钻探工程2024，Vol.51Issue(5)：85-92,8.DOI:10.12143/j.ztgc.2024.05.010
基于扩展有限元的现场尺度水力裂缝扩展机制模拟研究
Simulation research of field-scale hydraulic fracture extension mechanism based on XFEM
摘要
Abstract
Hydraulic fracturing of hot dry rock(HDR)reservoirs to form a complex network of seams is essential for the construction of enhanced geothermal systems(EGS).In order to deeply understand the mechanism of hydraulic fracture extension in HDR reservoirs and reveal the influence of engineering and geological parameters on hydraulic fracture extension,in this paper,a HDR reservoir in the Gonghe Basin of Qinghai Province is taken as the research object,and based on the extended finite element method(XFEM)numerical simulation software ABAQUS,a field-scale HDR reservoir model is established to realize the thermo-hydro-mechanical coupling and to analyze the extension mechanism of the hydraulic fracture.The results show that:(1)In the normal fracture-type stress state,the crack undergoes a very obvious turning toward the Z-axis,in the strike-slip-type stress state,the crack expands mainly along the horizontal direction with a slight tendency to turn toward the Z-axis,and in the thrust-type stress state,the crack expands along the horizontal direction.(2)With the increase of elastic modulus crack initiation pressure decreases,the injection pressure of crack extension also decreases;the larger the elastic modulus the earlier the crack initiation time;the larger the Poisson ratio the greater the rupture pressure of hydraulic cracks;the rupture pressure as a whole shows a normal fracture-type>strike-slip-type>thrust-type.(3)The hydraulic fracture rupture pressure decreases with the increasing temperature,by about 2～3MPa or so,showing the same trend for all three stress states.This paper inriches the numerical simulation methods of hydraulic fracturing extention for HDR,the relavant research results can also provides technical supports for the prediction of the hydraulic fracturing extention and the influences affected by different perameters for HDR reservoirs.关键词
水力压裂/储层裂缝/干热岩/扩展有限元/现场尺度/热流固耦合Key words
hydraulic fracturing/reservoir fracture/hot dry rock/extended finite element method/field scale/thermo-hydro-mechanical coupling分类
能源科技引用本文复制引用
曹志成,陈秋,崔俊艳,解经宇,张卫强,蒋国盛..基于扩展有限元的现场尺度水力裂缝扩展机制模拟研究[J].钻探工程,2024,51(5):85-92,8.基金项目
国家自然科学基金项目(编号:42102353) （编号:42102353）
中国科协青年托举人才工程项目(编号:2023QNRC001) （编号:2023QNRC001）
中国矿业大学基本科研业务费项目——青年科技基金(编号:2023-00030) （编号:2023-00030）
