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.

考虑到使用低温室内气体（GHG，非步骤）工艺开发重油的考虑。这可以使用溶剂来实现，这可能在艾伯塔省和萨斯喀彻温省的重油田中特别相关，这些油田以前曾用沙子（土壤）经历过冷的重油生产。这些储层中的一级生产可导致5 - 10％的原始油（OOIP）恢复（OOIP），因此仍然存在大量的油，并且没有能力在储物柜后领域注入蒸汽的能力，这使它们成为一种非常出色的候选者，使它们可以开发非热的溶解度流程。水库。在高高的压力下，溶剂溶解在重油中并降低其粘度。然后将井放在生产上，因此压力下降，并为解决的油流动提供了驱动力。该过程的几项现场试验研究已经在进行中。 CSI面临的挑战在于，随着产量的压力下降，溶剂溶液会出现，石油粘度将再次增加。生产是实现流量和保持溶液中的气体之间的平衡行为。直觉表明有大量渐进石油生产的潜力，但未定义的是该过程是否可以是商业化。通过了解CSI的物理学（即控制石油生产），并能够正确建模过程，这可以有助于洞悉大规模的该过程的未来可行性。 *****在我们过去在实验室核心地板上的经验中，CSI恢复量很低，在每个成功周期中，需要提高压力下降速度。在现场，压力下降速率比实验室慢得多，因此存在的物理学尚未在实验室研究中捕获。这项工作的目的是确定这些物理学是什么，以及是否有可以控制的操作参数可以改善CSI的恢复。******该程序的第一部分重点是了解哪些机制对于重复的CSI周期中的石油回收很重要。 CSI的实验室测试通常是在初级产生要比现场高得多的基础生产后开始的。此外，核心地板通常不考虑重力对CSI性能的影响。最后，对石油溶剂系统的PVT测试不能正确地表示溶液的非平衡响应，这是压力和时间的函数。不同的溶液也可能具有不同的非平衡效应，因此在降压（生产）周期期间它们的反应可能有所不同。该程序将运行实验以研究所有这些参数，并模拟CSI生产以捕获适当的恢复机制。