Research and Application of the Gel Breaking in Fracture Technology

In the course of Water-based polymer fracturing fluid sand fracturing, in order to make fracturing fluid breaking and flowback, we often need to add a certain amount of gel breaker.Currently, persulfate, capsule and the technology of wedge-shaped mixing have been widely used as an ordinary breaker, however, there is still residual gum fracturing fluid damage.Therefore, This paper researches on a new gel-breaking technology based on persulfate breaker by laboratory experiment, and successfully developed a completely breaking fracturing fluid combination technology-the technology of gel breaking in fracture.To compare the fracturing fluid which used this technology (fracturing fluid gel breaking in fracture) with the conventional fracturing fluid, we found that the maximum residue molecular weight of fracturing fluid gel breaking in fracture is 6 ~ 8 times lower than conventional fracturing fluid, and at the same time, the permeability of core damage reduced by 30%~40%.there are five wells with the the technology of gel breaking in fracture and five wells of conventional fracturing fluid gel-breaking application tests in GA block B area of Sichuan, the results show that fracturing fluid with the technology of gel breaking in fracture average rate of return is about 10% higher than conventional fracturing fluid, and an average single-well test production of natural gas increases by 2 to 3 times.