University of Alberta, Canada.
University of Alberta, Canada.
Adv Colloid Interface Sci. 2015 Jun;220:54-77. doi: 10.1016/j.cis.2015.02.006. Epub 2015 Mar 5.
Changing the wetting state of materials is a growing field of research in many areas of engineering and science. In the oil industry, the term wettability alteration usually refers to the process of making the reservoir rock more water-wet. This is of particular importance in naturally hydrophobic carbonates, fractured formations, and heavy-oil systems. This shift in wettability enhances oil recovery in oil-wet and weakly water-wet reservoirs and eventually increases the ultimate oil recovery. For wettability alteration, two methods have been traditionally used: Thermal and chemical. Although many attempts have been made on reviewing the advancement of research in certain aspects of wettability, a comprehensive review of these techniques, especially in terms of the classification of the chemicals used, has been ignored. In this paper, we begin with this review and provide the past experience of wettability alteration in sandstone and carbonate reservoirs. More than 100 papers were reviewed extensively with an in-depth analysis of different methods suggested in literature. The areas of controversy and contradicted observations are discussed. The limitations and the applicability of each method were analyzed. Concerns on up-scaling laboratory findings to field scale are also addressed. The most promising potential methods are identified and their critical conditions highlighted. At the end, a selection of reviewed methods is validated experimentally for one of the most challenging cases: Extra heavy-oil and bitumen recovery from fractured-strongly-oil-wet carbonates. Berea sandstone (aged to be oil-wet) and Indiana limestone samples were saturated with heavy oil (3600cp). Next, the process was initiated by soaking the cores into solvent (heptane or diluent oil) and the oil recovery was estimated using refractive index measurements. Note that solvent was selected to dilute the oil and recover a considerable amount of oil as any chemical or thermal methods yielded inefficiently low recoveries. After the solvent phase, the samples were exposed to wettability alteration through selected chemicals at different temperature conditions through spontaneous imbibition tests to recover more oil and retrieve the solvent diffuse into the sample back. The most promising wettability alteration agents for each type of rock were marked and optimal application conditions (temperatures, injection sequence) were identified. Selected wettability alteration chemicals were finally tested on the bitumen (5-9° API-1,600,000cp) containing Grosmont carbonate sample from Alberta, Canada. It is hoped that this review fills in the gap in the area of wettability alteration processes by summarizing, critically analyzing, and testing the methods suggested in the literature.
改变材料的润湿状态是工程和科学许多领域中日益发展的研究领域。在石油工业中，润湿性改变这个术语通常是指使储层岩石更亲水的过程。在天然疏水性碳酸盐岩、裂缝地层和重油系统中，这一润湿状态的转变尤其重要。这种润湿性的转变提高了油湿和弱水湿储层的采油率，最终提高了最终采油量。对于润湿性改变，传统上使用了两种方法：热法和化学法。尽管在某些方面对润湿性研究进展进行了许多尝试，但对这些技术的全面综述，特别是对所用化学品的分类，却被忽略了。本文从这一综述开始，并提供了砂岩和碳酸盐岩储层润湿性改变的过去经验。对 100 多篇论文进行了广泛的回顾，并对文献中提出的不同方法进行了深入分析。讨论了有争议和相互矛盾的观测结果的领域。分析了每种方法的局限性和适用性。还讨论了将实验室发现推广到现场规模的问题。确定了最有前途的潜在方法，并强调了其关键条件。最后，对其中一个最具挑战性的案例——从裂缝强油润湿碳酸盐岩中回收稠油和沥青，选择了经过审查的方法进行了实验验证。Berea 砂岩（老化为油湿）和印第安纳石灰岩样品用重质油（3600cp）饱和。接下来，通过将岩心浸泡在溶剂（庚烷或稀释油）中启动该过程，并通过折射率测量估计油的回收量。请注意，选择溶剂是为了稀释油并回收相当数量的油，因为任何化学或热方法的回收率都非常低。在溶剂相之后，通过在不同温度条件下通过自发吸入试验用选定的化学品进行润湿性改变，以回收更多的油并将扩散到样品中的溶剂回收回来。为每种类型的岩石标记了最有前途的润湿性改变剂，并确定了最佳应用条件（温度、注入顺序）。最后，在含有阿尔伯塔省 Grosmont 碳酸盐岩的沥青（API-1,600,000cp）的加拿大加拿大沥青样品上测试了选定的润湿性改变化学剂。希望本综述通过总结、批判性分析和测试文献中提出的方法，填补润湿性改变过程领域的空白。
