Property Evaluation of Novel Micro-proppant for Shale Oil and Gas Reservoir Fracturing

Hydraulic fracturing technology is an effective measure to increase production of shale oil and gas. After hydraulic fracture is formed, the addition of proppant can ensure the fracture to open for a long time and form an oil and gas diversion channel. However, many conventional proppants have large particle size and fast settling speed, so they can't enter tiny fractures or can't be transported to the far end of fractures, and some production capacity is lost. Effective support for micro-fractures is the key to further improve shale oil and gas productivity. Therefore, in this study, the properties of four new micro-proppant materials, bauxite, α-alumina, silica and silicate, with average particle size less than 30 μm were evaluated and compared with 70/140 mesh quartz sand. The static suspension ability of micro-proppant is much better than that of conventional 70/140 mesh quartz sand, and it can be suspended for 72 h in 15 mPa·s fracturing fluid. Among them, silica and silicate micro-proppants are evenly dispersed in fracturing fluids with different viscosities, while bauxite and α-alumina are easy to agglomerate, and the dispersion ability is improved after surface treatment. Four kinds of micro-proppants can resist acid and alkali, and have certain conductivity, filtration loss reduction and pressure bearing capacity. In addition, SEM, XRD, density and laser particle size analyzer were also tested. The evaluation results of four new micro-proppant materials all have field application ability, which can provide reference for theoretical research and field test of shale oil and gas development.