MODELING OF NON-THERMAL RECOVERY OF HEAVY OIL BY CYCLIC SOLVENT INJECTION

循环溶剂注入重油非热采的模拟

• 批准号: RGPIN-2017-04125
• 负责人: Kantzas, Apostolos
• 金额: $ 2.04万
• 依托单位: University of Calgary
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2018
• 资助国家: 加拿大
• 起止时间: 2018-01-01 至 2019-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=655064
• 关键词: MODELING; NON; THERMAL; RECOVERY; HEAVY

There is a considerable push to develop heavy oil using low Green House Gases (GHG, non-steam) processes. This can be achieved using solvent, which may be particularly relevant in the heavy oil fields in Alberta and Saskatchewan that have previously undergone Cold Heavy Oil Production with Sand (CHOPS). Primary production from these reservoirs leads to recovery of 5 – 10% of Original Oil in Place (OOIP) so there are significant volumes of oil still present, and without the ability to inject steam in post-CHOPS fields this makes them excellent candidates to develop non-thermal solvent recovery processes.******Cyclic Solvent Injection (CSI) is a single well process, whereby a vapour phase solvent is injected to pressurize the reservoir. At elevated pressures solvent dissolves into the heavy oil and reduces its viscosity. The well is then placed on production, so well pressure drops and provides a driving force for solvent-diluted oil to flow. Several field pilot studies of this process are already underway. The challenge to CSI is that as the production well pressure drops, solvent comes out of solution and oil viscosity will increase again. Production is a balancing act between achieving flow and keeping gas in solution. Intuition suggests the potential for significant incremental oil production, but what is not defined is whether this process can be commercial. By understanding the physics of CSI (i.e. what controls oil production), and being able to model the process properly, this can help to provide insights into the future viability of this process on a large scale. ******In our past experience in lab-scale core floods, CSI recovery is low after primary production and the pressure decline rate needs to be increased in each successive cycle. In the field, pressure drawdown rates are much slower than in the laboratory, so there are physics present that are not being captured yet in lab studies. The objective of this work is to determine what those physics are, and if there are operational parameters that can be controlled to improve recovery from CSI.******The first part of this program focuses on understanding what mechanisms are important for oil recovery from repeated CSI cycles. Lab tests of CSI generally start after a much higher primary production than what is seen in the field. In addition, core floods generally do not consider the effects of gravity on CSI performance. Finally, PVT tests on oil-solvent systems do not properly represent the non-equilibrium response of solvents leaving solution in oil as a function of pressure and time. Different solvents may also have different non-equilibrium effects, so they may respond differently during depressurization (production) cycles. This program will run experiments to study all of these parameters, and model CSI production capturing the proper recovery mechanisms.

人们大力推动使用低温室气体（GHG，非蒸汽）工艺来开发重油。这可以使用溶剂来实现，这对于先前经历过冷重油的阿尔伯塔省和萨斯喀彻温省的重油田可能尤其重要。这些油藏的初级生产可采收 5-10% 的原始石油地质量 (OOIP)，因此仍然存在大量石油，并且无法在 CHOPS 后注入蒸汽。字段这个使它们成为开发非热溶剂回收工艺的最佳候选者。******循环溶剂注入（CSI）是一种单井工艺，通过注入气相溶剂来对储层加压，溶剂在高压下溶解到储层中。重油并降低其粘度，然后投入生产，因此井压下降并为溶剂稀释的油流动提供驱动力，CSI 面临的挑战是。生产井压力下降，溶剂从溶液中逸出，石油粘度将再次增加。直觉表明，石油产量有显着增加的潜力，但尚未确定的是该过程是否可以商业化。通过了解 CSI（即控制石油生产的因素）的物理原理，并能够正确模拟该过程，这有助于深入了解该过程在未来的大规模可行性。实验室规模岩心洪水、CSI 恢复经验初级生产后压力下降率较低，并且在每个连续循环中需要增加压力下降率。在现场，压力下降率比实验室慢得多，因此存在尚未在实验室研究中捕获的物理现象。这项工作的重点是确定这些物理现象是什么，以及是否存在可以控制的操作参数以提高 CSI 的采收率。 ***** 本计划的第一部分重点是了解哪些机制对于 CSI 的石油采收率很重要CSI 的实验室测试通常在更高的初级生产之后开始。此外，岩心驱替通常不考虑重力对 CSI 性能的影响。最后，油-溶剂系统的 PVT 测试不能正确地表示溶剂在油中留下溶液的非平衡响应。不同的溶剂也可能具有不同的非平衡效应，因此它们在减压（生产）循环期间可能会做出不同的反应，该程序将运行实验来研究所有这些参数，并对 CSI 生产进行建模以捕获适当的回收率。机制。