辽河西部凹陷南段异常低压背景下的成岩动力学研究与成岩相预测  

Dynamics of diagenesis and prediction of diagenetic facies under abnormally low pressure in the Southern Liaohe West Sag

作　　者：孟元林[1] 吴琳[1] 孙洪斌 吴晨亮 胡安文[1] 张磊[1] 赵紫桐[1] 施立冬 许丞[1] 李晨[1] 

机构地区：[1]东北石油大学地球科学学院,黑龙江大庆163318 [2]中国石油辽河油田公司勘探分公司,辽宁盘锦124010 [3]C&C Reservoirs Inc. , Houston TX 77036, USA

出　　处：《地学前缘》2015年第1期206-214,共9页Earth Science Frontiers

基　　金：国家自然联合基金项目(U1262106)

摘　　要：辽河西部凹陷南段古近系砂岩中发育低压-异常低压,泥岩中发育超压。文中考虑低压对砂岩成岩作用的促进作用和超压对泥岩成岩作用的抑制作用,建立了适合于异常压力背景下的成岩作用数值模拟模型,模拟了该区的成岩演化史,预测了成岩阶段和成岩相。结果表明,在断陷期,辽河西部凹陷南段断裂活动强烈,大地热流高,成岩演化快;在裂后期,构造活动弱,大地热流低,成岩演化慢。目前,在深凹陷区沙河街组已进入中成岩阶段B期—晚成岩阶段,主要发育致密储层;在斜坡带沙河街组主要处于早成岩阶段—中成岩阶段A期,发育常规储层。Low-abnormally low pressure in the sandstones and overpressure in the mudstones were developed in the Paleocene of the Southern Liaohe West Sag.The diagenesis were accelerated by the low pressure in the sandstones and retarded by the overpressure in the mudstones.A new numerical model was built,which could be used to simulate the diagenetic history and predict diagenetic stages and facies under abnormal pressure systems.The results show that the syn-rift stage is characterized by intensive fault activities,high heat flow and high diagenesis rate,contrasting to the weak tectonic activity,low heat flow and low diagenesis rate of post-rift stage.The part of Shahejie Formation at the deep sag has entered the phase B of middle diagenetic stage to late diagenetic stage,forming tight reservoirs,while part of Shahejie Formation at the slope area is mainly at early diagenetic stage to phase A of middle diagenetic stage,forming conventional reservoirs.

关 键 词：致密砂岩 非常规油气 异常低压 超压 成岩史 辽河西部凹陷 

分 类 号：P618.13[天文地球—矿床学]