Optimization on particle size fraction of lightweight coated ceramsite proppant in coal reservoir

Hydraulic fracturing is currently one of the main technical measures for enhancing coal reservoirs permeability. The spreading range and transportation distance of proppants in the fracture is an important indicator of hydraulic fracturing to evaluate fracturing effect. According to the characteristics of coal reservoirs in Lu’an mining area, physical experiments and numerical simulation methods are used to compare and analyze the effects of fracture conductivity, sand spreading range, particle size combination and other factors on conductivity of coalbed methane wells, and the best proppants particle size and particle size ratio are selected. The research results indicate that the fracture conductivity of proppants decrease with the increasing closure pressure. The length of the coated light ceramsite proppants in the cracks of the sand embankment and sand paving area is nearly twice that of ordinary quartz sand. Among the three sizes of 40-60 mesh, 16-40 mesh, and 12-20 mesh coated lightweight ceramsite, the 12-20 mesh fracturing fracture length, supporting fracture length and average proppants concentration are the smallest, while the conductivity is the highest; when ratio of particle size for 40-60 : 16-40 : 12-20=1 : 6 : 2, the best fracturing range was obtained by using coated lightweight ceramsite with an average fracture length of 320 m, fracture width of 0.672 cm, proppants concentration of 5.16 kg/m² and fracture conductivity of 1.263.