石油与天然气地质 ›› 1998, Vol. 19 ›› Issue (2): 116-123.doi: 10.11743/ogg19980206

• 论文 • 上一篇    下一篇

压实盆地自然水力破裂及其动力学

张小莉, 冯乔, 李文厚   

  1. 西北大学地质学系, 陕西西安710069
  • 收稿日期:1997-11-25 出版日期:1998-06-25 发布日期:2012-01-18

NATURAL HYDRAULIC FRACTURE IN COMPACTED BASIN AND ITS KINETICS

Zhang Xiaoli, Feng Qiao, Li Wenhou   

  1. Department of Geology, Northwest University, Xi’an, Shaanxi
  • Received:1997-11-25 Online:1998-06-25 Published:2012-01-18

PDF (PC)

672

被引次数

19

摘要：

压实盆地中的自然水力破裂是欠压实带孔隙流体排驱的关键因素之一。欠压实带可描述成被“壳”包围的一个异常孔隙流体压力带。当盆地在连续沉积(加载)和不断剥蚀(卸载)作用过程中,其“壳”的自然水力破裂动力作用是完全不同的。在加载条件下,欠压实带的顶、底壳发生剪切破裂,底壳早于顶壳。在卸载条件下,只有当剥蚀所引起的负荷压力降大于“壳”发生垂直张破裂所需要的最小负荷压力降时,壳才会破裂,且主要为顶壳破裂。对于经历了多期沉积-剥蚀作用过程的地区或盆地,其欠压实带中孔隙流体的排驱可以被描述成首先向下,然后向上,再向下再向上这样一个排驱方向不断变化的间歇性过程。

关键词: 压实作用, “壳”, 自然水力破裂, 流体排驱, 动力学

Abstract:

In a compacted basin,natural hydraulic fracturing is one of the key factors of the pore fluid expulsion of uncompacted belt.An uncompacted belt can be described as an abnormal pore fluid pressure belt surrounded by “shell”.The kinetics of the natural fracturing of the “shell” in continous sedimentation(loading)is different from that in succesive erosion(unloading).In loading condition,the shear fracturing of the bottom shell of the uncompacted belt would appear earlier than that of the top.In unloading condition,the “shell” would crack only when the load pressure decrease resulted from erosion is greater than the minimal load pressure required in vertical tensile crack of the “shell”,and the crack usually happens on the top shell.In this view,the expulsion of the pore fluid of the uncompacted belt can be described as a intermittent change process of expelling up and down.