摘要：Quantitatively assessing attenuation and dispersion of elastic-wave velocities in partially saturated reservoir is difficult because of its sensitivity to fluid distribution. We conducted experiments on homogeneous Indiana limestone samples, partially saturated by two methods: drying and imbibition which lead to different fluid distribution for a given saturation. Forced oscillations (from 0.004 to 100 Hz) and ultrasonic (1 MHz) measurements were done under confining pressure to measure the change of elastic moduli with frequency and their attenuation. Our measurements show that compressional (P-)velocities are strongly sensitive to the sample's saturation method. For high saturations (above 80%), obtained by drainage, compressional velocities are frequency dependent, and clear peaks of attenuation can be observed. However, at the same saturations obtained by imbibition, no dispersion or attenuation is observed. In addition, shear velocities show little variation with frequency, saturations, and fluid distribution. The dispersion and attenuation of P-velocities are shown to be influenced by the pore fluid distribution, which was investigated using micro-computer-assisted tomographic (CT) scans. Furthermore, a numerical model developed within the framework of poroelasticity's theory predicts well the experimental results, using the fluid distribution obtained from CT as an input. Our results show that the velocity dispersion was related to wave-induced fluid flow at mesoscopic scale controlled by the geometry and distribution of the gas patches.

关键字：partial saturation; attenuation; dispersion; seismic properties; WIFF; mesoscopic flow

ISSN号：2169-9313

卷、期、页：卷: 127期: 5

发表日期：2022-05-11

影响因子：3.847700

期刊分区（SCI为中科院分区）：二区

收录情况：SCI（科学引文索引印刷版）,地学领域高质量科技期刊分级目录（国外T1）,SCIE（科学引文索引网络版）

发表期刊名称：JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH

参与作者：孙超,Fortin, Jerome,Borgomano, Jan V. M.,Bultreys, Tom,Cnudde, Veerle

第一作者：王尚旭,唐跟阳

论文类型：期刊论文

论文概要：孙超,Fortin, Jerome,Borgomano, Jan V. M.,王尚旭,唐跟阳,Bultreys, Tom,Cnudde, Veerle，Influence of Fluid Distribution on Seismic Dispersion and Attenuation in Partially Saturated Limestone，JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH，2022，卷: 127期: 5

论文题目：Influence of Fluid Distribution on Seismic Dispersion and Attenuation in Partially Saturated Limestone