Improved Oil Recovery from Sub-Optimal Reservoirs

该项目旨在帮助加拿大石油工业，目前正在努力从边际质量油藏中经济地生产石油。这些油藏包括对于地表开采来说深度太深但对于常规SAGD作业来说深度不够的沥青矿床、天然裂缝型碳酸盐地层中的稠油矿床、薄稠油地层、因冷采而耗尽但含油饱和度仍然很高的稠油矿床。***建议的工作包括对改进采油过程和改进现有技术的机制进行实验和理论研究，以克服其在从次优质量油藏中采油方面的缺点。为继续开展本项目，拟提出以下研究主题：天然裂缝性油藏的溶剂辅助重力泄油：在天然裂缝性油藏中发现了大量的稠油和超稠油，但成功开发此类油藏仍然具有挑战性。像蒸汽辅助重力泄油和循环蒸汽增产这样的热过程效果不太好，因为储层孔隙度通常很低，单位体积的油必须加热的岩石体积太大。低孔隙度在溶剂型非热工艺中不是问题，但这类工艺通常不能提供足够高的产油量。本项目旨在寻找提高非热过程采收率的方法。* * *二世。用于改进聚合物驱的纳米颗粒：该项目的这一部分旨在开发稠油油藏，这些油藏太薄，无法进行热采。水平井的一次枯竭会留下很大一部分未采出的原油，这在现有技术下是很难开采的。我们建议用纳米颗粒增强聚合物溶液来改进聚合物驱，以研究这类油藏。我们相信，在聚合物溶液中加入具有改性表面特性的纳米颗粒，可以克服目前使用聚合物驱稠油的一些限制。这些限制是高粘度聚合物溶液的低注入性和注入过程中聚合物的剪切降解。从枯竭的油藏中开采稠油：这项工作的重点将是开发一种可以在虫孔中工作的强大的循环溶剂注入工艺。将对添加油溶性发泡剂的新型溶剂混合物进行评估，以找到能够在枯竭油藏中重新激发泡沫驱油的组合。***该项目产生的知识不仅将帮助加拿大石油工业，还将增强对裂缝地层流体流动、纳米颗粒与聚合物相互作用以及循环溶剂过程机制的基本理解

This program aims to help the Canadian oil industry currently struggling to economically produce oil from reservoirs of marginal quality. These include bitumen deposits that are too deep for surface mining but not deep enough for normal SAGD operation, heavy oil deposits in naturally fractured carbonate formations, thin heavy oil formations, heavy oil deposits that have been depleted by cold production but still contain high oil saturation.***The proposed work involves experimental and theoretical examination of mechanisms involved in improved oil recovery processes and modifying the existing technologies to overcome their shortcomings in recovering oil from reservoirs of sub-optimal quality. The following research themes are proposed for the continuation of this program.***i. Solvents Assisted Gravity Drainage in Naturally Fractured Reservoirs: Large volumes of heavy oil and extra heavy oil are found in naturally fractured reservoirs but successful exploitation of such reservoirs remains challenging. Thermal processes like steam assisted gravity drainage and cyclic steam stimulation do not work too well because very often the reservoir porosity is low and the volume of rock that must be heated per unit volume of oil becomes too large. The low porosity is not a problem in solvent based non thermal processes, but such processes generally fail to provide high enough oil production rates. This program aims to find ways of improving the oil recovery rate of non-thermal processes. ***ii. Nanoparticles for Improved Polymer Flooding: This segment of the program is aimed at exploitation of heavy oil reservoirs that are too thin for thermal recovery. Primary depletion with horizontal wells leaves a large fraction of oil unrecovered, which is difficult to produce with currently available technology. The process that we propose to examine for such reservoirs is improved polymer flooding with nanoparticle enhanced polymer solutions. We believe that addition of nanoparticles with modified surface characteristics to polymer solutions can overcome some of the current the limitations in using polymers for heavy oil displacements. These limitations are low injectivity of high viscosity polymer solutions and shear degradation of polymers during injection.***iii. Recovery of Heavy Oil from Reservoirs Depleted with CHOPS: The focus of this work will be to develop a robust cyclic solvent injection process that can work in the presence of wormholes. New solvent mixtures with added oil soluble foaming agents will be evaluated to find combinations that can rekindle the foamy oil drive in the depleted reservoirs.***The knowledge generated by this program will not only help the Canadian oil industry, it will also enhance the basic understanding of fluid flow in fractured formations, interactions of nanoparticles with polymers and mechanisms involved in the cyclic solvent process.**