稠油油藏双水平井SAGD生产电预热模型

摘要

There are two preheating methods for steam assisted gravity drainage(SAGD),namely the steam circulation method and electric preheating method. Compared with the steam circulation method,reservoir heterogeneity has a smaller influence on the electric preheating method and the formation nearby horizontal wells can be heated evenly. Therefore,the viscosity of oil is reduced and flowing capacity is improved. A mathematical model for SAGD electric preheating method is built and solved analytically. According to the special well pattern,the superposition principle is employed to deal with the multi-well interference problem. Meanwhile,variable electric power injection situation is handled. Temperature distribution at different time is obtained with the new model. The preheating time can be predicted at a given electric power injection mode. The research shows that in the case of constant total electric energy,increasing the electric power gradually in preheating is the best injection method and the temperature between wells rises higher than any other injection methods.%双水平井SAGD技术的预热方式有两种：蒸汽循环预热和电加热。与蒸汽循环预热方法相比，地层的非均质性对电加热方法影响较小。电加热能够比较均匀地预热近井周围地层，降低稠油黏度提高流动能力，保证蒸汽顺利注入地层。建立了双水平井SAGD电预热模型，并对模型进行求解。针对SAGD独特的布井方式，利用叠加原理处理多井干扰问题；并且对变功率注入的情况进行了分析。利用该模型可以求得任意时刻地层中各点温度分布；同时，给定加热功率和原油被加热的温度可以确定预热的时间。研究结果表明，在总的注入热量保持不变的情况下，预热过程中逐步增加热功率可以获得最佳的预热效果。