单一倾斜裂缝的双侧向测井响应

THE DUALLATEROLOG RESPONSE OF THE SINGLE DIPPING FRACTURE

利用三维有限单元法计算了过井单一倾斜裂缝的双侧向测井响应；结果表明，随着裂缝倾角的增大，响应曲线将变得平缓。对无限侵入（裂缝中充满泥浆）的情形，在裂缝中点处，当倾角小于临界角时，深浅侧向电阻率之间表现出负差异；当倾角大于临界角时，深浅侧向电阻率之间表现出正差异。在不同倾角下，深浅侧向电导率随裂缝张开度的增大而增大；当倾角不变时，深浅电导率之差与裂缝张开度几乎成正比关系。

The 3-D finite element method(FEM)was used to compute the dual laterologresponse of single dipping fracture crossing the borehole. The result shows that the responsivecurve becomes blunter with the increasing of fracture dipangle. As for the infinite invasioncase(the fracture is full filled with thc mud)and when the center of the dual laterolog tool islocated at the midpoint of the fracture,the difference between the deep and shallow laterologresistivities is negati ve when the dipangle is less than critical angle, and the difference ispositi ve when the di pan8le is greater than critical angle,In this paper.the relationshipbetween the di fference obtained from the dual laterolog conductivities,and the fractureopening is also given.