注蒸汽开发稠油油藏中的井筒热损失分析

注蒸汽开发稠油油藏过程中，为了预测沿井深和随时间变化的蒸汽温度分布、干度分布和蒸汽压力分布、套管和地层温度分布，以及焖井、开井生产过程中温度、压力的变化，首先必须建立注入过程中的井筒-地层温度分布模型。而这一模型建立的基础是井筒热损失的计算分析。文中应用热传递基本理论，通过井筒内能量守恒定理建立起注蒸汽井井筒热损失计算预测模型，重点分析了井筒总传热系数Uto和注汽速度对井筒热损失和井底蒸汽干度的影响，对注蒸汽开发稠油油藏有一定的指导作用。

ANALYSIS OF THE WELLBORE HEAT LOSS IN DEVELOPMENT HEAVY OIL RESERVOIR BY STEAM INJECTION

During the cyclic steam stimulation, the distribution of temperature directly affects the stimulation effect. Based on the calculation and analysis of the wellbore heat loss, it's necessary to establish the temperature distribution model of cyclic steam wellbore-stratum to predict the temperature distribution, dryness fraction distribution, the steam pressure distribution, the casing and formation temperature distribution, which are changing with the depth and the time. The temperature distribution model can effectively analyze the heat loss of wellbore during the cyclic steam stimulation. In the paper, based on fundamental tenet of heat transfer and the conservation laws of energy, establish the prediction models of calculation heat loss in steam injection well. It mainly analyses the impact of the over-all heat-transfer coefficient of the wellbore and the injection rate on the heat loss and the downhole dryness fraction. The study has an active value to direct the exploiting the heavy oil reservoir with injecting steam.