Investigating Multiphase Flow in Shales by Measuring Relative Permeabilities for Sustainable Hydrocarbon Recovery

拟议的研究计划将开发新的实验室和数学技术，以研究和模拟孔隙尺度上的相分布、岩心尺度上的相相对渗透率(流动电导)和现场尺度上的多相产量。在自然界中，页岩作为1)生烃的源岩；2)自生生烃的储集岩；以及3)封闭常规储集岩或地下储集场所的盖层。了解页岩中多相流的物理机制是模拟原生油气从源岩到储集岩的运移、在上覆页岩中储存温室气体和废物以及从页岩储集层中生产油气的关键。目前，由于页岩极低的孔隙度和渗透率以及复杂的孔隙结构，目前还没有测量页岩相对渗透率的实验室方法。这项研究将在两个相辅相成的实验和建模阶段进行。在A阶段的第一部分，将通过1)分析扫描电子显微镜图像和2)测量和分析岩心样品中的相渗吸、熔融、冻结和蒸汽冷凝来表征各种加拿大页岩样品的亲水和疏水孔隙的尺寸分布。然后，进行一系列特殊的共驱实验，通过控制吸液时间、蒸汽压力或岩心温度，在超低流量和不同饱和度条件下测量相相对渗透率。A相的测量数据将在B相进行数学分析，以模拟代表页岩样品疏水和亲水孔隙的混合-湿孔网络。然后，我们将模拟油酸、水和气相在孔隙网络中的流动，以计算相对渗透率曲线，并将其与A相的测量结果进行比较。测量和建模的数据将用于评估、预测和优化油田规模页岩开发项目的绩效。这一研究项目的结果将由3名博士和2名硕士学生进行，将加深对有机页岩中水、油和天然气同时流动时发生的复杂动态现象的理解。除了科学影响外，这项研究还将帮助石油行业估计作业后页岩油藏中剩余的石油数量，并开发开采剩余石油的补充技术。预测和延长页岩和致密油项目的经济寿命具有重要的战略意义，因为加拿大有许多模拟致密非常规油藏含有大量剩余油。这可能会减少钻探更多油井的需要。因此，这项研究的结果将间接帮助该行业降低每桶石油生产的成本和对环境的影响。

The proposed research program will develop novel laboratory and mathematical techniques to study and model phase distribution at the pore-scale, phase relative permeability (flow conductance) at the core scale, and multi-phase production rate at the field scale of shale reservoirs. In nature, shales serve as i) source rocks generating hydrocarbon; ii) reservoir rocks self-generating and producing hydrocarbon, and iii) cap rocks sealing conventional reservoir rocks or underground storage sites. Understanding the physics of multiphase flow in shales is the key for modelling primary hydrocarbon migration from source to reservoir rocks, storing greenhouse gases and waste materials in overlying shales, and producing hydrocarbon from shale reservoirs. Currently there is no laboratory protocol for measuring relative permeability of shales mainly because of their extremely low porosity and permeability and complex pore structure. The research will be conducted in two complementary experimental and modelling phases. In the first part of Phase A, size distributions of hydrophilic and hydrophobic pores of various Canadian shale samples will be characterized by 1) analyzing scanning electron microscopy images and 2) by measuring and analyzing phase imbibition, melting, freezing, and vapor condensation in core samples. Then, a series of special coreflooding tests will be conducted to measure phase relative permeability under ultra-low flowrate and under different saturation conditions achieved by controlling liquid imbibition time, vapor pressure, or core temperature. The measured data of Phase A, will be mathematically analyzed in Phase B, to simulate mixed-wet pore networks representing hydrophobic and hydrophilic pores of the shale samples. Then, we will simulate the flow of oleic, aqueous, and gaseous phases through the pore networks to calculate the relative permeability curves and compare them with those measured in Phase A. The measured and modelled data will be used to evaluate, predict, and optimize the performance of field-scale shale-development projects. The results of this research program, which will be conducted by 3 PhD and 2 MSc students, will develop an improved understanding of complex dynamic phenomena occurring during simultaneous flow of water, oil, and gas in organic shales. In addition to the scientific impacts, this research will help the oil industry estimate the amount of oil remaining in shale reservoirs after the operations and develop complementary techniques for recovering the remaining oil. Predicting and extending the economic life of shale and tight oil projects is important strategically since there are many stimulated tight unconventional reservoirs in Canada containing a significant amount of residual oil. This will potentially reduce the need to drill more wells. Therefore, the outcomes of this research will help the industry indirectly to reduce the cost and environmental impacts per barrel of oil produced.