Cyclic Hot Solvent Injection (CHSI) Process for Enhanced Heavy Oil Recovery in Thin Reservoirs

我的研究计划的长期目标之一是开发有效和高效的技术，以环境可持续的方式开发加拿大西部的重油资源。加拿大西部拥有世界第二大石油资源。90%以上是重油和沥青。其中，约320亿的重油储存在劳埃德明斯特地区。劳埃德明斯特稠油油藏具有油层薄(平均厚度3~5m)、含油饱和度高(平均85%)、高渗透率(平均2D)、高粘度(1000~1.2万cp)的特点。带砂冷采(CHOPS)是该地区的主要采油方式。然而，只有10%-15%的石油可以用排骨生产。尽管劳埃德明斯特稠油油藏迫切需要提高采收率。目前的稠油提高采收率方法在工业上都不可行。*本研究计划提出一种新的混合工艺--循环热溶剂注入(CHSi)工艺，并将进行基础和应用研究。新发明的CHSi工艺是一种基于单井的工艺，其中使用接近露点的加热溶剂作为注入液。在CHSi工艺的每个周期中，类似于CSI工艺，有三个阶段：注入溶剂、浸泡和生产。CHSi工艺使用的溶剂是丙烷或丁烷。注入的溶剂可以加热到50-100摄氏度，这取决于使用的是哪种溶剂。井筒应该隔热，以防止通过井筒的热损失和井筒中的溶剂凝结。在注入和浸泡期间，储集层中发生了热量和质量的传递。溶剂携带的潜热和显热转移到油藏/烃类体系，溶剂溶解到稠油中。由于油层温度的升高和溶解的溶剂，原油的粘度会降低。在采油期，油藏的压力和温度都会逐渐降低。泡沫油流、溶解气驱和重力效应是驱油的主要机制。CHSi工艺是一种新工艺，其他研究人员尚未对其进行研究。在过去的两年里，通过我的NSERC发现发展基金，已经对CHSi工艺进行了初步评估，并取得了可喜的结果。专利申请正在进行中，以保护这项发明的知识产权。提出的研究计划是为了评价CHSi工艺的性能，更好地了解不同压力和温度影响下CHSi工艺的基本物理，并测量在现场尺度上评价该工艺性能所需的基础数据。

One of the long-term goals of my research program is to develop effective and efficient techniques to unlock Western Canada's heavy oil resources in an environmentally sustainable way. Western Canada has the second largest oil resource in the world. Over 90% is heavy oil and bitumen. Among them, about 32 billion of heavy oil is deposited in Lloydminster area. The heavy oil reservoirs in Lloydminster are featured with thin pay-zone (in average 3-5 m thick), high oil saturation (average 85%), high permeability (average 2D), and high viscosity (1000 12,000 cp). Cold Heavy Oil Production with Sand (CHOPS) is the main recovery method in this area. However, only 10-15% of oil can be produced with CHOPS. Even though enhanced oil recovery method is strongly needed for Lloydminster heavy oil reservoir. None of current enhanced heavy oil recovery method is commercially viable. ******This research program is proposing a new hybrid process, Cyclic Hot Solvent Injection (CHSI) process and both fundamental and application studies will be conducted. The new invented CHSI process is a single well based process where heated solvent in its near dew point is employed as injection fluid. In each cyclic of the CHSI process, similar to CSI process there have three periods: solvent injection, soaking and production. The solvent used for CHSI process is propane or butane. The injected solvent can be heated to 50-100 C, depending on which solvent is used. The wellbore should be insulated in order to prevent heat loss through the well bore and condensation of solvent in the wellbore. During the injection and soaking periods, both heat and mass transfers occur in the reservoir. The latent heat and sensible heat carried by the solvent will be transferred to the reservoir/hydrocarbon system and solvent will dissolve into the heavy oil. The oil viscosity will be reduced due to the increased reservoir temperature and the dissolved solvent. In the oil production period, both pressure and temperature of the reservoir will be decreased gradually. Foamy oil flow, solution gas drive and gravity effects are the main driving mechanisms of the oil production. The CHSI process is a new process and has never been investigated by other researchers yet. During the past two years, through my NSERC Discovery Development Grant preliminary assessment of CHSI process has been conducted and promising results have been obtained. Patent application is in the process to protect the Intellectual Property of this invention. The proposed research program is to evaluate the performance of CHSI process, better understand the fundamental physics of CHSI process under different pressure and temperature effects and measure fundamental data which needed to evaluate the performance of this process in field scale.*****