岩石弹性参数对渗流测试分析的影响

岩石的动、静弹性参数在地质勘探与油气开发等多种工程技术领域均有着重要的应用意义。采用岩石物性参数自动测试系统，进行了实验测试分析，得到了不同岩石的动、静弹性模量和动、静泊松比。分析结果表明：不同岩性的岩石动、静弹性参数关系并非线性关系，其中储层砂岩的动、静弹性模量关系为幂函数曲线，砂岩的动、静泊松比关系为二次函数曲线；使用上述函数，可以由岩石动弹性模量与动泊松比计算出储层岩石静弹性模量及静泊松比，再根据弹性模量与压缩系数的关系，可准确获得储层岩石的压缩系数，从而为油气渗流测试分析提供精确的基础资料。此外，根据砂岩气藏渗流气井实测压力恢复资料，进行了实例井的试井分析，得到了砂岩气藏渗流气井压力历史拟合曲线和双对数拟合曲线。研究表明：当岩石体积模量减小（即岩石压缩系数增大）引起综合压缩系数增大20%时，得到的岩石渗透率减小24.73%，井筒存储系数增大3.7%，表皮系数减小44.92%。因此，岩石弹性参数对渗流测试分析有着较大地影响。

INFLUENCE OF ROCK ELASTIC PARAMETERS ON TEST ANALYSES OF FLOW IN ROCK

Dynamic and static elastic parameters of rock have much significance in geology, exploration, development engineering of oil-gas and other engineering. Through experiments being performed by using a system of rock physical parameters testing, dynamic and static elastic modulus and Poisson's ratio of rock have been obtained. Results show that relationships between dynamic elastic modulus and static elastic modulus or dynamic Poisson's ratio and static Poisson's ratio of rock are not linear; that the relationship between dynamic elastic modulus and static elastic modulus of sandstone are power function curves; and that the relationship between dynamic Poisson's ratio and static Poisson's ratio of sandstone are quadratic function curves. Static elastic modulus and static Poisson's ratio of rock can be calculated from dynamic elastic modulus and dynamic Poisson's ratio of rock according to the above functions. An exact compressibility of rock can be calculated from elastic modulus. It provides exact data for test analysis of oil and gas flow in reservoirs. Furthermore, a gas well test analysis was taken as an example from data of restored bottom-hole pressure of a gas well in a sandstone gas reservoir. A historical matching curve of pressure and double-logarithmic curves were got for the gas well. Results show that permeability of rock decreases by 24.73%, that well-bore storage factor increases by 3.7%, and that skin factor decreases by 44.92% when a total compressibility decreases by 20% with elastic modulus of rock decreasing or compressibility of rock increasing. It is concluded that elastic parameters of rock has much influence on percolation test analysis.