摘要：Gas shale formation with extremely low porosity and permeability can only be developed economically by using a fracturing treatment to form spatial hydraulic fracture networks. Shearing slip is an important factor during fracture network formation and is controlled by the frictional strength of the fracture surface. A series of experimental studies were performed on shale's frictional coefficient, sliding behaviors and compressive shearing strength. The results showed that (1) normal stress has little effect on the sliding frictional coefficient, but the sliding mode is obviously changed with normal stress. Higher normal stress induces a smoother sliding. (2) Different shale exhibited different friction properties. When the clay content in shale is high enough (higher than 35% in this paper) and most of the clay minerals are smectite or an IBS mixed layer, a lower frictional coefficient will be observed (less than 0.6). Meanwhile, the shale's frictional coefficient was more sensitive to water. Slicicwater with a resistance reducer additive can reduce the frictional coefficient to 0.36. (3) Absorbed water (e.g., by capillary force or osmotic pressure) inside the shale can activate the natural cracks in the shale and induce micro-slip under compressive stress conditions. The energy release process will be dispersively distributed, and complex fracture networks tend to form. These results are helpful in revealing the mechanisms of fracture networks formation in shale reservoirs under the combined effects of stress, fracturing fluid, and natural fractures. (C) 2016 Elsevier B.V. All rights reserved.

关键字：Gas shale friction Clay minerals content Fluid effect Compressive shear failure

ISSN号：1875-5100

卷、期、页：卷: 33 页: 153-161

发表日期：2016-07-01

期刊分区（SCI为中科院分区）：二区

收录情况：SCIE（科学引文索引网络版）,ESI（基本科学指标数据库）,EI（工程索引）

发表期刊名称：JOURNAL OF NATURAL GAS SCIENCE AND ENGINEERING

参与作者：McClatchey, Nathaniel J.

通讯作者：Wang, Jianbo,Wang, Daobing,Meng, Fanbao,Chen, Jianguo

第一作者：闫伟,葛洪魁,王小琼

论文类型：期刊论文

论文概要：闫伟,葛洪魁,Wang, Jianbo,Wang, Daobing,Meng, Fanbao,Chen, Jianguo,王小琼,McClatchey, Nathaniel J.，Experimental study of the friction properties and compressive shear failure behaviors of gas shale under the influence of fluids，JOURNAL OF NATURAL GAS SCIENCE AND ENGINEERING，2016，卷: 33 页: 153-161

论文题目：Experimental study of the friction properties and compressive shear failure behaviors of gas shale under the influence of fluids