煤田地质与勘探2024，Vol.52Issue(6)：12-20,9.DOI:10.12363/issn.1001-1986.23.11.0773
超临界CO2脉动压裂-渗流耦合试验系统研制与应用
Development and application of a supercritical CO2 pulsed fracturing-seepage coupling test system
摘要
Abstract
[Objective]To effectively enhance the extraction effects of coalbed methane(CBM),this study proposed a novel approach for fracturing coals(rocks)using pulsation of supercritical carbon dioxide(CO2)by combining pulsed fracturing with supercritical CO2 fracturing.[Methods]A true triaxial test system coupling supercritical CO2 pulsed frac-turing with seepage was independently developed,and its primary structure,characteristics,and functions were elucid-ated.Then,the supercritical CO2 pulsed fracturing-seepage/acoustic emission monitoring tests under true triaxial condi-tions were conducted in the laboratory.The test system,controlling the triaxial stress by combining an independent servo system with a central digital system and achieving pulsed pressurization using a dual pump with constant speed and pres-sure,features high precision,true triaxiality,and resistance to high temperature,pressure,and stress and covers the whole process.[Results and Conclusions]The results indicate that the true triaxial test system that couples supercritical CO2 pulsed fracturing with seepage can achieve effective pulsed fracturing.Using supercritical CO2 pulsed fracturing,the permeability of coals can increase by two to nine times,manifesting a pronounced exponential growth.During the acoustic emission-supercritical CO2 pulsed fracturing,new fracture channels were formed in coals.These channels pen-etrated directly from the center of the fractured pores to the coal surface,with supercritical CO2 being observed ejecting directly from coals.Therefore,supercritical CO2 pulsed fracturing plays a certain role in propagating and connecting fractures,effectively improving CBM extraction.The findings of this study provide certain test support for reinforcing the permeability enhancement technology of deep,low-permeability coal seams and offer practical guidance for field CO2 fracturing engineering.关键词
超临界CO2/脉动压裂/真三轴/渗流特性/声发射Key words
supercritical CO2/pulsed fracturing/true triaxiality/seepage characteristic/acoustic emission分类
矿业与冶金引用本文复制引用
刘佳佳,张云龙,聂子硕,高志扬,许文松..超临界CO2脉动压裂-渗流耦合试验系统研制与应用[J].煤田地质与勘探,2024,52(6):12-20,9.基金项目
国家自然科学基金面上项目(52074106) （52074106）
河南省优秀青年科学基金项目(232300421061) （232300421061）
河南理工大学创新型科研团队项目(T2023-3) （T2023-3）
深部煤矿采动响应与灾害防控国家重点实验室开放基金项目(SKLMRDPC22KF11) （SKLMRDPC22KF11）
瓦斯灾害监控与应急技术国家重点实验室开放基金项目(2021SKLKF01) （2021SKLKF01）
