Nanoparticle-assisted enhanced oil recovery (Nano-EOR) in unconventional oil reservoirs

加拿大拥有巨大的非常规石油资源，而世界范围内的常规石油储量正在枯竭。例如，加拿大西部和邻近的美国各州的巴肯地层大约有271503亿桶轻质石油。在这种致密地层中，一次采油的采收率低至13%。另一方面，加拿大的重油储量估计为550亿桶。典型的稠油出砂冷采（CHOPS）采收率可达515%，因此，加拿大CHOPS后油藏中剩余8595%的稠油有待开采。在许多情况下，传统的提高石油采收率（EOR）方法不能有效且经济地开采这些非常规油藏。 在过去的十年中，一些有限的跨学科研究表明，纳米技术可能为EOR目的带来很大的希望。特别是，与传统EOR工艺中常用的水、溶剂、化学品和蒸汽相比，尺寸为1100 nm的纳米颗粒（NP）显示出作为新EOR剂的一些显著特性。因此，NP辅助提高采收率（简称纳米提高采收率）为非常规油藏的开发提供了一种有效的、新型的提高采收率技术。目前，纳米EOR还处于起步阶段。纳米提高采收率技术能否成功应用于油田尚属未知数。 拟议的NSERC DG研究计划的主要目标是为非常规油藏提供急需的新型纳米EOR技术的创新和基础研究。一些现有的或新的实验方法，分析技术，数学模型和数值模拟将被应用于追求以下三个主要研究目标。首先，将研究和开发一些稳定的和合适的纳米流体（NF）用于纳米EOR。其次，NP保留在多孔介质中将被测量和建模。第三，几个有前途的水和/或二氧化碳为基础的纳米EOR过程将进行实验测试和数值模拟，以确定最好的纳米EOR过程中巴肯形成和加拿大后CHOPS水库。 这个新的DG研究计划将通过研究EOR机制以及新型Nano-EOR过程中NP，油藏流体和地层之间的复杂相互作用来产生新的知识。它将为未来的纳米EOR项目提供及时，直接和强有力的技术支持。加拿大石油工业将通过实施一些有效的纳米EOR项目和从几个巨大的富油地层中回收剩余的轻质和重油而受益匪浅。此外，Nano-EOR还将有助于减少轻质油生产中的水和溶剂用量以及重油生产中的温室气体排放。从长远来看，加拿大将继续开发新颖先进的EOR技术，加拿大人也将继续保护丰富的淡水和清洁的空气。

Canada has tremendous unconventional oil resources, while the conventional oil reserves are being depleted worldwide. For example, the Bakken formation in Western Canada and the adjacent US states has approximately 271503 billion barrels of light oil-in-place. The oil recovery factors of the primary production in such a tight formation are as low as 13%. On the other hand, the Canadian heavy oil reserves are estimated to be 55 billion barrels. A typical cold heavy oil production with sand (CHOPS) can recover 515% and thus 8595% heavy oil is left in the Canadian post-CHOPS reservoirs to be recovered. In many cases, the traditional enhanced oil recovery (EOR) processes cannot effectively and economically exploit these unconventional oil reservoirs. In the past decade, some limited cross-disciplinary studies have indicated that nanotechnology may hold great promise for EOR purposes. In particular, nanoparticles (NPs) with sizes of 1100 nm show some remarkable characteristics as new EOR agents, in comparison with water, solvents, chemicals and steam that are commonly used in the traditional EOR processes. Thus NP-assisted EOR, which is abbreviated as Nano-EOR, may offer an effective and novel EOR technology to exploit the unconventional oil reservoirs. At present, Nano-EOR is in its infancy. It is still unknown whether Nano-EOR technology can be successfully applied in the oilfields. The primary objective of the proposed NSERC DG research program is to deliver much-needed innovative and fundamental studies of novel Nano-EOR technology for the unconventional oil reservoirs. Some existing or new experimental methods, analytical techniques, mathematical models and numerical simulations will be applied to pursue the following three major research objectives. First, some stable and suitable nanofluids (NFs) will be studied and developed for Nano-EOR. Second, NP retention in a porous medium will be measured and modeled. Third, several promising water- and/or CO2-based Nano-EOR processes will be experimentally tested and numerically simulated to identify the best respective Nano-EOR processes in the Bakken formation and Canadian post-CHOPS reservoirs. This new DG research program will generate new knowledge by studying the EOR mechanisms and complex interactions among NPs, reservoir fluids and formations in the novel Nano-EOR processes. It will provide timely, direct and strong technical support for future Nano-EOR projects. The Canadian petroleum industry will benefit considerably by conducting some efficient Nano-EOR projects and recovering the remaining light and heavy oils from several vast oil-rich formations. Furthermore, Nano-EOR will also help to reduce water and solvent usages in the light oil production and greenhouse gas emissions in the heavy oil production. In the long run, Canada will continue to develop novel and advanced EOR technologies and Canadians will also continue to conserve abundant fresh water and clean air.