一种压裂水平井不稳定晚期产能预测模型

水平井压裂后流体渗流理论备受国内外学者的重视,现有的水平井压裂后产能预测模型大部分都关注的是压裂后水平井稳态渗流过程产量的计算,而对于整个生产渗流的过程一般都是由不稳定渗流和稳定(拟稳定)渗流两部分组成的,若需要准确的掌握油藏的生产动态,也需要不稳定阶段的产能预测;但是压裂水平井的不稳定渗流模型仅针对不稳定早期阶段,并未涉及压力波传到边界之后不稳定晚期渗流问题。为此,对于一口径向封闭的均质地层可以通过应用复位势理论和压降叠加原理等渗流力学理论,推导出适用于压裂水平井不稳定晚期的流体渗流模型。该模型考虑了裂缝间干扰、裂缝的非对称性、不同裂缝方位角和不同裂缝间距等参数的影响,可更好用于模拟水平井压裂后生产的渗流规律,并选取压裂水平井实例进行产量的计算分析。这对于水平井压裂效果预测和参数优化设计具有指导意义。

A model to predict productivity of fracturing horizontal well at late unstable stage

Nowadays, the percolation theory of fracturing horizontal well is attached great academic importance both domestically and oversea. The current percolation model of fracturing horizontal well at unstable stage is only feasible to the early period of unstable stage, but not to the late period in which the pressure transmission reaches boundary. In order to solve this problem, a series of percolation theories such as complex potential theory, dropout superposition principles and etc. were adopted to derive the percolation model of fracturing horizontal well which is feasible to the late period of unstable stage. This model considered the parameters including interferences between fractures, fracture asymmetry, azimuth of fractures, distances between fractures and etc. to optimize the modeling of the percolation principles of fracturing horizontal well. Furthermore, it is reviewed by example analysis of producing fracturing horizontal well. It has guiding significance in the prediction of fracturing effect and parameter optimization.