Investigating the Effect of Polymer/Low Saline Water Injection on the Recovery of Medium/Heavy Oil Reservoirs

在许多油田进行了数千个成功的注水工程。这是一项经过验证的技术，即使在低采收率水平下也具有可靠、低风险和经济效益。自20世纪90年代以来，这项技术的大部分知识空白已被填补。然而，如何优化其性能，扩大其应用范围，特别是中稠油油藏的应用，是目前尚未得到足够重视的重要研究领域。本研究计划着眼于加拿大中/稠油碳酸盐岩油藏“聚合物/低盐注水”碳氢化合物工艺的应用和采收率（低盐水与聚合物驱相结合是非常有趣的）。这项研究的好处是，它可以显著提高原油采收率，特别是中/稠油采收率，同时减少系统设施的过量产水。这个项目专门涉及水库工程。

Thousands of successful water flood projects are operated in many oil fields. It is a proven technology that is reliable, low-risk, and economically favorable even at low recovery levels. Most of the knowledge gaps with this technology since the 1990's have been filled. However, optimizing its performance and extending its application, specifically to medium and heavy oil reservoirs, are important research areas which have not received adequate attention. This research proposal looks at the application and recovery of the hydrocarbons process “Polymer/Low Saline Water Injection” for Canadian medium/heavy oil carbonate reservoirs (low salinity water in combination with polymer flooding is of great interest). The benefit of this research is that it could significantly improve oil recovery, especially medium/heavy oil recovery, while reducing the excessive water production into the system facilities. This project relates specifically to reservoir engineering. One promising trend for increasing oil recovery is low salinity waterflooding. Low salinity in waterfloods has become an active research area in recent years. Recent lab and fieldwork have illustrated that low salinity water injection for light oil reservoirs can significantly improve oil recovery. While many recovery mechanisms are proposed, many questions and uncertainties still remain. This research proposal focuses on addressing the recovery mechanisms caused by water salinity. This will require conducting fundamental research work to study the effects of this process (polymer/saline water) from the standpoint of Canadian medium/heavy oil reservoirs, and may include the impact on drainage and imbibition capillary pressures, rock wettability alternation, and effective permeability. There is also urgency to have a better understanding of the recovery mechanisms of changing the salinity at pore scale level; in this case, our proposal will address the salinity effect on surface tension between water and rock surface and study of the adhesion forces between different salinity waters and different rock surfaces. Furthermore, the effect of water salinity on polymers rheology will be studied. Another promising trend related to the water itself has recently been reported. Large variation in oil recovery has also been observed for brine of comparatively high salinity. To achieve these objectives, the proposed project will investigate the effect of: injected water salinity (ion concentration and cation type: sodium, calcium and potassium) on oil recovery (optimum salinity); injected water salinity's temperature; dissolution of anhydrite and chalk; pH; mineral surface on wettability; clay content; potential ions on surface charge; injected water salinity on polymer rheology; injected water salinity on polymer stability; injected water salinity on polymer mobility; anion type; acid number; different fluid injection strategies (simultaneous/alternate injection) and polymer slug size.