Simulation Study of Enhanced Oil Recovery by Alkaline Flooding in a Mature Oil Field
全球的石油储量被勘探和商业化以获取其中的化石燃料。随着多年的生产，这些储量趋于枯竭，这促使人们要么发现新的储量，要么提出更有效的提取方法。增强石油回收（EOR）旨在提取通过初级和次级回收机制无法回收的残余油。碱性水驱是成本最低且经济的EOR方法之一，因为它容易获得且不复杂。本研究的目标是评估改变碱性浓度、流速和流期的效果，通过构建使用CMG计算机建模软件的模拟模型，并进行敏感性分析。结果表明，井型和射孔层对产量有显著影响，除了变化的碱性参数外，还能增加产量。
CMG软件的应用情况
在本研究中，CMG STARS软件被用来构建油田的数值模型，并进行模拟以评估碱性水驱的油藏工程效果。模型采用了倒置五点注水模式（五个生产井和一个注入井），总共有293个网格块。通过模拟，研究了改变碱性参数对油藏回收率的影响，包括碱性浓度、流速和流期。模拟分为三个阶段：初级水驱、次级水驱和三级EOR（碱性水驱）。通过比较这三种油藏回收方法，得出了最高的油回收配置。
Abstract
Oil reserves that are available all over the world are explored and commercialised to obtain the fossil fuels it contains. Over the years, due to production, these reserves tend to deplete which leads to a drive to either discover new reserves or come up with much effective method to extract the fossil fuels. Enhanced Oil Recovery (EOR) is carried out to extract the remaining oil that is trapped in it as residual oil and unable to be recovered through primary and secondary recovery mechanism. Alkaline flooding is not only one of the cheapest EOR methods but also one of the most economical method to recover oil as it is easily acquired and is not a very complex substance. The basic concept of alkaline flooding is to inject the alkaline at a certain concentration and rate into the reservoir and this in return reacts with the oil acid to produce soap which is an in-situ surfactant. Due to this reaction, the generated surfactant reduces the interfacial tension (IFT) between the oil and the reservoir rocks which leads to the increase in sweep efficiency. In this study, the objective is to evaluate the effect of altering the alkaline concentration, flow rate and flow period by constructing a simulation model using the reservoir fluid and rock date in Computer Modelling Software (CMG). Sensitivity analysis was performed and the outcomes demonstrated that well pattern and perforation layer has a significant influence on production besides the varying alkaline parameters which also increases production.
Keywords
Enhanced oil recovery; EOR, tertiary recovery, alkaline flooding, interfacial tension; IFT, simulation, CMG, STARS
