摘要
低透煤层液态CO_(2)压裂兼具裂隙改造和驱替置换的双重瓦斯强化抽采作用,是一项易于与其他技术联合使用,具有规模化应用潜力的增透技术。提出了低透煤层液态CO_(2)压裂增透理论体系及成套技术框架;依据应力叠加原理和最大拉应力准则,考虑压注过程液态CO_(2)相态变化和低黏强渗透性,建立了液态CO_(2)压裂起裂压力确定模型;以I型断裂准则为裂缝扩展判别条件,建立了恒定注液流量下压裂孔口压力与裂缝扩展距离之间的量化表征关系,阐明了注液压力、压裂液黏度、裂缝产状对裂缝扩展的影响规律。依此为基础,提出了决定液态CO_(2)压裂增透煤层成套装备性能的4个关键参数及其计算方法,研制了国内首套井下压裂增透成套装备,研发了压裂增透施工工艺,分别在淮南矿区、彬长矿区等进行了推广应用。
Liquid CO_(2)fracturing in low-permeability coal seams has dual gas-enhanced drainage effects of fracture reconstruction and displacement.It is a permeability enhancement technology that is easy to be used in combination with other technologies and has the potential for large-scale application.This paper proposes a theoretical system and a complete set of technical framework for fracturing and permeability enhancement of low-permeability coal seam with liquid CO_(2);according to the principle of stress superposition and the maximum tensile stress criterion,a model for determining the initiation pressure of liquid CO_(2)fracturing was established considering the change of phase state and low viscosity and strong permeability of liquid CO_(2)during the injection process;taking type I fracture criterion as the discriminant condition of fracture propagation,the quantitative characterizing relationship between fracturing orifice pressure and fracture propagation distance under constant fluid injection flow was established,and the influence law of fluid injection pressure,fracturing fluid viscosity and fracture occurrence on fracture propagation was clarified.On this basis,the four key parameters and their calculation methods to determine the performance of the complete set of equipment for liquid CO_(2)fracturing and permeability improvement in coal seam were proposed,the first complete set of equipment for underground fracturing and permeability improvement in China was developed,and the construction technology of fracturing and permeability improvement was developed,which was applied in Huainan Mining Area and Binchang Mining Area respectively.
作者
樊世星
文虎
童校长
吴学明
陈建
张铎
FAN Shixing;WEN Hu;TONG Xiaozhang;WU Xueming;CHEN Jian;ZHANG Duo(College of Safety Science and Engineering,Xi’an University of Science and Technology,Xi'an 710054,China;Key Laboratory of Western Mine Exploitation and Hazard Prevention,Ministry of Education,Xi’an University of Science and Technology,Xi'an 710054,China;Coal Mining Company Limited,Huaihe Energy Holding Group,Huainan 232001,China;Shaanxi Binchang Mining Group Co.,Ltd.,Xianyang 712046,China)
出处
《煤矿安全》
CAS
北大核心
2022年第10期80-88,共9页
Safety in Coal Mines
关键词
低透煤层
液态CO_(2)
压裂增透
成套技术
瓦斯抽采
low permeability coal seam
liquid CO_(2)
permeability enhancement by fracturing
complete set of equipment
gas drainage
