Quantitative characterizations of anisotropic dynamic properties in organic-rich shale with different kerogen content  

作　　者：Jian-Yong Xie Yan-Ping Fang Xing-Hua Wu Jian'er Zhao Jun-Cheng Dai Jun-Xing Cao Ji-Xin Deng 

机构地区：[1]State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation,Chengdu University of Technology,Chengdu,610059,Sichuan,China [2]Key Lab of Earth Exploration&Information Techniques of Ministry of Education,Geophysical Institute,Chengdu University of Technology,Chengdu,610059,Sichuan,China [3]PetroChina Southwest Oil&Gasfield Company,Chengdu,610017,Sichuan,China

出　　处：《Petroleum Science》2024年第2期855-865,共11页石油科学（英文版）

基　　金：supported by the National Natural Science Foundation of China(42004112,42274175,42030812,41974160);Natural Science Foundation of Sichuan Province(2023NSFSC0764)。

摘　　要：Understanding the quantitative responses of anisotropic dynamic properties in organic-rich shale with different kerogen content(KC)is of great significance in hydrocarbon exploration and development.Conducting controlled experiments with a single variable is challenging for natural shales due to their high variations in components,diagenesis conditions,or pore fluid.We employed the hot-pressing technique to construct 11 well-controlled artificial shale with varying KC.These artificial shale samples were successive machined into prismatic shape for ultrasonic measurements along different directions.Observations revealed bedding perpendicular P-wave velocities are more sensitive to the increasing KC than bedding paralleling velocities due to the preferential alignments of kerogen.All elastic stiffnesses except C_(13)are generally decreasing with the increasing KC,the variation of C_(1) and C_(33)on kerogen content are more sensitive than those of C_(44)and C_(66).Apparent dynamic mechanical parameters(v and E)were found to have linear correlation with the true ones from complete anisotropic equations independent of KC,which hold value towards the interpretation of well logs consistently across formations,Anisotropic mechanical parameters(ΔE and brittlenessΔB)tend to decrease with the reducing KC,withΔB showing great sensitivity to KC variations.In the range of low KC(<10%),the V_(P)/V_(S) ratio demonstrated a linearly negative correlation with KC,and the V_(P)/V_(S) ratio magnitude of less than 1.75may serve as a significant characterization for highly organic-rich(>10%)shale,compilation of data from natural organic rich-shales globally verified the similar systematic relationships that can be empirically used to predict the fraction of KC in shales.

关 键 词：Elastic properties Organic shale ANISOTROPY Kerogen content Physical modeling 

分 类 号：TE311[石油与天然气工程—油气田开发工程]