蛇曲井稳态产能计算模型

蛇曲井是一种新的复杂结构井，其生产井段起伏较大，不能直接用常规水平井产能公式计算其产能。以1口蛇曲井在无界地层中生产时引起的势分布为基础，根据镜像反映和势叠加原理，建立了底水油藏、气顶底水油藏及边水油藏中1口蛇曲井生产时的势分布和压力分布方程。考虑井筒流动和地层渗流的耦合作用，建立了蛇曲井的稳态产能计算模型，给出了模型的求解方法。实例计算表明：当井的水平段起伏较大时，不能将其处理为水平井，而应根据蛇曲井产能计算模型计算其产能，否则将导致产能预测出现较大偏差。

Steady state productivity model of snaky wells

Snaky well is a new type of complex well.The wellbore pressure drop of snaky well can't be neglected for its producing interval has large fluctuation,and the conventional productivity calculation methods for horizontal wells could not be applied directly for snaky wells.It is necessary to set up a model for calculating steady state productivity of snaky wells.On the basis of a snaky well's distribution of potential produced in an infinite reservoir,this paper uses the mirror image and the principle of superposition to obtain the velocity potential and pressure distribution for bottom water reservoirs with and without gas cap,and edge water reservoir.Coupling wellbore flow with fluid flow in the formation,a steady state productivity model for the snaky well is developed and solved.Example calculation shows that the steady state productivity model of snaky well should be used in calculating the productivity of a horizontal well with large fluctuation;otherwise,big errors would be produced.