Experimental and Numerical Simulation Studies of Cyclic Solvent Injection (CSI) Coupled with Hot-Water Injection and Electro-Thermal Heating in Post CHOPS Reservoirs

含砂冷稠油开采（chop）涉及稠油的连续流动和砂的流入，以提高石油产量。目前的采收率很低，在chop后油藏中留下了大量未采出的稠油。基于溶剂的提高采收率（EOR）工艺，如循环溶剂注入（CSI）、热水和溶剂共注入以及溶剂注入与电阻率加热相结合，是后chop油藏最有前途的增产技术。成功应用此类EOR工艺需要更详细地了解采收率机制以及对油藏和作业参数的影响。本课题的研究目的是探讨利用电热法（即电阻率法）结合溶剂法（ER-CSI法）进行现场加热和热水共注（HW-CSI法）在后chop油藏中的应用。更具体地说，将研究储层岩石和流体性质（如储层渗透率、虫孔长度和配置以及稠油粘度）的影响。此外，还将分析溶剂类型、注入压力、段塞尺寸、每个注入周期的长度和持续时间等操作参数对CSI的影响。在此基础上，深入探讨了蚓孔塌陷的可能性、影响、CSI、热水与溶剂共注以及溶剂注入与电热加热相结合的预防和修复策略。将建立一个新的数学模型，以考虑流体和岩石性质的动态变化、泡沫油的流动以及虫孔的生长。沥青质沉淀对泡沫油行为的影响以及该过程的整体性能也将进行实验研究。最后，CMG的STARS将用于模拟CSI，热水和溶剂共注入以及溶剂注入和电阻加热相结合的实验室规模过程。模拟模型将与实验结果进行历史匹配，并用于评估其他参数（如各种井配置和渗透率各向异性）的影响。将实验研究结果与数值模拟结果相结合，将使参与本研究的研究人员能够提供更精确的数值模拟模型，该模型可以更精确地预测后chop油藏中CSI与热水和/或原位加热相结合的性能，同时绘制出在此过程中产生的虫孔的属性。这样的模型允许研究人员和工业工程师优化操作条件，以最大限度地提高CSI的性能。

Cold heavy oil production with sand (CHOPS) involves the continuous flow of heavy oil together with an influx of sand to enhance oil production rates. The achieved recovery rates are low which leaves a significant amount of unrecovered heavy oil in post CHOPS reservoirs. Solvent-based enhanced oil recovery (EOR) processes such as cyclic solvent injection (CSI), co-injection of hot water and solvent as well as the combination of solvent injection with electro-resistivity heating are among the most promising techniques to enhance production in post CHOPS reservoirs. The successful application of such EOR processes requires a more detailed knowledge of recovery mechanisms and affecting reservoir and operational parameters. It is the objective of this research proposal to investigate the application of CSI and co-injection of hot water (HW-CSI) as well as in-situ heating through the utilization of electro-thermal methods (i.e. electro-resistivity) combined with solvents (ER-CSI) for post CHOPS reservoirs. More specifically, the effects of reservoir rocks and fluid properties such as reservoir permeability, wormhole length and configuration, and heavy oil viscosity will be studied. In addition effects of operating parameters including solvent type, injection pressure, slug size, length and duration of each injection cycle for CSI will be analyzed. Furthermore, the possibility of wormhole collapse, its effects, and potential prevention and remediation strategies for CSI and co-injection of hot water and solvent as well as combination of solvent injection with electro-thermal heating will be thoroughly investigated. A novel mathematical model will be developed to consider the dynamic changes in fluid and rock properties, foamy oil flow as well as the growth of wormholes. The effects of asphaltene precipitation on foamy oil behavior as well the overall performance of the processes will be also experimentally studied. Finally, CMG’s STARS will be used to simulate lab-scale processes for CSI, co-injection of hot water and solvent and combination of solvent injection and electro-resistance heating. The simulation model will be history matched with the experimental results and used to evaluate the effects of other parameters such as various well configurations and permeability anisotropy. A combination of the results obtained from experimental studies with those from numerical simulation will lead the researchers involved in this study to provide a more accurate numerical simulation model that can predict the performance of the CSI combined with hot-water and/or in-situ heating in post CHOPS reservoirs more precisely and while mapping the properties of the wormholes generated during the process. Such a model allows the researchers, and industry engineers to optimize the operating conditions to maximize the performance of CSI.