天然气工业2023，Vol.43Issue(12)：14-24,11.DOI:10.3787/j.issn.1000-0976.2023.12.002
高温作用下不同岩性岩石物理特性的演化规律
Evolution law of physical properties of rocks with different lithologies under high temperature
摘要
Abstract
There are many research results on the changes in pore structures and physical parameters of rocks caused by high temperature,but the rock lithology in those studies is single,and the changes in physical properties and differential mechanisms of rocks with different lithologies after thermal stimulation are less researched.In this paper,the change patterns of porosity,permeability and acoustic velocity of rocks with different lithologies under high temperature are studied by performing laboratory experiments on the tight sandstone and mudstone of the Upper Triassic Xujiahe Formation and the shale of the Lower Silurian Longmaxi Formation in the Sichuan Basin.In addition,the relationships of dynamic elastic parameters,fracture density and damage coefficient of rocks with different lithologies vs.temperature are discussed.And the following research results are obtained.First,rocks with different lithologies are different in the threshold temperature,with sandstone at 500 ℃,shale at 400 ℃,and mudstone at 300 ℃.Second,as the temperature increases,the surface color of rocks with different lithologies gradually changes,the macroscopic volume gradually increases,and the quality and density gradually decrease.The total organic carbon(TOC)is the main factor affecting the apparent color of shale.Third,with the increase of temperature,the porosity,permeability,fracture density and damage factor of rocks with different lithologies increase,while the elastic parameters such as acoustic velocity,elastic modulus,bulk modulus and shear modulus show a decreasing trend.Fourth,as the temperature increases,the time-domain signal amplitude of the shale decreases,and the main frequency of the frequency-domain map gradually shifts towards the low-frequency part,resulting in an increase in the change degree of rock pore structure;Fifth,the quality loss of rocks with different lithologies is affected more by clay minerals during the initial heating period,but by the content of carbonate minerals under high temperatures.The content of carbonate minerals has a positive effect on the increase of porosity,while the content of quartz has a positive effect on the increase of permeability.The higher the content of quartz and carbonate minerals in the rock,the better the improvement effect of petrophysical properties after high-temperature treatment.In conclusion,the influence degree of high temperature on the petrophysical properties is mainly dependent on the mineral components of rocks themselves.The research results have a certain reference value for the feasibility study of in-situ heating modification technology in reservoir permeability enhancement.关键词
高温/不同岩性/基础物性/声波特性/动态弹性参数/裂隙密度/损伤系数Key words
High temperature/Different lithologies/Basic physical properties/Acoustic characteristics/Dynamic elastic parameters/Fracture density/Damage coefficient引用本文复制引用
熊健,朱梦渊,李文苗,魏晋锋,刘向君,梁利喜,林思邑..高温作用下不同岩性岩石物理特性的演化规律[J].天然气工业,2023,43(12):14-24,11.基金项目
国家自然科学基金项目"陆相页岩油储层热-化-力耦合作用诱导致裂与增渗机理研究"(编号:42272190)、西南石油大学第22期课外开放实验重点项目"温度作用下页岩岩石物理性质的变化规律研究"(编号:2022KSZ02018). （编号:42272190）
