【摘要】 本文根据钻孔崩落椭圆是由水平地应力引起孔壁在最小水平主应力方向发生剪切破坏的理论,讨论了由崩落椭圆确定水平主应力方向问题。讨论了地层倾角和四臂井径测井的测量方法、资料处理以及识别崩落椭圆的原则,并列举出两个不同类型的实测例子。最后分析了河南濮阳地区的29个钻孔的地层倾角和四臂井径测井资料,得出该地区的平均崩落椭圆长轴方位是 N15°E,由此确定的最大水平主应力方位是 N105°E。更多还原

【Abstract】 Based on the theory that borehole breakouts are caused by the shear failure of the borehole wall in the direction of minimum horizontal principal stress, this paper discusses the problem of determining the direction of the horizontal principal stress from borehole elongation.The measuring method of four-arm diameter log, data processing and the principle of identification of breakout are discussed, and then two different kinds of examples are given.Finally, the records obtained from four-arm diameter log of 29 oil-well in the Pu Yang area, Henan province are analysed. It turns out that the mean orientation of breakouts in this area is N 15°E and the orientation of maximum horizontal principal stress determined is N 105°E.更多还原