Novel methodology to reduce the strength of high stress-tight gas reservoirs using thermochemical

Formation breakdown failure is one of the major challenges that operators face when fracking tight and high stress reservoirs. Several lost potentials are recorded worldwide due to high breakdown pressure that exceeds pumping limitations or completion rating. Increasing the injection rate of the fluid into the rock corresponded to a lowering of the breakdown pressure. The higher injection rate allows more fluid to enter the shale porosity thus transmitting the injection pressure to more points within the shale formation, which reduces the breakdown pressure. The developed methodology reduces breakdown pressure and enables fracking high stress rocks by increasing the injectivity prior to fracturing. Thermochemical will be injected to create microfractures, improve permeability, and reduce young’s modulus of tight reservoirs prior to fracking. By creating microfractures and improving injectivity, the required breakdown pressure will be reduced, and fracturing will be enabled. Moreover, experimental results showed that thermochemical treatment reduces young’s modulus of the rock, thus reducing rock stiffness.