediction results of formation pressure,we have achieved good application results.