薄煤层水力裂缝宽度变化对支撑剂运移的影响

The influence of hydraulic fracture width change on proppant transport in thin coal seam

陈捷 胡海洋 刘立 娄毅

贵州省煤层气页岩气工程技术研究中心，贵州 贵阳 550016 贵州省煤田地质局159队，贵州 六盘水 561600 贵州盘江煤层气开发利用
有限责任公司，贵州 贵阳 550009

Guizhou Research Center of Shale Gas and CBM Engineering Technology, Guiyang 550016, China No.159 Team, Guizhou provincial Coalfield Geological Bureau, Panxian 561600, China Guizhou Panjiang Coalbed Methane Development and Utilization Co., Ltd., Guiyang 550009, China

水力压裂仍是低渗透性储层提高渗透性且获得经济产能的主要途径，尤其针对薄煤层，不同裂缝宽度裂缝内支撑剂运移规律受多个因素影响。文中采用数据建模、数值模拟和工程试验的方式，研究了压裂液参数、支撑剂参数对不同裂缝宽度支撑剂的铺砂面积和有效支撑裂缝长度的影响。结果表明：裂缝宽度影响和制约了支撑剂的运移，对于裂缝较发育且缝宽较宽储层，提高施工排量、压裂液黏度和优化支撑剂粒径与砂比，能有效地增大裂缝内支撑剂的铺置面积和有效裂缝长度。针对裂缝不发育且裂缝宽度较小储层，优化支撑剂的粒径和砂比，有利于增大裂缝的有效支撑裂缝长度。针对薄—中厚煤层，采用“高前置液占比、小粒径支撑剂、低砂比、短段塞式加砂方式”，能够有效提高其压裂波及范围和有效支撑效果，研究成果成功应用于贵州薄煤层煤层气开发。

Hydraulic fracturing is still the main way to improve permeability and obtain economic productivity in low permeability reservoirs. Especially for thin coal seams, the migration law of proppant in fractures with different fracture widths is affected by many factors. By means of data modelling, numerical simulation and engineering test, in this paper, the effects of fracturing fluid parameters and proppant parameters on the sand area and effective propping length of proppant with different fracture widths are studied. The results show that the fracture width affects and restricts the migration of proppant. For reservoirs with more developed fractures and wider fracture width, increasing the construction displacement, fracturing fluid viscosity and optimizing the proppant particle size to sand ratio can effectively increase the proppant placement area and effective fracture length. For reservoirs with undeveloped fractures and small fracture widths, the optimization of proppant particle size and sand ratio is conducive to increasing the effective propping length of fractures. For thin to medium?鄄thick coal seams, the method of "high preloading liquid ratio, small particle size proppant, low sand ratio and short slug sand addition" can effectively improve its fracturing coverage and effective support effect, and the research results have been successfully applied to the development of thin coal seam gas in Guizhou.

10.6056/dkyqt202305004