基于多目标遗传算法的水平井裂缝参数优化

Optimization of fracture parameters of fractured horizontal well based on multi-objective genetic algorithm

为了改善低渗透、超低渗透油藏油井自然产能低的状况,需对压裂水平井采油、直井注水的采油方式进行参数优化研究。以国内某区块低渗透油藏开发实例为基础,以七点法直井-水平井混合井网压裂水平井为研究对象,将多目标优化遗传算法NSGA-Ⅱ引入到水平井压裂裂缝参数优化设计中,形成了一种新的优化方法,并编制了相应的软件。该方法将水平井采出程度和含水率作为目标函数,以寻求Pareto最优解集为目的,利用软件对低渗透油藏七点法直井-水平井混合井网压裂水平井裂缝参数进行了优化设计。研究证明,该优化方法适合推广应用。

The production method of using fractured horizontal well as producer and vertical well as injector has been optimized to improve productivity for low permeability and ultra low permeability reservoirs. For a seven-spot pattern with combination of vertical and fractured horizontal wells for a domestic low permeability reservoir,the multi-objective genetic algorithm NSGA-Ⅱ is introduced in optimization of fracture parameters of horizontal well,thereby formed a new optimization method and formulated corresponding software. The algorithm takes recovery rate and water cut as objective functions,the purpose is to seek for the optimal Pareto solutions,and the fracture parameters of horizontal well in such a pattern and reservoir are optimized by the software. This optimization method suits to be popularized.