宾汉型稠油水平井产能模型探讨

Discussion on productivity model of horizontal wells in Bingham type heavy oil reservoir

由于内部形成的胶体结构,稠油流变特性一般比较复杂,属于一种典型的非牛顿流体——宾汉型流体。计算稠油油藏水平井产能时,人们往往忽略稠油的宾汉流变特性,导致计算过程中没有考虑由流体本身特性而带来的启动压力的影响,而使计算结果偏大,与现场应用产生一定差距,起不到指导现场实践的作用。在研究稠油流变特性的基础上,运用椭球型泄油模型,通过牛顿-柯特斯公式,推导了宾汉型流体水平井产能计算模型,并给出启动压力的确定方法。以实际油藏参数为例,计算对比了该模型与其他模型。研究结果表明,该模型产能计算结果小于其他模型,符合油田生产实际。

Owing to the inner gel texture of reservoir,the rheology property of heavy oil is generally complex and is a kind of typical non-Newton fluid,that is Bingham type fluid.When calculating the productivity of horizontal well in heavy oil reservoir,the special rheology characteristics of heavy oil are always neglected.Therefore,during the process of calculation,there is no concern about the threshold pressure caused by Bingham type rheology property,the results are bigger than that of actual situation and there is a certain gap with the field application.Based on the research of the rheology characteristics of heavy oil and through using the ellipsoidal drainage model,the calculation models of Bingham type fluid for productivity of horizontal well are deduced and the determining methods of threshold pressure are given using Newton-Cotes formulas.Taking a real reservoir as an example,the results between this model and other models are calculated and compared.The results show that productivity calculation result of the model in this paper is smaller than that of other models,which is accordant with the actual oilfield production.