【摘要】 本文论述了钻孔崩落椭圆与地应力之间的关系,指出崩落椭圆的形成,是由于孔壁附近应力集中而引起的崩落现象,其长轴方向与最小水平主应力方向相平行。 根据在唐山地区2000—4000米深度范围内的三口石油钻孔中的测量结果,得出钻孔崩落椭圆的平均长轴方向为 N 7°W,由此确定的区域地壳最大水平主应力方向为 N 83°E。 最后,我们把钻孔崩落椭圆的结果同该区的震源机制、地应力解除和水力压裂的结果进行了比较,表明均具有良好的一致性。更多还原

【Abstract】 This paper deals with the relationship between borehole breakouts and crust stress. It is suggested that the formation of borehole breakouts is the result from the stress concentration close to the borehole wall. The direction of the long axis of breakouts is paralled to the direction of minimum horizontal principal stress.On the bases of measurement results in the depth of 2000-4000 metres in 3 oil boreholes in Tangshan area, the average direction of long axis of breakouts obtained in this area is N7 °W. Therefore, the regional direction of maximum horizontal principal stress determined is N83° E.Finally, by comparing the result from the borehole breakouts measurement with that of focal mechanism, overcoring relif and hydraulic fracturing in the same area, It is found that their principal stress orientations are consistent.更多还原