济阳坳陷致密砂岩储层油气成藏机理探讨

Hydrocarbon accumulation mechanism of tight sandstone reservoir in Jiyang Depression

刘传虎 王永诗 韩宏伟 王学忠

Liu Chuanhu Wang Yongshi Han Hongwei Wang Xuezhong

中国石化 胜利油田分公司, 山东 东营 257001

SINOPEC Shengli Oilfield Company, Dongying, Shandong 257001, China

致密砂岩储层渗透率小于10×10-3μm2,由于其储集空间类型及特征的特殊性,在油气成藏机理方面与常规油气藏存在根本的区别。该文从分析"根缘气"的形成条件及成藏特点出发,以模拟实验为基础,根据济阳坳陷致密储层特点,探讨油气成藏机理:致密储层油气运移成藏以超压充注为主,超压传递到达的边界就是其含油(气)边界,超压梯度大,油气充注的距离和圈闭滞留的范围就大,含烃饱和度也相对高。通过成藏相似性研究认为,济阳坳陷致密砂岩油气藏具以下特点:①烃源岩持续供烃,源内及附近储层蕴含着大量的分异性较差的油气;②致密砂岩储层"相势控藏";③具有大面积分布致密油气藏的条件,勘探潜力大。

The permeability of tight sandstone reservoirs is below 10×10-3 μm2. Due to the particularity of reservoir space type and characteristics, the tight sandstone reservoirs are different from normal ones in hydrocarbon accumulation mechanism. The generation conditions and accumulation features of "source-contacting gas" are studied. Based on simulation experiments, hydrocarbon accumulation mechanism is concluded according to the features of tight sandstone reservoirs in the Jiyang Depression. Overpressure charging is the main way of hydrocarbon migration and accumulation in tight sandstone reservoir. The border for overpressure transfer is the boundary for oil or gas. When overpressure gradient is larger, the distance of hydrocarbon charging and the range of trap will be larger, and the hydrocarbon saturation will be higher. Through similarity research, the tight sandstone reservoirs in the Jiyang Depression have the following characteristics. 1) Source rocks contribute to hydrocarbon continuously. Large quantity of oil and gas with poor diversity exist in source rocks or neighboring reservoirs. 2) In tight sandstone reservoirs, facies and potential control accumulation. 3) Tight reservoirs may exist widely, indicating for good exploration potential.

中国石油化工股份有限公司重大基础研究项目"盆地升降过程油气富集机理及富集模式"(P06086)资助

https://doi.org/10.11781/sysydz201302115