变注入参数对裂缝内支撑剂铺置形态影响研究

Study on the Effect of Variable Injection Parameters on Proppant Placement Morphology in Fractures

摘要: 本文围绕水力压裂中裂缝内砂床形态预测这一重点和难点问题展开研究。目前支撑剂运移实验数据参数变化单一，与现场实际施工工况存在一定偏差，难以真实反映储层条件下支撑剂的运移铺置规律，支撑剂铺置形态的演化亟需深入研究。为此，本文基于可视化平行板物理实验与双流体数值模拟相结合的方法，建立了裂缝内支撑剂运移铺置实验模型。并且提出了一套用于砂床形态特征参数提取的方法，该方法能够在支撑剂运移连续时刻下实现自动化的特征提取和定量分析，探究支撑剂砂床形态特征及其变化规律。在此基础上，系统研究了单一注入参数以及组合参数变化对砂床铺置形态的影响规律，揭示了各参数对砂床形态的差异化影响机制。研究结果为水力裂缝内支撑剂砂床形态的预测和压裂施工参数优化提供了新的方法和理论依据，进而推动水力压裂技术的进步。

Abstract: This paper addresses the prediction of sand bed morphology in hydraulic fractures, a key and challenging issue in hydraulic fracturing. Existing proppant transport experimental data are mostly obtained by varying a single parameter, which deviate from actual field operating conditions and thus cannot faithfully reflect the proppant transport and placement behavior under reservoir conditions. The evolution of proppant placement morphology therefore requires further in-depth investigation. To this end, an experimental model for proppant transport and placement in fractures is established by combining visualized parallel-plate physical experiments with two-fluid numerical simulation. Furthermore, a method for extracting morphological characteristic parameters of the sand bed is proposed, which enables automated feature extraction and quantitative analysis at successive time instants during proppant transport, allowing the morphological characteristics and evolution of the proppant sand bed to be systematically explored. On this basis, the effects of individual injection parameters and their combined variations on sand bed placement morphology are systematically studied, and the differential mechanisms by which each parameter influences sand bed morphology are revealed. The results provide new methods and a theoretical basis for predicting proppant sand bed morphology in hydraulic fractures and optimizing fracturing treatment parameters, thereby promoting the advancement of hydraulic fracturing technology.