Effect of Proppant Size and Surface Characteristics on the Critical Velocity Required for the Effective Transport of Proppants in Hydraulic Fracturing of Horizontal Wells

支撑剂输送效率是水力压裂作业的一个关键方面。必须正确放置支撑剂以保持裂缝张开并增加油气产量。工业上最广泛使用的支撑剂是高密度颗粒，如砂和陶瓷。这些重颗粒沉积在水基流体中，要想将它们安置到裂缝中，就需要高强度的泵送功率和大量的水基流体，以确保这些重颗粒进入油藏的指定区域。虽然化学物质被用来使压裂液粘稠，以促进颗粒的输送，但化学物质的使用是不可取的。滑溜水（非粘滞流体）含有最少的化学物质，是水力压裂作业的首选之一，但由于支撑剂在这些流体中沉淀，在实现高效支撑剂输送方面遇到了困难。基于该项目的研究结果，进一步了解支撑剂运移背后的驱动因素（即近壁湍流、流体流变特性、支撑剂尺寸、密度和表面特征等），将有助于设计最佳压裂作业，从而确保支撑剂的正确放置，避免过早沉降和筛选支撑剂。这将有助于开发新的、更可靠的支撑剂表面改性产品，从而实现更高效、更安全的压裂作业设计，从而提高油藏产量。加拿大油气行业开展更高效、更经济的水力压裂作业的能力将从这项拟议的研究中受益匪浅。改善支撑剂运输的好处可能会减少作业中的水和能源消耗。此外，改进的滑溜水压裂作业将减少水力压裂市场的化学用量，对加拿大的环境有积极的好处。

Proppant transport efficiency is a critical aspect of hydraulic fracturing operations. Proppants must be properlyplaced to hold fractures open and enable increased hydrocarbon production. Proppants most widely used byindustry are high density particles like sand and ceramics. These particles settle down in water-based fluids andtheir placement to fractures becomes a task that requires high intensity pumping power and large amount ofwater-based fluids to ensure these heavy particles travel to specified zones in the reservoir. Although chemistryis used to viscosify fracking fluids to facilitate transport of particles, the use of chemicals is not desirable.Slickwater (non-viscosified fluid) contains a minimum amount of chemicals and is one of the preferred optionsfor hydraulic fracturing operations but difficulties are encountered in achieving efficient proppant transport dueto proppant settling in these fluids. An improved understanding of the drivers behind proppant transport (i.e.near wall turbulence, fluid rheological properties, proppant size, density, and surface characteristics, etc.) basedon the results from this project, will be useful for designing optimum fracturing operations which ensuresproper placement of proppants by avoiding premature settling and screening of proppants. This will helpdeveloping new, more reliable proppant surface modification products, resulting in more efficient and securefrac job designs for improved reservoir production. Canada's Oil and gas industry's capacity to conduct moreefficient and economical hydraulic fracturing jobs will benefit tremendously from this proposed study. Thebenefits in improved proppant transport will potentially lead to reduction of water and energy consumption inthe operations. In addition, improved slick-water fracturing jobs will result in use of less chemistry in thehydraulic fracturing market with positive environmental advantages for Canada.