基于变权模糊综合评判的ICD类型优选研究

Selection of inflow control devices based on dynamic weight fuzzy evaluation

长水平井易过早见水/气,一旦油井发生水/气锥,将在锥进处形成快速流动通道并抑制非锥进处的流动。在完井段上安装流入控制装置(ICD)可以有效延缓见水/气时间,提高采收率。由于使用ICD的油井通常能生产5~20年,装置的稳定性和ICD类型的选择对油井的开发十分重要。但是当前ICD类型的选择主要依赖于对ICD性能的定性认识,缺乏科学的理论依据。本文基于数值模拟软件,选取不同结构的ICD装置,研究了装置的流体参数敏感性、抗冲蚀和防堵塞性。基于数值模拟结果,结合模糊综合评判方法,引入变权理论,提出了一种科学的ICD优选方法。研究结果表明:ICD类型优选的主要考虑因素是黏度敏感性、流量大小和过流面积。通过比较ICD在不同黏度和流量下的优属度,构建了ICD优选图版。利用该图版,只要确定了储层条件,即可快速得到最优ICD类型,为油井的ICD选型提供科学的指导。

Early water or gas breakthrough is usually encountered due to an imbalanced production profile. Once water or gas coning occurs in horizontal wells, the flow rate in the coning zone will be high because of the low viscosity of water and gas and the flow in the other zone will be hindered. Inflow control devices（ICD） can enhance the reservoir sweep efficiency and oil recovery. Hence, ICD stability and selection is crucial for well production. However, current ICD selection for a specific reservoir mainly depends on the qualitative awareness of both the reservoir conditions and the ICD performance. Based on CFD simulation, this paper proposed an ICD selection method, which considers the fluid property sensitivity, plugging and erosion resistances and combines fuzzy evaluation and dynamic weight theory. The results show that ICD selection mainly depends on the viscosity sensitivity, flow rate, and cross section area of the ICDs. An ICD selection diagram is built with the comparison of optimal membership degrees of three designs at varying reservoir conditions. The optimal ICD can be selected immediately with the help of the ICD selection diagram once reservoir conditions are determined.