钻井过程中井壁热应力数值模拟

井壁热应力对于井壁稳定性、水力压裂、水泥环胶结强度、热采套管的损害等都有影响。文中根据热弹性力学理论，将地层假设成均匀连续弹性介质，推导建立了井壁热应力的数学模型，并结合井内流体流动和静止过程中井壁温度场的变化，采用数值计算方法得出了井壁热应力的瞬态分布，包括井壁热应力随井深、径向距以及时间的变化。文中的理论模型和计算结果对于研究由于热应力引起的现场问题都具有指导意义。

NUMERICAL SIMULATION FOR THERMAL STRESS NEAR WELLBORE DURING DRILLING

The wellbore stability, fracturing, cementing strength, and casing failure during thermal recovery are affected by thermal stress. In this paper based on the thermoelastic mechanics, the mathematical models for thermal stress have been derived through assuming the formation near the wellbore as uniform and continuous elastic medium. The numerical solutions for transient thermal stress near hole are computed by means of the temperature distribution during mud circulation and no circulation. The plots of thermal stress versus depth, radius, and time have been obtained. The theoretical models and computed results are of guiding significance for the study of the field problems caused by thermal stress.