鄂尔多斯盆地马岭油田长7致密储层古今构造应力研究

摘要

Tectonic stress is one of the controlling factors of hydrocarbon migration and accumulation.The study of stress state on paleo-tectonic and present tectonic is of great significance to the exploration and development of oil and gas.Temperature measurement of fluid inclusion,paleomagnetic fracture orientation,acoustic emission method,microseismic monitoring,rock compression experiment and hydraulic fracturing method are applied respectively to the study of paleo-tectonic and present tectonic stress in the Chang 7 tight reservoir of Maling oilfield in Ordos Basin.The results show that the crucial period of fracture formation in the Chang 7 tight reservoir is the Ⅳ stage of the Yanshan movement,with the horizontal maximum principal stress direction of 84° and effective stress 44 MPa,while the current horizontal maximum principal stress direction is 76° and the current effective stress of minimum principal stress is 15 MPa.%构造应力是油气运移与富集的控制因素之一,古今构造应力状态的研究对油气勘探与开发具有重要意义.利用流体包裹体测温、古地磁裂缝定向、声发射法和微地震监测、岩石压缩试验和水力压裂法分别对鄂尔多斯盆地马岭油田长7致密储层古今构造应力进行研究.结果表明:长7致密储层裂缝发育关键期为燕山运动Ⅳ幕,其水平最大主应力方向为84°,有效应力大小为44 MPa;现今水平最大主应力方向为76°,而现今水平最小主应力有效应力大小为15 MPa.