西南石油大学学报（自然科学版）2024，Vol.46Issue(2)：65-76,12.DOI:10.11885/j.issn.1674-5086.2023.09.02.01
超临界CO2对致密碳酸盐岩力学特性影响
Effect of Supercritical CO2 on Mechanical Properties of Tight Carbonate Rocks
摘要
Abstract
The supercritical CO2 fracturing has the characteristics of low fracture pressure and easy formation of complex fractures in tight carbonate rock,but the mechanical mechanism of the effect of supercritical CO2 on tight carbonate rocks is not clear.The physical properties,acoustic response,rock mechanical properties and fracture morphology of the tight dolomite samples from Majiagou Formation were studied by using the high temperature and high pressure supercritical CO2 saturated fluid method,namely the samples were immersed in supercritical CO2+formation water for different time.The results show that with the increase of soaking time,the dissolution pore size and the porosity and permeability of the rock sample increase due to chemical corrosion,and the corresponding acoustic velocity,dynamic and static rock mechanical parameters all decrease.When the soaking time is longer than 1.0 d,the physical property parameters of the rock sample increase and the mechanical strength decreases obviously.With the increase of soaking time,the fracture morphology of rock samples develops from single low angle shear joint to high angle shear joint,conjugate joint and shear and tension composite joint.In short fracturing time(≤ 1.0 d),the weak acid formed by supercritical CO2+formation water has limited deterioration degree to rock mechanical strength.关键词
致密碳酸盐岩/超临界CO2/前置酸压/力学强度/破裂形态Key words
tight carbonate rock/supercritical CO2/pre-acid fracturing/mechanical strength/fracture pattern分类
能源科技引用本文复制引用
苟波,王琨,李骁,詹立,刘超..超临界CO2对致密碳酸盐岩力学特性影响[J].西南石油大学学报（自然科学版）,2024,46(2):65-76,12.基金项目
国家自然科学基金(52374047,U21A20105) （52374047,U21A20105）
