P-wave velocity prediction in porous medium with liquid-pocket patchy saturation |
| |
Authors: | Jiawei Liu Weitao Sun Jing Ba |
| |
Institution: | 1. Zhou Pei-Yuan Center for Applied Mathematics, Tsinghua University, Beijing 100084, China;
2. Department of Computational Geophysics, Xi'an Jiaotong University, Xi'an 710049, China |
| |
Abstract: | It becomes increasingly clear that non-uniform distribution of immiscible fluids in porous rock is particularly relevant to seismic wave dispersion. White proposed a patchy saturation model in 1975, in which spherical gas pockets were located at the center of a liquid saturated cube. For an extremely light and compressible inner gas, the physical properties can be approximated by a vacuum with White's model. The model successfully analyzes the dispersion phenomena of a P-wave velocity in gas-watersaturated rocks. In the case of liquid pocket saturation, e.g., an oil-pocket surrounded by a water saturated host matrix, the light fluid-pocket assumption is doubtful, and few works have been reported in White's framework. In this work, Poisson's ratio, the bulk modulus, and the effective density of a dual-liquid saturated medium are formulated for the heterogeneous porous rocks containing liquid-pockets. The analysis of the difference between the newly derived bulk modulus and that of White's model shows that the effects of liquid-pocket saturation do not disappear unless the porosity approaches zero. The inner pocket fluid can no longer be ignored. The improvements of the P-wave velocity predictions are illustrated with two examples taken from experiments, i.e., the P-wave velocity in the sandstone saturated by oil and brine and the P-wave velocity for heavy oils and stones at different temperatures. |
| |
Keywords: | White's model liquid pocket P-wave dispersion porous medium |
本文献已被 SpringerLink 等数据库收录! |
| 点击此处可从《应用数学和力学(英文版)》浏览原始摘要信息 |
| 点击此处可从《应用数学和力学(英文版)》下载免费的PDF全文 |
|