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1.前言稠油开采往往是通过向油藏注入高温高压蒸汽。油层通过吸收蒸油带进来的能量使稠油的粘度降低,从而增加原油的流动性能,使原油得以较顺利地开采。因此,研究油藏传热机理对合理利用蒸汽、经济有效地开采稠油具有十分重要的现实意义。注入油藏中的蒸汽主要是用来提高油层的温度,为此,一个重要的问题就是减少热能损失。而热能损失主要表现在①地面输汽管道热损失(向大气中热扩散);②井筒热损失(向井筒周围地层岩石热扩散);③损失于油藏中盖层和底层的能量;④采油带出的能量。在采油开发方案中我们常常要求③,④部分损失的能量最少,以保证油层得到的能量最多。较为完整的反映油藏传热的模型是根据原油开采中质量、能量传递过程所满足的质量、能量守情景主程和热传导方程建立起来的。它是求解一个非线性偏微发方程组的初边值问题。而这样的模型计算往往是复杂的,并且常常是不稳定的。因此,从稠油开采的角度,若能给出透用性的传热简化模型,无疑对稠油开采的预测及模拟都有较现实的意义。2.模型的建立通过计算地面输蒸汽管道和井筒的热损失,我们可以给出蒸汽在油层中的常规物性参
1. Introduction Heavy oil production is often through the injection of high temperature and pressure steam into the reservoir. The oil layer reduces the viscosity of heavy oil by absorbing the energy brought in by the steam oil, thereby increasing the flowability of crude oil and enabling the crude oil to be mined more smoothly. Therefore, studying the mechanism of heat transfer in reservoirs is of great practical significance for the rational utilization of steam and the economical and effective exploitation of heavy oil. The steam injected into the reservoir is mainly used to raise the temperature of the reservoir. Therefore, an important issue is to reduce the heat loss. The heat loss is mainly manifested in the following: 1) the heat loss of the ground-based steam pipe (thermal diffusion into the atmosphere); 2) heat loss from the wellbore (thermal diffusion to the rock around the wellbore); 3) the energy lost in the middle and bottom layers of the reservoir; Bring out the energy. In the oil recovery development program we often require ③, ④ part of the loss of the least energy to ensure that the reservoir get the most energy. A more complete model of reservoir heat transfer is based on the quality of the crude oil extraction, the quality of the energy transfer process, the main course of energy conservation and the heat conduction equation. It is the initial boundary value problem for solving a nonlinear partial differential equations. Such model calculations are often complex and often unstable. Therefore, from the point of view of heavy oil recovery, if a simplified heat transfer model is given, it is more realistic to predict and simulate heavy oil production. 2. Establishment of Model By calculating the heat loss from the steam pipe and the wellbore, we can give the general parameters of the steam in the reservoir