急剧冷却作用下高温岩石细观损伤与增渗机制研究  

Study on meso damage and seepage enhancement mechanism of high temperature rocks under rapid cooling

作　　者：张乐[1] 张伟[2,3] 贺甲元[1] 郭天魁[4] 曲占庆[4] 牟雪[2] ZHANG Le;ZHANG Wei;HE JiaYuan;GUO TianKui;QU ZhanQing;MOU Xue(Sinopec Petroleum Exploration and Production Research Institute,Beijing 100083,China;College of Energy and Mining Engineering,Shandong University of Science and Technology,Qingdao 266590,China;New-Energy Development Center of Shengli Oilfield,Sinopec,Dongying 257001,China;College of Petroleum Engineering,China University of Petroleum(East China),Qingdao 266580,China)

机构地区：[1]中国石化石油勘探开发研究院,北京100083 [2]山东科技大学能源与矿业工程学院,青岛266590 [3]中国石化胜利油田新能源开发中心,东营257001 [4]中国石油大学(华东)石油工程学院,青岛266580

出　　处：《地球物理学进展》2022年第2期551-560,共10页Progress in Geophysics

基　　金：国家自然科学基金项目(42102338);山东省自然科学基金项目(ZR2020QE115);中国石化科技部项目(P19035)联合资助.

摘　　要：干热岩储层改造与开发中不可避免地存在低温流体对高温岩石的冷冲击.首先分析了不同岩样升温过程的渗透率演化,随后开展600℃内急剧冷却前后渗透率、细观结构损伤和岩石力学性能测试试验,最后基于THM-D耦合开展了急剧冷却作用下高温岩石损伤数值模拟,探讨急剧冷却作用下高温岩石的细观损伤与增渗机制.结果表明:急剧冷却处理温度升高,岩石损伤加剧、渗透能力增加、力学性能降低;岩石矿物组成非均质性越强、矿物颗粒几何形状越不规则、杨氏模量越大、抗拉抗压强度越小均有利于岩石发生热致裂;高温岩石受冷冲击,低温诱导热应力作用于岩石产生拉伸破坏,低温流体流入致裂裂隙形成新的温度梯度,随着岩石换热低温诱导热应力先增加后降低.The cold impact of low temperature fluid on hot rock is unavoidable in the construction and development of hot dry rock.Firstly,for different kind of rock samples the permeability evolution in temperature rise process was discussed;then the permeability,meso damage and rock mechanical properties before and after the rapid cooling within 600℃were tested;lastly,based on the THMD coupling,the damage simulation of hot rock under rapid cooling is conducted.This study is intended to reveal the mechanism of meso damage and permeability enhancement of hot rock under rapid cooling.The results indicate that:with the increase of cooling treatment temperature,the damage of rock is aggravated,the permeability is increased and the mechanical properties are reduced;the stronger heterogeneity of rock composition,the more irregular geometrical shape of mineral particles,the larger Young's modulus of rock and the smaller tensile and compressive strength are all beneficial to the thermal cracking;when the hot rock subjected to cold shock,cryogenic induced thermal stress act on rock by tensile stress and then cause tensile failure.Subsequently,the cryogenic fluid flows into these cracks and forms the new temperature gradient.With the heat exchange of rocks,the cryogenic induced thermal stress tends to increase first and then decrease.

关 键 词：高温岩石 急剧冷却 细观损伤 力学性能 增渗机制 

分 类 号：P314[天文地球—固体地球物理学]