Investigating Three-Phase Flow of Steam-Water-Oil in Porous Media for Maximizing SAGD Potential: A New Measurement Technique

该研究计划为多孔介质中三相流的基础研究开发了一种新的实验室技术和程序。测量的数据将用于预测和优化加拿大重油和沥青资源的石油生产的原位热采方法。在阿尔伯塔和萨斯喀彻温省存在超过3000亿立方米的粘性沥青。只有三分之一的巨大资源足以满足整个北美100多年的碳氢化合物需求。然而，只有20%的资源可以通过地表采矿获得。其余80%需要现场方法，如蒸汽辅助重力泄油（SAGD）。SAGD已被证明是加拿大最成功的稠油和沥青现场开采方法。在SAGD中，蒸汽、蒸汽凝析油和油同时流过岩石孔隙空间。数学建模和优化这些过程需要在实验室中仔细测量每个相的流导（相对渗透率）和残余饱和度。然而，蒸汽、油和水的相对渗透率曲线的实验室确定由于相饱和度的困难（即，体积分数）测量。主要的挑战是区分具有相似密度的水相和油相。本研究的A阶段开发了一种新的非破坏性方法，用于测量同时流过限制在岩心保持器内的多孔介质的油、水和蒸汽的饱和度。在该方法中，通过基于X射线的技术测量总的油和水饱和度（So + Sw），并且通过基于电容（由介电常数描述）的技术测量水饱和度（Sw）。水的介电常数比油的介电常数高几倍，这允许计算每个相的分数。在时间和空间上测量的三相饱和度将被解释和建模，以获得饱和度空间中每个点的三相相对渗透率。研究的B阶段开发数学技术，使用测量数据来评估、预测和优化现场规模SAGD项目的性能。现有的蒸汽室开发速率模型将被改进，以考虑三相流的物理特性，这是基于蒸汽的in-stue采收过程中不可避免的现象。** 这项研究的结果将由两名博士和两名硕士学生进行，预计将提高对蒸汽，水和油在多孔介质中同时流动时发生的复杂动态现象的理解。在存在蒸汽冷凝现象的情况下对三相油相对渗透率进行建模是一个具有挑战性的问题，将在拟议的研究计划中通过进行仔细的实验室测量来研究。除了科学影响外，这项研究还将帮助石油工业估计作业后油藏中剩余的石油数量，并开发回收剩余石油的补充技术。预测和延长SAGD项目的经济寿命具有重要的战略意义，因为加拿大有许多成熟的SAGD蒸汽室，其中含有大量的石油和热能。因此，这项研究的结果将间接帮助该行业1）降低每桶石油生产的成本和环境影响。

The proposed research program develops a novel laboratory technique and procedure for fundamental study of three-phase flow in porous media. The measured data will be used for prediction and optimization of in-situ thermal recovery methods for oil production from Canada's heavy oil and bitumen resources. More than 300 billion cubic meters of viscous bitumen exist in Alberta and Saskatchewan. Only one-third of this huge resource is enough to meet the hydrocarbon requirements of all of North America for more than 100 years. However, only 20% of this resource is accessible through surface mining. The other 80% requires in-situ methods such as Steam Assisted Gravity Drainage (SAGD). SAGD has been proved to be the most successful in-situ recovery method for heavy oil and bitumen recovery in Canada. In SAGD, steam, steam-condensate, and oil simultaneously flow through the rock pore space. Mathematical modelling and optimizing such processes require careful measurement of flow conductance (relative permeability) and residual saturation of each phase in the laboratory. However, laboratory determination of relative permeability curves for steam, oil, and water is very challenging due to difficulties in phase saturation (i.e., volumetric fraction) measurement. The main challenge is to distinguish between the water and oil phases, which have similar densities. Phase A of this research develops a novel non-destructive method for measuring the saturation of oil, water and steam simultaneously flowing through a porous medium confined inside a core holder. In this method, the total oil and water saturation (So + Sw) is measured by a x-ray based technique, and water saturation (Sw) is measured by a capacitance (described by dielectric constant) based technique. The dielectric constant of water is several times higher than that of oil, which allows computing the fraction of each phase. The three-phase saturations measured in time and space will be interpreted and modelled to obtain three-phase relative permeabilities for each point in the saturation space. Phase B of the research develops mathematical techniques to use the measured data to evaluate, predict and optimize the performance of field-scale SAGD projects. The existing models for steam chamber development rate will be improved to account for the physics of three-phase flow, which is an inevitable phenomenon during steam-based in-stue recovery processes. **The results of this study, which will be conducted by two PhD and two MSc students is anticipated to develop an improved understanding of complex dynamic phenomena occurring during simultaneous flow of steam, water, and oil in porous media. Modelling three-phase oil relative permeability in the presence of steam condensation phenomenon is a challenging problem, which will be studied by conducting careful laboratory measurements in the proposed research program. In addition to the scientific impacts, this research will help the oil industry to estimate the amount of oil remaining in the reservoir after the operations and to develop complementary techniques for recovering the remaining oil. Predicting and extending the economic life SAGD projects are important strategically since there are many mature SAGD steam chambers in Canada containing a significant amount of oil and heat energy. Therefore, the outcomes of this research will help the industry indirectly to 1) reduce the cost and environmental impacts per barrel of oil produced.