Development of degradable fiber slickwater system and enhanced proppants-carrying mechanism

Abstract

Slickwater fracturing fluid has become one of the most popular fracturing fluids due to its low frictional resistance and cleanness. However, slickwater has limited proppants-carrying ability because of its low viscosity. It often leads to proppants deposition in the near-wellbore and even sand plug. Simultaneously, it is impossible to transport the proppants to the distal end of the fractures, affecting the hydraulic fracturing effect. In this work, a degradable fiber slickwater fracturing fluid is innovatively constructed to carry proppants better. The adopted fibers have excellent degradability, no formation residues after complete degradation, and low reservoir damage. A series of rheological experiments are conducted to investigate the rheology of the fiber slickwater. Static proppants-carrying experiments and large visual dynamic proppants-carrying equipment simulate the proppants-carrying process in the reservoir to investigate its proppants-carrying performance. The fiber slickwater has the stronger structure than pure slickwater, the zero-shear viscosity can be enhanced by 20-1000 times, and the viscoelasticity is significantly improved. The dynamic proppants-carrying results show that the amount of proppants residue in the near-wellbore is reduced dramatically, and the proppants are laid more uniformly. About 11.8% of the proppants are delivered to the distal end. Finally, scanning electron microscope and electron microscope characterizations are used to reveal the proppants-carrying mechanism. This endeavor will develop a novel proppants-carrying concept for slickwater fracturing fluid.