Analysis of Proppant Transportation and Placement Law in Sand Mixing Process

Abstract

The study of proppant transport and placement is an important step to help optimize the fracturing design, improve the efficiency of oil and gas extraction, and reduce the environmental risk. In this paper, based on the indoor physical simulation experiments of hydraulic sand fracturing in Surig tight gas reservoir, we analyzed the proppant transport and placement law in the sand mixing process by comparing two sand mixing methods, namely, single grain size and combined ceramic grains, with the sand ratio, displacement, viscosity, and proppant type as the main controlling factors. The results show that single particle size can support the fracture near the wellhead zone in the pre-fracturing stage, and the larger the proppant particle size, the larger the sand ratio, the smaller the discharge, the smaller the viscosity of fracturing fluid, the higher the equilibrium height of sand dike formed in the process of transporting in the fracture. Therefore, in the experimental combined ceramic particles, the larger the proportion of large-size proppant is, the better the inflow ability, and the better the inflow ability would be. Considering the flow-conducting ability and economic cost, it is recommended to use the proppant combination ratio of 100/200 (quartz sand):70/140 (ceramic grains):40/70 (ceramic grains) = 1:3:7 for filling. The results of the study can be used to optimize the proppant formulation in Sourig tight gas reservoirs, to reduce the cost of fracturing operations and to improve the efficiency of hydrocarbon recovery in this type of reservoir.