Application of PGA Fiber and Fluid-loss Materials To Slick Water Fracturing

摘要

In recent years, service companies often use a low viscous, fiber-laden fracturing fluid. The added fibers not only assist in the transport of proppant based on mechanical suspension but also prevent proppant settling during fracture closure. Although the chemical composition of the fibers used is not described, their characteristics suggest that they are made of PLA materials. In our experiments, we tested both PGA and PLA fibrous materials using a small scale slotted equipment. The results showed that mixing fibers with a small amount of polymer significantly helped transporting proppant. From the preliminary tests, PLA fibers crumbled and tended to induce proppant screen-out often; thus, only PGA materials were used for the proppant transport experiments. Since the PGA materials were cost prohibitive, we determined the optimum concentration of PGA fibers by changing the polymer concentration of frac fluid and injection rate. We concluded that the suitable amount of fibers is around 0.567 kg (1.25 lbs)/ 3785.4 liters (1000 gallons) of slick water. This concentration is economically feasible given that the total fluid injection volume is large for hydraulic fracturing applications.