随机介质固热耦合模型与高温岩体地热开发人工储留层二次破裂数值模拟

RANDOM NON-HOMOGENEOUS SOLID-HEAT COUPLED MODEL AND NUMERICAL SIMULATIONS OFSECOND FRACTURING FOR MAN-MADE-RESERVE STRATUM IN HDR

在高温岩体地热开发中,针对岩石矿物组分及其分布的不同,将热膨胀系数作为随机介质,在平面应变模型下,建立了随机介质的温度场和应力场耦合数学模型,并推导了该耦合问题的有限元格式。在正态分布、韦伯分布 2 种随机分布下,进行了高温岩体地热开发数值模拟试验,揭示了岩体温度场和应力场的特征及变化规律。研究表明,热膨胀系数的概率分布形式对岩体热破裂规律有重要影响。

In the hot dry rock (HDR) extraction, according to the rock mineral compositions and different distributions, the thermal dilatability is considered as random medium. With the plane stain model, the random non-homogeneous solid-heat coupled mathematical model and stress field are established, and the FEM coupling is achieved. With the two random distributions of Gauss distribution and Weibull distribution, based on a variety of numerical experiments of the HDR extraction, the characteristics and laws of temperature, stress fields, and the derived results reveal that the random distributions of thermal dilatability have great influences on thermal fracture law, the relationship between temperature and time, the relationship between crack ratio and time, and the plane maximum main stress distribution.