Dominant mechanisms of multi-phase flow in non-thermal processes for enhanced heavy oil recovery

21世纪，重油开发已开始在加拿大能源中发挥重要作用。加拿大西部蕴藏着大量稠油(粘度高达100,000 mPa.s)；然而，初级生产后原地开采工艺的开发具有挑战性。长期以来，注水一直是常规石油在一次开采后最具成本效益的开采技术。将其推广到稠油油藏遇到了困难：例如，加拿大西部稠油油藏的水驱都表现出很低的波及效率。常规原油注水开发理论已无法预测稠油注水开发的现场动态。因此，对稠油开采过程中多相流机理的基础研究对稠油原地开采技术的发展具有重要意义。在这项拟议的研究中，我将研究稠油油藏注水开发过程中多相流的主要机理，包括水的指进和油的捕获，分散体(水包油和油包水乳状液和泡沫油)在油砂中的流动，油砂中卤水-稠油-天然气流动的相对渗透率，以及利用非热方法提高稠油的水驱。我计划将这项研究扩展到现场应用，将开发的基本理论和模型纳入油藏模拟，用于设计现场注水开发和预测其动态，并提高稠油采收率。我建议进行系统的实验，以深入了解稠油在多孔介质中的复杂驱替过程，并为稠油开发进行数值模拟。除了加拿大以外，大多数稠油油藏正迅速接近其经济产量极限。一次采油和注水采油方法一般最多只能采出最初就位稠油的8%至10%。本文的研究对稠油开发具有重要的现实意义。研究结果也适用于环境工程中土壤和地下水中石油污染物的回收。

Heavy oil development has started to play an important role in Canada's energy in the 21st century. The heavy oil (with viscosities up to 100,000 mPa.s) deposits in western Canada are significant; however, the development of in-situ recovery processes after primary production is challenging. Waterflooding has long been the most cost-effective recovery technique for conventional oil following primary production. Expanding its application to viscous heavy oil reservoirs has encountered difficulties: for example, waterfloods in western Canadian heavy oil reservoirs all exhibit very poor sweep efficiency. Waterflood theory for conventional oil has failed to predict the field performance of heavy oil waterfloods. Therefore, fundamental study of the mechanisms of multiphase flow in heavy oil recovery is essential to the development of in-situ heavy oil processes.      In this proposed research, I will study the dominant mechanisms of multiphase flow during waterflooding in heavy oil reservoirs, including fingering of water and trapping of oil, flow of dispersions (oil-in-water and water-in-oil emulsions and foamy oil) through oil sands, the relative permeabilities for brine-heavy oil-gas flow in oil sands, and enhanced waterflooding for heavy oil by using non-thermal methods. I plan to extend this research to field application by incorporating the developed fundamental theories and models into reservoir simulation for designing field waterflood and predicting their performance, and for enhancing heavy oil recovery. I propose to conduct systematic experiments to gain insight into the complex displacement processes of heavy oil in porous media and perform numerical modelling for heavy oil development.      In Canada, most of the heavy oil reservoirs are fast approaching their economic limits of production. Primary and waterflood methods may generally recover at best 8 to 10% of the heavy oil initially in place. The proposed research is of the most practical significance to heavy oil development. The results of this research are also applicable to the recovery of oil contaminants in soils and groundwater in environmental engineering.