酸液对灰岩力学性质影响的机制研究  

MECHANISM STUDY OF ACID ON MECHANICAL PROPERTIES OF LIMESTONE

作　　者：何春明[1] 郭建春[1] 

机构地区：[1]西南石油大学油气藏地质及开发工程国家重点实验室,四川成都610500

出　　处：《岩石力学与工程学报》2013年第S2期3016-3021,共6页Chinese Journal of Rock Mechanics and Engineering

基　　金：国家自然科学基金资助项目(51074138);国家重大科技专项(2011ZX05013003);四川省青年科技创新研究团队资助计划(2011JTD0018)

摘　　要：通过岩芯静态溶蚀试验、岩芯动态流动试验并结合三轴力学测试及岩芯微观结构分析,从宏观和微观角度研究不同酸液对岩石力学强度破坏问题。动静态溶蚀试验表明,胶凝酸以点状溶蚀为主,而变黏酸主要以表面溶蚀为主。三轴力学测试表明,胶凝酸溶蚀后岩石抗压强度降低18%,杨氏模量降低26%,高于变黏酸对岩石力学强度的破坏。应力–应变曲线显示反应后岩芯的压实致密过程持续时间较长,岩芯表现出更强的塑性。扫描电镜观察发现,胶凝酸反应后在岩芯内部形成大量酸蚀孔洞,而变黏酸主要以均匀溶蚀为主,对岩芯内部结构破坏较小,酸液对岩芯内部溶蚀结构的差异是产生力学强度差异的根本原因。对于高闭合应力储层,在酸液选择方面应更多考虑酸液对岩石力学强度的破坏,选择控制滤失能力强的酸液体系。Through systematic experiments test includes static rock dissolution experiments,dynamic rock flow experiments,triaxial mechanical tests and microstructure analysis of rocks,the mechanical strength reduction of limestone reacting with different acids were studied from the macroscopic and microcosmic perspective. Static and dynamic dissolution experiments showed that gelled acid could create many small solution caves on the rock face, while viscosity acid was mainly of surface dissolution. triaxial mechanical test indicated that the compression strength of rock was reduced by 18%,and Young′s modulus by 26%after reaction with gelled acid,which was much larger than the mechanic strength reduction that dissolved by viscosity acid. Stress-strain curve showed that the compaction densification process after reaction continued for a long time,and showing more plastic behavior. Scanning electron microscope observation indicated that there were many small dissolution holes in the rock after reacting with gelled acid,while the viscosity acid was mainly of uniform dissolution,which has little damage to the internal structure of rock. The difference of dissolution structure for different acids maybe the fundamental reason for the difference of mechanical strength. For high closure stress reservoirs,it should be care more about the mechanical strength reduction that caused by acid-rock reaction,which means to choose leak off-control acids.

关 键 词：岩石力学 酸压 灰岩 三轴力学测试 扫描电镜 

分 类 号：TU45[建筑科学—岩土工程]