摘要：The wave velocity and wave velocity anisotropy of four groups of tight sandstones and shales from different areas were studied in the laboratory. Combined with SEM analysis and wave velocity stress sensitivity tests, the main influencing factors of anisotropy of tight sandstone and shale were analyzed. Results show that (1) bedding and microcracks are the main factors leading to the anisotropy of tight sandstone, while the anisotropy of shale is mainly caused by the directional development of mineral composition. The anisotropy of tight sandstone used in this study is stronger than that of shale. (2) The wave velocity of the rock parallel to the formation is higher than that of the rock perpendicular to the formation, and the ultrasonic velocity increases with the growing stress. (3) The variation of wave velocity anisotropy with stress can be divided into two stages. One is the stress-related anisotropy weakened with the increase of stress, which is related to the directional arrangement of microcracks. The other is the matrix-related anisotropy does not changing with the stress, which is related to the mineral composition in the matrix. (4) These two kinds of anisotropy are verified by the crack porosity obtained using volume strain and mineral content. The stress-related anisotropy is directly proportional to the crack density, and the matrix-related anisotropy is linearly correlated with the clay mineral content. (5) According to the two stages of wave velocity anisotropy changing with stress, the influence of microcracks and matrix on rock anisotropy can be quantitatively distinguished. These research results are of great significance to understanding the fracture propagation in hydraulic fracturing. ? 2021, Science Press. All right reserved.

ISSN号：0001-5733

卷、期、页：卷64期12：4239-4251

发表日期：2021-12-10

影响因子：0.811100

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）,EI（工程索引）,SCIE（科学引文索引网络版）

发表期刊名称：Acta Geophysica Sinica

参与作者：王文文

通讯作者：张茜

第一作者：王小琼,葛洪魁

论文类型：期刊论文

论文概要：王小琼,葛洪魁,王文文 ,张茜，Experimental study on stress-related and matrix-related anisotropy in tight reservoirs，Acta Geophysica Sinica，2021，卷64期12：4239-4251

论文题目：Experimental study on stress-related and matrix-related anisotropy in tight reservoirs