不同粒径玻璃微珠支撑剂在煤层中的运移规律研究

Study on Migration Patterns of Glass Microsphere Proppants at Different Particle Sizes within Coal Seams

摘要: 煤层气作为优质的清洁能源，在当今能源结构中日益重要。其增产开发主要依赖水力压裂技术，但该技术存在压裂裂缝易闭合、常闭合的不足。支撑剂作为水力压裂的关键材料，核心作用在于压裂液退出后仍能维持裂缝张开，形成高导流能力的通道。为此，本文以玻璃微珠为支撑剂展开研究，重点探究其在复杂裂缝条件下不同粒径的运移规律。采用控制变量法，以支撑剂粒径为变量，利用压裂支撑剂输送及铺砂模拟装置开展了系统的运移实验。结果表明，较大粒径(250~550 μm)的玻璃微珠支撑剂在主裂缝及无角度水平裂缝中表现出更优的填充效果；较小粒径(120~160 μm)的支撑剂则更适用于有角度的分级裂缝；总体而言，主裂缝和水平裂缝的支撑剂填充率随粒径减小而降低；对于一级和二级裂缝，填充效果最佳的支撑剂粒径范围为160~250 μm。

Abstract: Coalbed methane, as a high-quality clean energy source, is assuming increasing importance within contemporary energy structures. Its enhanced recovery primarily relies on hydraulic fracturing technology, though this technique suffers from the shortcomings of fractures being prone to closure and exhibiting persistent closure. Proppants, as critical materials in hydraulic fracturing, play a pivotal role in maintaining fracture openness after fluid withdrawal, thereby creating highly conductive pathways. This study therefore investigates glass microspheres as proppants, focusing on the migration patterns of different particle sizes under complex fracture conditions. Employing a controlled variable method with proppant particle size as the variable, systematic migration experiments were conducted using a fracturing proppant delivery and sand placement simulation apparatus. Results indicate that larger-sized glass microsphere proppants (250~550 μm) exhibit superior filling efficiency within primary fractures and angle-free horizontal fractures; whilst smaller-sized proppants (120~160 μm) proved more suitable for angled, multi-level fractures. Overall, proppant filling rates in both primary and horizontal fractures decreased with decreasing particle size. For primary and secondary fractures, the optimal proppant size range for filling efficiency was 160~250 μm.