稠油蒸汽驱生产井闪蒸预测模型

摘要

Flash in steam flooding producers may result in problems of pump air lock, tubing and pump failure, fluid production decline and so on. The difficulty of flash prediction stays in calculation accuracy of bottom hole temperature and pressure. Models of wellbore temperature distribution, pressure distribution, and local pressure drop when fluids flowing through standing valve are established based on principles of heat transfer and fluid dynamics, and a flash prediction model of steam flooding producers is established combining with modified critical temperature - pressure curve of saturated steam of oil - water mixture. Flash in bottom hole and inside pump can be monitored in real time according to wellhead fluid production, water cut, temperature and hole structure parameters. Field application has proved that the flash prediction model can accurately forecast bottom hole flow regime.%稠油蒸汽驱生产井闪蒸会造成抽油泵气锁、油管及抽油泵损坏、产液量下降等问题.闪蒸预测的难点在于井底温度和压力计算的准确与否.根据传热学和计算流体力学建立了井筒温度分布模型、压力分布模型、液体流经抽油泵固定阀时的局部压降损失计算模型,结合修正的油水混合物饱和蒸汽临界温度-压力曲线,建立了稠油蒸汽驱生产井闪蒸预测模型.可以依据井口产液量、含水率、温度等生产参数及井身结构参数对井底及泵内闪蒸情况做到实时监测.现场应用证明闪蒸预测模型能对井底流体状态进行准确预测.