岩石的外观体积和流固两相压缩系数

Compressibility coefficients of bulk volume and fluid-solid of rocks

岩石有3个体积和3个应力,因此岩石有多个压缩系数。油藏工程主要研究了孔隙压缩系数的计算和应用问题,对其他的压缩系数研究甚少。对外观体积和流固两相的压缩系数进行了研究,并分别推导出了它们的计算公式。岩石外观体积对孔隙压力的压缩系数与孔隙压缩系数相同。岩石外观体积对外压的压缩系数是孔隙度和骨架压缩系数的函数。岩石流固两相压缩系数为流体压缩系数和骨架压缩系数的加权调和平均值或加权倒数算术平均值,孔隙度为权值。

Rocks have three volumes and three stresses, so have several compressibility coefficients. Pore compressibility and its applications have been mainly studied in reservoir engineering, and others are seldom touched. This paper focused on the compressibilities of bulk volume and fluid-solid of rocks, and derived their calculation formula. The compressibility of bulk volume of rocks to pore pressure is the same of pore compressibility of rocks. The compressibility of bulk volume of rocks to outer pressure is the function of porosity and skeleton compressibility of rocks. The two-phase compressibility of fluid-solid of rocks is porosity-weighted harmonic mean of fluid compressibility and skeleton compressibility, or porosityweighted arithmetic mean of reciprocals of fluid compressibility and skeleton compressibility.