支撑剂在超临界二氧化碳中的跟随性计算

发布时间：2018-05-14 16:15

本文选题：超临界二氧化碳 + 压裂液携砂　；参考：《石油学报》2016年08期

【摘要】：超临界二氧化碳作为一种新型压裂液,是目前国内外的研究热点,但其携砂机理尚不明确,成为制约该项技术的关键问题之一。将跟随性的概念引入压裂液携砂研究,以支撑剂水平速度和压裂液水平流速的比值来表征支撑剂的跟随性或压裂液的携砂性能,并以跟随性为标准,对超临界二氧化碳的水平携砂性能进行了评价。在经典BBO方程的基础上,改进了拖曳力的表达式,联立拖曳力系数辅助方程组,建立了支撑剂在超临界二氧化碳中的跟随性计算模型,为评价和优化超临界二氧化碳输送支撑剂提供了理论依据。采用自主研发的实验设备,通过跟随性实验对该模型进行了检验,并采用模型进行了支撑剂在超临界二氧化碳中跟随性的影响因素分析。研究结果表明,在常用密度范围内,支撑剂密度对跟随性的影响不大,该数值分析结论与以往学者的实验研究结果相一致。此外,对比了砂粒在超临界二氧化碳、滑溜水以及空气中的跟随性,超临界二氧化碳的高密度特性对其携砂性能的影响大于低黏度特性对其携砂性能的影响,两者综合作用导致其携砂性能远高于空气,小于并接近滑溜水的携砂性能,特别是在较高流速下,超临界二氧化碳的水平携砂性能与滑溜水相当。
[Abstract]:As a new type of fracturing fluid, supercritical carbon dioxide is the research hot spot at home and abroad, but its sand carrying mechanism is not clear, and it has become one of the key problems that restrict this technology. The concept of follower is introduced into the study of fracturing fluid carrying sand to characterize the follower of proppant by the ratio of the horizontal velocity of the proppant to the horizontal velocity of the fracturing fluid or the ratio of the horizontal velocity of the fracturing fluid. On the basis of the classical BBO equation, the expression of the drag force is improved and the combined drag coefficient auxiliary equation group is established on the basis of the classical BBO equation. The calculation model of the follower of the proppant in the supercritical carbon dioxide is set up, and the evaluation and optimization are made for the evaluation and optimization. A theoretical basis was provided for the supercritical carbon dioxide transport support. The model was tested by the experimental equipment developed by ourselves, and the model was used to analyze the influence factors of the proppant following the supercritical carbon dioxide. The results showed that the density of the proppant was on the heel in the range of common density. In addition, the results of the numerical analysis are consistent with the experimental results of previous scholars. In addition, the following properties of sand particles in supercritical carbon dioxide, slippery water and air are compared. The influence of the high density characteristics of supercritical carbon dioxide on the performance of sand carrying capacity is greater than that of low viscosity on its sand carrying property. As a result, the performance of the sand carrying capacity is much higher than that of the air, which is less than and close to the sand carrying capacity of the sliding water, especially at the high velocity, the horizontal sand carrying capacity of the supercritical carbon dioxide is equivalent to the sliding water.

【作者单位】：中国石油大学石油工程学院;中国石油化工股份有限公司石油工程技术研究院;The
【基金】：国家自然科学基金联合基金重点项目“非常规天然气储层超临界二氧化碳压裂工程基础研究”(No.U1262202)和国家自然科学基金国际合作重点项目“页岩气藏水平井完井与多级压裂增产的基础研究”(No.5121006)资助
【分类号】：TE357.12

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