油气层的速度问题

Velocity problem of oil and gas reservoirs

百灵计算技术应用研究所, 北京100083

Research Institute of Bailing Computing Technology Application, Beijing 1000083

油气层是双(三)相介质。从1928年起双相介质理论即已开始发展, 至今已有近二十种理论, 这些理论大致可分为三类, 即有效介质理论、自适应理论及接触理论, 文中大致作户介绍, 由于在中国东部油田应用中不很适应, 因而本文提出了一个圣百灵公式。经过多方测试, 圣百灵公式估算结果与实测结果误差较小。这个公式考虑到了骨架成份、泥质含量、孔隙率、流体成份、饱和度以及温度、压力、地下水含盐度等对油气层纵波速度的影响。可用来预测工区内油层或气层的速度, 从而掌握油气预测的依据；研究各种因素影响速度的程度；了解油气层的反射系数及岩性横向变化的影响, 从而了解亮点的变化规律。文中对这些问题分别进行了研究, 并与经典的Gassmann公式作了比较。

Oil and gas reservoirs are two-phase media. theory has been developed since 1928. To date ther are nearly twenty kinds of theories which can be roughly classified as three types,namely effecive media theory, adaptive theory, and conact theory. These theores are introduced in the paper. As the theories are not very suitable dries are not very suitable for the application in eastern China oilfield, a Shengbailing formula is proposed. Through tests in many ways, it produces very little error when comparing with actual results. The formula takes account of the influence of skeleton comopition, shale content, porosity, fluid composition, saturaion, temperature, pressure, and groundwater salinity on P-wave veloity of oil and gas reservoirs. The formula can be used to predict the velocities of oil or gas reservoirs in working area, study the degree of various factors affecting velocities, and comprehend the lateral variations of the reflection coefficient and lithology for oil and gas reservoirs. In the paper, the situations are researched respectively and the formula is compared with the classical Gassmann s formula.