考虑钻井液流动阻力与钻柱旋转的井筒瞬态传热新模型

为了分析钻井液流动阻力与钻柱旋转对井筒温度的影响,文中基于能量守恒定律,考虑流动阻力产生的摩擦热能与钻柱旋转产生的旋转动能,建立了井筒瞬态传热新模型。该模型的计算值比Yang数值模型和Al-Saedi解析模型的计算值高,更接近井底实际温度。实例井计算结果表明:相比于流动阻力,钻柱旋转对井口温度和井底温度的影响较大;流动阻力与钻柱旋转对上部井段温度的影响不大,但随着井深的增加,影响逐渐加剧;随着钻柱转速与钻井液排量的增加,环空温度不断增大。

Transient wellbore heat transfer new model considering drilling fluid flow resistance and drillstring rotation

In order to analyze the influence of drilling fluid flow resistance and drillstring rotation on wellbore temperature,the transient wellbore heat transfer new model was established based on the law of conservation of energy and considering the frictional heat energy generated by flow resistance and the rotational kinetic energy generated by drillstring rotation.The calculation of this model are higher than those of Yang numerical model and Al-Saedi analytical model,and closer to the actual bottomhole temperature.The calculation results of an example well show that the effect of drillstring rotation on wellhead and bottom hole temperature is greater than that of flow resistance.Flow resistance and drillstring rotation have little influence on the temperature of wellhead and upper well section,but with the increase of well depth,the influence becomes more and more serious,especially in open hole section.In addition,with the increase of drillstring rotation speed and drilling fluid displacement,annular temperature increases continuously.