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

稠油出砂冷采（CHOPS）涉及稠油的连续流动以及砂的流入，以提高采油速率。达到的采收率很低，这使得大量未采收的重油留在CHOPS后的储层中。基于溶剂的提高石油采收率（EOR）工艺，例如循环溶剂注入（CSI）、热水和溶剂的共注入以及溶剂注入与电阻率加热的组合，是在CHOPS后储层中提高产量的最有前途的技术之一。这种EOR工艺的成功应用需要更详细地了解采收机制以及影响储层和操作参数。本研究建议的目的是研究CSI和热水共注入（HW-CSI）以及通过利用电热方法（即电阻率）结合溶剂（ER-CSI）对CHOPS后储层进行原位加热的应用。更具体地说，将研究储层岩石和流体性质的影响，如储层渗透率、虫孔长度和构型以及重油粘度。此外，操作参数的影响，包括溶剂类型，注射压力，段塞尺寸，长度和持续时间的CSI每个注射周期将进行分析。此外，虫洞崩溃的可能性，其影响，和潜在的预防和补救策略CSI和共注入热水和溶剂，以及溶剂注入与电热加热的组合将被彻底调查。建立了一个新的数学模型，考虑流体和岩石性质的动态变化，泡沫油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工艺的整体性能也将进行实验研究。最后，CMG的STARS将用于模拟CSI的实验室规模过程，热水和溶剂的共注入以及溶剂注入和电阻加热的组合。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。从实验研究中获得的结果与数值模拟的结果相结合，将导致参与本研究的研究人员提供一个更准确的数值模拟模型，该模型可以更精确地预测CSI与热水和/或原位加热相结合的性能，同时绘制过程中产生的虫洞的特性。这样的模型允许研究人员和行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.