EAGER: Pickering Emulsions for Hydraulic Fracturing Applications

在水力压裂中，高压是用来在页岩地层中诱发裂缝的。然后注入沙子和其他固体颗粒（称为支撑剂），以防止压力释放后裂缝坍塌。这些适当的裂缝有利于天然气/石油的开采。砂的缺点是在裂缝内分布不均匀，并且不能到达远离井筒的裂缝。这限制了从给定页岩地层中提取的天然气/石油的数量。材料科学领域正在进行研究，以生产出尺寸均匀（这样它们就不会堵塞裂缝）、体积小（这样它们就可以穿透狭窄的裂缝）、机械强度高（即使暴露在高地下压力下也能保持裂缝畅通）、重量轻（扩散到离井筒更远的地方，从而可以从一条裂缝中提取更多的天然气/石油）的支撑剂。该方案旨在探索皮克林乳剂是否可以用于防止压力释放后水力裂缝的坍塌。皮克林emulsionse.g。（油中的水）被固体颗粒稳定。它们在食品制备、化妆品、药物输送和催化过程等各个领域都有广泛的应用。到目前为止，在PIs实验室获得的结果，在叙述中总结，已经获得了散装皮克林乳剂。这些研究量化了固体颗粒对水-癸烷界面张力的影响，以及液滴聚结的机理。目前正在进行的研究是为了阐明由不同固体颗粒混合物组成的系统的界面结构和动力学性质。这一建议源于一种假设，即乳剂可以更好地控制裂缝内支撑剂的分布，可能远离井筒。在相关体系中，支撑剂将具有裂缝稳定剂和破乳剂的双重作用。预计一旦乳状液由于颗粒与岩石的相互作用而变得不稳定，支撑剂就会吸附在岩石表面。通过控制不同地下地层中的乳液稳定性，可以设计出针对页岩的支撑剂。该研究的智力价值在于评估了在水力裂缝中注入支撑剂的新方法（皮克林乳液代替水分散体）。如果成功，这项探索性研究可能会导致页岩地层中储存的大量天然气/石油的开采。更广泛的影响。一名博士后将进行为期一年的探索性研究。所得结果将用于检验我们的假设。如果成功，这项研究将为国家带来巨大的经济效益，因为水力压裂阶段是钻井过程中最昂贵的阶段之一，而且单口井将生产更多的天然气。我们的研究也将对其他技术（如化妆品和药物输送）产生潜在的影响，因为我们的研究将导致对pickeringemulsion更好的基础理解。研究结果将根据我们的记录整合到教学和外展活动中。

In hydraulic fracturing high pressures are applied to induce fractures within shaleformations. Sand and other solid particles (known as proppants) are then injected toprevent the collapse of the fractures once the pressure is released.These proppedfractures ease the extraction of natural gas/oil. Sand has the disadvantages of notdistributing evenly within the fractures, and of not reaching fractures far from thewellbore. This limits the amount of natural gas/oil that can be extracted from a givenshale formation. Research is being conducted in materials sciences to produceproppantsthat are uniform in size (so that they will not clog the fractures),small (so that they canpenetrate narrow fractures), mechanically strong (to maintain the fractures open evenwhen exposed to high subsurface pressures), and light (to diffuse farther from thewellbore, allowing the extraction of larger amounts of natural gas/oil from one fracture).This proposal intends to explore whether Pickering emulsions could be used to preventthe collapse of the hydraulic fractures once the pressure is released. Pickering emulsionse.g., water in oil) are stabilized by solid particles. They find numerous applications inareas as diverse as food preparation, cosmetics,drug delivery, and catalytic processes.The results obtained so far in the PIs laboratory,summarized in the narrative, have beenobtained for bulk Pickering emulsions.Such studies have quantified the effect of solidparticles on the water-decane interfacial tension, and the mechanism of dropletcoalescence.Current research is being conducted to clarify the interfacial structure anddynamical properties for systems composed by mixtures of different solid particles.This proposal stems from the hypothesis that emulsions might allow for a bettercontrolled distribution of the proppants within a fracture, possibly far from the wellbore.In the systems of interest the proppants will have the dual role of fracture stabilizers andemulsion formers.It is anticipated that once the emulsions are destabilized because ofparticle-rock interactions,the proppants will adsorb onto the rock surface.By controllingthe emulsion stability within different sub-surface formations it will be possible to design shale-specific proppants.The intellectual merit of the proposed research consists in the evaluation of a newmethod to inject proppants within hydraulic fractures (Pickering emulsions instead ofaqueous dispersions). If successful, this exploratory research could lead to theexploitation of larger amounts of the natural gas/oil stored in shale formations.Broader impacts. One post-doctoral researcher will conduct this exploratory researchover a period of one year. The results obtained will be used to test our hypothesis. Ifsuccessful, the proposed research could bring enormous economical advantages to thenation because the hydraulic fracturing stage constitutes one of the most expensive stagesin the well drilling, and because more natural gas will be produced from a single well.Potential impacts are also expected on other technologies (e.g., cosmetics and drugdelivery),as our research will lead to better fundamental understanding of Pickeringemulsions. The research results will be integrated in teaching and outreach activities,following our track record.