Improving the Functionality of Hydraulic Fracturing Fluid with the Possibility of Self-Generation of Proppant in Fractures

Abstract Increasingly, modern trends in the oil and gas industry are leading to a significant number of studies aimed at functionally changing hydraulic fracturing technology, proposing a transition from traditional solid proppants to the creation of a single form of fracturing fluid and proppant, based on a synthetic material in liquid form and subsequent in-situ generation. Problems that are often encountered during hydraulic fracturing with traditional proppants include proppants settling near the wellbore and leaving a large surface of the fracture unsupported, improper placement of proppant in fractures of varying lengths and diameters, and the migration of conventional proppants within the fracture is always limited due to the small width of the fracture and the rigid structure of the proppant, among other difficulties. The approach chosen in this work is the production of a self-generating proppant, capable of transforming from a liquid form to a solid form at temperatures above 50 °C, based on cross-linked homopolymer isocyanurates that perform the proppant function and, under reservoir conditions, harden in situ in an existing or formed fracture to form microspheres, with the ability to maintain fluid flow channels open and, accordingly, with the ability to transport fluid extracted from the fractures to the production well. The conducted studies show satisfactory strength of the obtained self-generating proppant, determined in a crushing test under increased pressure, where one of the traditional proppants was used as a comparative material. Another criterion for the optimality of a system consisting of self-generating proppant is that, when combined with a fracturing fluid based on synthetic gels and synthetic proppant, a low-viscosity system with high viscoelastic properties can be created, reducing the risk of formation contamination. Thus, in this study, conductivity tests showed that the proppant pack composed of self-generating proppant exhibits high potential. A comparison with traditional proppant shows that the synthetic proppant microspheres exhibit high regained conductivity after exposure to low-viscosity polyacrylamide gels, which can be used in conjunction with the proppant. The use of the selected system as a new agent in the oilfield market significantly expands the possibilities for individual system selection, where it is possible to simultaneously use fracturing fluids with optimal performance properties and a form of proppant capable of generation in the reservoir.