Study on Distribution of Low Density Proppants in Hydraulic Fracturing Operations and the Application Thereof

In hydraulic fracturing operations, the distribution of proppants in the fractures play an important role to the results of the stimulation job. Laboratory experiments have been conducted to study the distribution of settled sand bank of low density proppants in fresh water, in 0.08% HPG solution and 0.3% HPG solution, three solutions with different viscosity, at different flowrates (1, 2, 4 and 6 m³/h, respectively) and different sand/liquid ratios (5%, 10%, 15% and 20%, respectively). Calculating of the experimental data with linear fitting showed that the horizontal migration velocity of the proppants increases with flowrate of the liquid, contrary to the vertical migration speed of the proppants. A "fluctuation" phenomenon was observed during the settling of proppant. At low flowrate (less than or equal to 0.5 m/s) of the liquid at the opening of a fracture, the horizontal migration velocity of proppants is increasing fast. At high flowrate (greater than 0.5 m/s) of the liquid at the opening of a fracture, the increase of horizontal migration velocity of proppants is slow down. Field test have been done on three wells using low density proppants, the average open-flow capacity was 28.015×10⁴ m³/d, 1.91 times of the flowrate of offset wells. The test results provide good guidance to hydraulic fracturing operations.