Improving SAGD by applying emulsion based reservoir conformance control method

由于油砂储层的非均质性，该研究直接解决了蒸汽辅助重力排水(SAGD)工艺中的一致性问题(即蒸汽室发展不均匀，因此部分失去了可用于沥青回收的储油层)。为了提高非均质油砂油藏的热效率，从而提高SAGD作业的经济性，需要对低渗透层进行地质机械扩张，使其对蒸汽具有渗透性。在低流度层扩张过程中，暂时封堵高渗透层是至关重要的。该项目将开发一种用于SAGD符合性控制的乳状液封堵技术。在这个项目中，将在高达典型蒸汽温度(~200摄氏度)的温度下产生热稳定的水包沥青乳液。实现高渗透区渗透率降低99.5%以上，促进SAGD蒸汽室均匀生长。该项目的目标是利用碱、表面活性剂和纳米颗粒之间的协同作用，在盐水中乳化沥青，在中等界面张力条件下生成稳定的乳状液。将通过进行各种物理模型试验来评估和优化乳剂在SAGD合规性控制中的性能。将建立用于乳状液封堵降低渗透率和控制顺应性的数学和数值模型。Brion Energy和BitCan已同意支持本文提出的基于乳液的符合性管理研究，并在Brion的储油层测试在该项目中开发的乳液系统。油藏模拟将用于SAGD符合性控制作业的现场测试设计，并将通过分析现场测试结果进行验证。该项目的研究成果将适用于加拿大其他油砂油藏的SAGD符合性控制膨胀启动和投产后的SAGD符合性改进，并可应用于全球相关工艺。实施拟议的油砂回收新技术的预期好处是显著节省能源、减少用水量和减少温室气体排放。

The proposed research directly addresses the conformance problem (i.e., uneven steam chamber development and therefore partial loss of available reservoir for bitumen recovery) in the Steam-Assisted Gravity Drainage (SAGD) process due to the heterogeneity of oil sands reservoirs. To improve the thermal efficiency and therefore the economics of SAGD operations in heterogeneous oil sands reservoirs, the low permeability zones need to be geo-mechanically dilated to make them permeable to steam. It is crucial to temporarily block the high-permeability zones during dilation of the low mobility zones. This project will develop an emulsion blocking technique for SAGD conformance control. In this project, thermally stable bitumen-in-water emulsions will be generated at temperatures up to typical steam temperature (~200oC). More than a 99.5% permeability reduction in high permeability zones will be realized, and a uniform growth of the SAGD steam chamber will be promoted. This project will target to generate stable emulsions under moderate interfacial tension conditions by utilizing the synergy between alkalis, surfactants, and nanoparticles in the emulsification of bitumen in brine. The performance of emulsions in SAGD conformance control will be evaluated and optimized by conducting various physical model tests. Mathematical and numerical models for permeability reduction and conformance control by emulsion blocking will be developed. Brion Energy and BitCan have agreed to support the herein proposed emulsion-based conformance management research, and to test the emulsion systems developed in this project in Brion's reservoirs. Reservoir simulation will be performed for field test design of SAGD conformance control operations and will be validated by analyzing field test results. The research outcomes of this project will be applicable to SAGD conformance controlled dilation start-up and SAGD conformance improvement after start-up operations in other oil sands reservoirs in Canada and to related processes globally. The anticipated benefits of implementing the proposed new technique for oil sands recovery are significant energy savings, reduced water consumption, and reduced greenhouse gas emissions.