地热开发温度应力裂缝参数计算方法及影响因素分析

利用低温流体诱导温度应力裂缝开发地热资源在地热藏开发中有广泛应用。基于温度应力产生原因的分析,构建了地层岩石温度应力裂缝延伸二维模型,确定了温度应力裂缝起裂条件及温度应力裂缝延伸长度随时间的变化函数,并对影响温度应力裂缝起裂及延伸的因素进行了分析。结果表明,建立的模型与数值模拟结果有较好的一致性。岩石温度应力裂缝随着时间延长而不断延伸,但其造缝效率随着时间延长有缓慢下降趋势。基于温度应力裂缝影响因素分析结果,对温度应力高效造缝提出了建议。

Solving method of thermal stress fracture parameter and influence factor analysis in geothermal reservoir

Low temperature fluid induced thermal stress cracks is widely used in the development of geothermal reservoirs to extract geothermal resources. Based on the analysis of the cause of thermal stress, a two-dimensional model of thermal stress crack extension in formation was built and the temperature stress crack initiation conditions and the variation function of the temperature stress crack extension length with time were determined. The factors affecting the temperature stress crack initiation and extension were also analyzed. The results show that the model is in good agreement with the numerical simulation results. Temperature stress crack of rock extends continuously with time, but its efficiency decreases slowly with time. According to the analysis results of the influencing factors of temperature stress cracks, suggestions for efficient temperature stress cracking were put forward.