Mechanics of Hydraulic Fracturing
Mechanics of Hydraulic Fracturing
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DOI：
10.2118/686-g
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发表时间：
1972-12
期刊：
影响因子：
--
通讯作者：
M. K. Hubbert;David G. Willis
中科院分区：
文献类型：
--
作者：
M. K. Hubbert;David G. Willis
通过对井中施加压力对岩石进行压裂的理论研究，得出结论：无论压裂液是渗透型还是非穿透型，产生的裂缝都应该大致垂直于最小应力轴。地下应力的一般状态是三个主应力不相等的状态。对于以正断层为特征的构造松弛地区，最小应力应为水平方向，裂缝应为垂直方向，注水压力应小于上覆岩层的注水压力。在活动构造挤压地区，最小应力应为垂直方向，且应等于上覆岩层的压力；裂缝应为水平方向，注入压力应等于或大于上覆岩层的压力。小于覆岩总压力的水压不能产生水平裂缝。这些结论与现场压裂经验和室内实验结果相吻合。
A theoretical examination of the fracturing of rocks by means of pressure applied in boreholes leads to the conclusion that, regardless of whether the fracturing fluid is of the penetrating or nonpenetrating type, the fractures produced should be approximately perpendicular to the axis of least stress. The general state of stress underground is that in which the three principal stresses are unequal. For tectonically relaxed areas characterized by normal faulting, the least stress should be horizontal; the fractures produced should be vertical, and the injection pressure should be less than that of the overburden. In areas of active tectonic compression, the least stress should be vertical and equal to the pressure of the overburden; the fractures should be horizontal, and injection pressures should be equal to, or greater than, the pressure of the overburden. Horizontal fractures cannot be produced by hydraulic pressures less than the total pressure of the overburden. These conclusions are compatible with field experience in fracturing and with the results of laboratory experimentation.