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。低矿化度水驱是提高采收率的一个有希望的趋势。低矿化度水驱是近年来研究的热点。最近的实验室和现场工作表明，低矿化度注水可以显著提高轻质油油藏的采收率。虽然提出了许多恢复机制，但仍存在许多问题和不确定性。本课题主要研究盐度对采收率的影响机制。这需要开展基础研究工作，从加拿大中/稠油油藏的角度研究这一过程（聚合物/盐水）的影响，可能包括对排水和吸胀毛管压力、岩石润湿性变化和有效渗透率的影响。在孔隙水平上改变矿化度的恢复机制也亟待进一步研究；在这种情况下，我们的提案将解决盐度对水与岩石表面之间表面张力的影响，并研究不同盐度的水与不同岩石表面之间的附着力。进一步研究了水矿化度对聚合物流变性的影响。最近报道了另一个与水本身有关的有希望的趋势。对于含盐量较高的卤水，采收率也有较大的变化。为了实现这些目标，拟议的项目将调查：注入水盐度（离子浓度和阳离子类型：钠、钙和钾）对石油采收率（最佳盐度）的影响；注入水盐度温度；硬石膏和白垩的溶解；pH值;矿物表面润湿性；粘土含量;表面电荷的电位离子；注入水矿化度对聚合物流变性的影响注入水矿化度对聚合物稳定性的影响；注入水矿化度对聚合物迁移率的影响；阴离子类型;酸值;不同的流体注入策略（同时/交替注入）和聚合物段塞尺寸。

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.