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

作　　者：熊健[1] 朱梦渊 李文苗[2] 魏晋锋 刘向君[1] 梁利喜[1] 林思邑 XIONG Jian;ZHU Mengyuan;LI Wenmiao;WEI Jinfeng;LIU Xiangjun;LIANG Lixi;LIN Siyi(State Key Laboratory of Oil&Gas Reservoir Geology and Exploitation//Southwest Petroleum University,Chengdu,Sichuan 610500,China;Xinglongtai Oil Production Plant,PetroChina Liaohe Oilfield Company,Panjin,Liaoning 240100,China)

机构地区：[1]油气藏地质及开发工程全国重点实验室·西南石油大学 [2]中国石油辽河油田公司兴隆台采油厂

出　　处：《天然气工业》2023年第12期14-24,共11页Natural Gas Industry

基　　金：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)。

摘　　要：关于高温导致岩石孔隙结构和物理参数变化的研究成果较多,但研究的岩石岩性单一,且对不同岩性岩石受热激励后物理性质变化规律、差异机制等方面的研究还不深入。为此,以四川盆地上三叠统须家河组致密砂岩和泥岩、下志留统龙马溪组页岩为研究对象,通过室内实验,研究了高温作用下不同岩性岩石孔隙度、渗透率和声波速度的变化规律,并讨论了不同岩性岩石动态弹性参数、裂隙密度、损伤系数随温度变化的规律。研究结果表明:①不同岩性岩石阈值温度存在差异,其中砂岩为500℃,页岩为400℃,泥岩为300℃;②随着温度增加,不同岩性岩石表面颜色逐渐发生变化,宏观体积逐渐增大,质量和密度逐渐减小,有机碳含量是影响页岩表观颜色的主控因素;③不同岩性岩石孔隙度、渗透率、裂隙密度、损伤系数随温度增加而增大,而声波速度、弹性模量、体积模量、剪切模量等弹性参数呈减小趋势;④随着温度增加,页岩时域信号振幅下降,频域图主频逐渐向低频部分偏移,岩石孔隙结构变化程度增加;⑤不同岩性岩石受热初期质量损失受到黏土矿物影响较大,而高温时受到碳酸盐矿物含量影响较大,碳酸盐矿物含量对孔隙度增大呈积极作用,石英含量对渗透率增大起积极作用,即岩石石英、碳酸盐矿物含量越高,高温作用后岩石物性改善效果越好。结论认为,高温对岩石的物理特性影响程度主要取决于岩石自身的矿物组分,研究结果对原位加热改性技术在储层增渗可行性研究有一定的参考价值。There are many research results on the changes in pore structur es 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

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 

分 类 号：P618.13[天文地球—矿床学]