前梨园地区深层致密气超压特征及成藏效应  

Overpressure feature and its implications on hydrocarbon accumulation of tight gas reservoirs in Qianliyuan depression

作　　者：梁正中[1,2,3] 王镜惠[1] 袁波[2] 常振恒[3] 

机构地区：[1]榆林学院能源工程学院,榆林719000 [2]中国石化中原油田分公司勘探开发研究院,濮阳457001 [3]中国科学院地质与地球物理研究所,北京100029

出　　处：《地球物理学进展》2017年第2期684-688,共5页Progress in Geophysics

基　　金：榆林学院高层次人才科研启动基金(2016GK18);国家油气重大专项(2011ZX05006)

摘　　要：以致密气藏为代表的非常规油气藏勘探在国内逐渐得到重视.前梨园洼陷是东濮凹陷最大的生油气洼陷,展示了极好的深层超压天然气勘探前景.在实测压力基础上,结合声波时差及地震速度计算,利用东濮凹陷丰富的测井、测试和地质资料综合分析超压分布和成因.结果表明:前梨园地区地层压力在纵向上具有典型双层结构,其中沙三中下亚段超压普遍发育.泥岩层的压力分布与砂岩储层的压力分布特征具有一定差异,泥岩欠压实所产生的增压并不显著,生烃作用尤其是大量生气为区域超压形成的主要机制.超压的存在对天然气运聚成藏产生重要的影响.超压通过对成岩作用的影响,改善了深部砂岩储层物性从而提高储集性能.相同深度和储集条件下,油气层压力越高,相应含油气饱和度增高.加强超压相关研究对于本区深层致密砂岩气藏勘探意义重大.Abnormal fluid pressures are widespread throughout the global oil and gas basin and have great influence on generation, migration and preservation of hydrocarbon. The tight sand gas is one of the unconventional gas resources and it is also an important candidate resource of conventional gas in China. Qianliyuan sag is the biggest rich source kitchen in Dongpu Depression with good unconventional natural gas exploration prospect. According to the measured fluid pressure, mud stone sonic log and seismic velocity calculation, overpressure characteristics of deep formation in the area are described. Very high abnormal pressure mainly occurs in the middle and lower part of 3rd member of Shahejie Formation with the binary structure on the section that is normal pressure at the upper part and abnormal high pressure at the lower part.Overpressure evolution is summarized and a variety of processes have been proposed for the generation of overpressure. Because of hydrocarbon generation, overpressure intensity of deep Es3 is increasing from Nm up to now. Hydrocarbon generation is the most important mechanism for genesis of the overpressure system today and the compaction disequilibrium causes the overpressure to some extent in the area too. It also suggests that the distribution of abnormal pressure in mudstone and sandstone has certain difference.The formation of sand reservoir overpressure is due to transfer of hydrocarbon generation from mudstone.Overpressure plays a big role in migration and accumulation of tight sand reservoirs.It improves deep reservoir characteristic by changing processes of diagenesis. It is very benefit for hydrocarbon enrichment as the formation of overpressure is the result of the hydrocarbon charge. The higher the pressure, the better the oil/gas shows would be at the same burial depth and bearing condition. Hydrocarbon is also rich in overpressure or strong overpressure zone. Strengthening the study of overpressure is very significant for exploration and development of tight sand reservoir in th

关 键 词：超压 致密砂岩气 储层物性 含气性 成藏 

分 类 号：P631[天文地球—地质矿产勘探]