Improvements in Hydrofracturing Procedure and InterpretationThrough Laboratory Tests

在过去的15年中，水力压裂法的地应力测量已经发展成为地球物理研究中不可或缺的工具。例如，在美国加利福尼亚州的Cajon Pass进行的第一次深层科学钻探的主要目的是通过水力压裂法测量圣安德烈亚斯断层附近的应力状态。尽管水力压裂的总体可靠性较高，但其解释仍然存在不确定性，并且该方法仅部分成功或完全不成功的案例正在浮出水面。水力压裂数据解释的困难至少有三个主要来源：(1)从现场记录中读取正确的压力，(2)使用正确的模型计算原位应力，(3)评估先前存在的裂缝对水力压裂压力和方向的影响。这项研究试图通过实验室测试和数据分析来解决其中的一些困难。此外，还将对提出的方法的创新改进进行实验验证。这种对一种或多种替代技术的确认，将使它们能够补充或取代传统的水力压裂。

The hydrofracturing method of in situ stress measurement has evolved in the last fifteen eyars into an indispensable tool in geophysical research. For example, a major objective of the first deep scientific drilling in the U.S. at Cajon Pass, California, is to measure the state of stress, primarily by hydrofracturing, in the vicinity of the San Andreas fault. Depsite the general reliability of hydrofracturing, uncertainties in its interpretation still exist and cases where the method is only partially successful or totally unsuccessful are now surfacing. There are at least three major sources of diffi- culties in hydrofracturing data interpretaion: (1) reading the correct pessures from field records, (2) using the correct model for calculating the in situ stresses and (3) evaluating the effect of preexisting fractures on hydrofrac pressures and directions. The research is an attempt to resolve some of these difficulties through laboratory testing and data analysis. In addition, experimental verification of suggested innovative improvements of the method will be carried out. Such confir- mation of one or more of these alternate techniques would enable their use in either complementing orreplacing conventional hydrofracturing.