Enhanced Cyclic Solvent Process and Its Fundamentals for Oil Sands and Heavy Oil Recovery

加拿大西部的油砂和重油矿床非常重要，其开发开始在加拿大能源经济中发挥重要作用。这些矿床中的许多都包含在小于10米产层的储层中，其原位开采具有挑战性。由于重油和沥青的粘度很高或极高，因此必须在其生产的开始或早期阶段应用改进的回收方法。 在这项拟议的研究中，将开发一种在薄储层中原位开采稠油和沥青的工艺--强化循环溶剂工艺，并将研究该工艺所涉及的多孔介质中的多相流动和传质的基本原理。该工艺的基本原理包括溶剂在原油中的分散、溶解气驱、泡沫油的形成和流动以及稠油-溶剂（气）体系的界面现象。该工艺将注气吞吐、注溶剂、泡沫油冷采的主要机理融为一体，克服了传统注气循环工艺的缺点。该组合工艺有效地利用了生产周期中的降粘和泡沫溶液气驱机理。长期目标是通过将开发的基础理论和模型结合到油藏模拟中来将这一过程扩展到现场应用。这些模型将用于设计现场试验和预测提高油砂和重油采收率的性能。 本文的研究成果对天然气法和溶剂法开发油砂和稠油具有重要的现实意义。该研究成果也适用于其他提高采收率的工艺，包括各种稠油热采工艺和注气提高常规采收率工艺。许多其他工程和科学分支也将受益于这项研究，如环境工程中的土壤和地下水修复。

Oil sands and heavy oil deposits in western Canada are significant and their development is beginning to play an important role in the Canadian energy economy. Many of these deposits are contained in reservoirs with less than 10 m pay zone and their in-situ recovery is challenging. Due to the high to extremely high viscosities of heavy oil and bitumen, improved recovery methods must be applied at the beginning or early stage of their production. In this proposed research a process for in-situ heavy oil and bitumen recovery in thin reservoirs - enhanced cyclic solvent process - will be developed and fundamentals of multiphase flow and mass transfer in porous media involved in the process will be studied. The fundamentals of the process include the dispersion of solvent into the oil, solution gas drive, foamy oil formation and flow, and interfacial phenomena of heavy oil-solvent (gas) systems. The new technology combines the major mechanisms of gas huff 'n' puff, solvent injection, and foamy oil flow of cold production into one process to overcome the drawbacks of the traditional cyclic gas injection process. The combined process effectively utilizes the viscosity reduction and foamy solution gas-drive mechanisms in the production cycles. The long term objective is to extend this process to field application by incorporating the developed fundamental theories and models into reservoir simulation. The models will be used to design field tests and predict performance for enhancing oil sands and heavy oil recovery. The proposed research is of greatest practical significance to oil sands and heavy oil development using gas and solvent methods. The results of this research are also applicable to other enhanced oil recovery processes including various thermal methods for heavy oil recovery and gas injection for enhanced conventional oil recovery. Many other engineering and science branches will also benefit from this research, such as soil and groundwater remediation in environmental engineering.