牛35块沙河街组三段Es_3~中现今地应力研究

牛庄油田牛35块位于牛庄洼陷西北坡,现今地应力对油田的开发有着重要的影响.综合采用了声速法、井壁崩落法、井斜统计法、声发射法和水力压裂法对关键井点的水平主应力方向和大小进行计算,在此基础上运用有限单元法对牛35断块沙河街组三段Es3中现今地应力进行了数值模拟.研究结果表明:牛35块最大水平主应力方向近东西,在断块内部最大水平主应力65MPa左右,最小水平主应力60MPa左右,分布较稳定.

Study on the present ground stress of Es3中 in Niu 35 fault block

Niu 35 fault block of Niuzhuang oilfield is located in the northwest slope of Niuzhuang Sag.The present ground stress of it has important effect on the exploitation of the oilfield.The horizontal principal ground stresses of some key wells are calculated by comprehensively using acoustic velocity method,borehole breakouts method,well deviation statistics method,acoustic emission method and hydraulic cracking method.On the basis of this,the present ground stress of this fault block is numerically simulated.The result of the numerical simulation shows that,the direction of the maximal horizontal principal stress of this fault block is close to west-east and its value is 65 MPa;the value of its minimal horizontal principal stress is about 60 MPa;therefore the distribution of its present ground stress is comparatively stable.