APPLICATION OF SUPERABSORBENT POLYMERS FOR PRESSURE REGULATION AND DIVERTING APPLICATIONS

摘要

FIELD: mining.;SUBSTANCE: present invention relates to the use of superabsorbent polymers for controlling pressure and diverting applications in treating a subterranean formation, including hydraulic fracturing. Method of hydraulic fracturing a subterranean formation through which a wellbore passes includes providing a diverting liquid containing a carrier fluid, a first superabsorbent polymer and a second superabsorbent polymer, wherein the second superabsorbent polymer has a shape or composition, or a combination thereof, different from those of the first superabsorbent polymer, pumping a diverting liquid into a subterranean formation and pumping a fracturing fluid into the formation after pumping a diverting fluid, the flow of the fracturing fluid is hampered by the first and second superabsorbent polymers, the first and second superabsorbent polymers are selected such that the diverting liquid containing them has an improved diverting efficiency compared to the reference diverting fluid, containing a first superabsorbent polymer or a second superabsorbent polymer. Method of hydraulic fracturing a subterranean formation in another embodiment, comprising providing a deflecting liquid containing a carrier fluid, a superabsorbent polymer and a viscosity modifying agent effective to increase the viscosity of the deflecting fluid at a shear rate of 100 s^-1, pumping a diverting liquid into a subterranean formation, pumping a fracturing fluid into the formation after pumping a diverting fluid, where the flow of the fracturing fluid is hampered by the superabsorbent polymer and the diverting fluid has an improved diverting efficiency as compared to a reference diverting liquid containing a carrier fluid, a superabsorbent polymer, but not an agent for viscosity modification. Method of treating a borehole comprising circulating a composition forming a filter cake in a wellbore, wherein said composition comprises a superabsorbent polymer and a carrier fluid, forming filter cake on the surface of the formation to reduce or eliminate leakage of liquid, operation of the well, destruction of the superabsorbent polymer and removal of the filter cake. Invention is developed in dependent items of the formula.;EFFECT: higher efficiency of processing.;15 cl