【作者】 张琴； 陈文玲； 李沁； 罗志彬； 郑环；

【Author】 Energy College of Chengdu University of Technology;National Key Laboratory of Reservoir Geology and Development (Chengdu University of Technology);

【机构】 成都理工大学能源学院； 油气藏地质及开发全国重点实验室(成都理工大学)；

【摘要】 随着油气资源开发日益深入,复杂的埋藏地质条件需要高效的压裂措施对储层进行改造,水力压裂需要有高导流能力的裂缝,而支撑剂对于高导流裂缝而言意义突出,支撑剂在粗糙裂缝中输送的影响规律能实现压裂的优选。本文基于分形插值曲面理论,通过改变支撑剂参数、裂缝参数,利用fluent建立不同密度砂浓度等下的粗糙裂缝数值模型,通过设计这一系列的案例进行研究,采用CFD-DEM耦合计算方法,对粗糙裂缝中支撑物的运移进行了数值模拟。采用控制变量法,对支撑剂密度、粒径宽度比、砂浓度进行了研究,定性揭示了不同裂缝、支撑剂和流体参数对粗糙裂缝中支撑剂输送的影响。结果表明,随着支撑剂密度从1450kg/m~3到1850kg/m~3再到2250kg/m~3越来越大,支撑剂受到的互相干扰越来越小,单个颗粒速度大小的变化也趋于稳定;采用不同颗粒大小的填料,粒径缝宽比选在0.15～0.35间有最优的配比,从而可以达到最大渗透率;砂浓度为在选定的50kg/m~3、100kg/m~3、150kg/m~3中砂浓度为150kg/m~3时受到的干扰最大。本研究结果对于粗糙裂缝内支撑剂动态铺置、缝内支撑剂的高效填充而言意义突出。更多还原

【Abstract】 For now, there are lots of theoretical studies on proppant migration law of fracture at home and abroad, but the monitoring technology of fracture is not perfect, and the observation data obtained in field construction can not provide a reasonable explanation for proppant fracture paving section.Based on the fractal interpolation surface theory, the numerical model of rough cracks under different sand densities was established by Fluent by changing proppant parameters and fracture parameters. A series of cases were designed and studied, and the migration of supports in rough cracks was numerically simulated by CFD-DEM coupling calculation method. The control variable method was used to study proppant density, particle size/width ratio, sand concentration, and the effects of different fracture, proppant and fluid parameters on proppant transportation in rough fractures were revealed qualitatively.The results show that with the increase of proppant density, the interaction of proppant becomes less and less, and the change of individual particle velocity tends to be stable. The maximum permeability can be achieved by using fillers of different particle sizes, and the optimum ratio of slit width between 0.15 and 0.35 is obtained. When sand concentration is 150 kg/m~3 among the selected 50 kg/m~3, 100kg/m~3 and 150 kg/m~3, the interference is the largest.The results of this study are significant for dynamic proppant placement and efficient proppant filling in rough fractures.更多还原