Method for predicting post-fracking pressure build-up in shale

Abstract

During fracking processes, fluid is injected into the injection wells to cause micro-fractures in the shale. Contact between shale and water causes the development of micro-fractures. Given the deep location of the injection wells, the water is under high pressure that can build up over time and could potentially cause tremors. Based upon experiments on Pierre shale, it has been determined that the appearance of micro-fractures in shale begin with the saturation of capillaries, followed by ionic and diffusive transport of water into the shale clays. Using this discovery, a method for predicting the post-fracking pressure build-up in shale is disclosed.

I claim: 
     
         1 . A method for increasing gas and liquid production in post-fractured shale, comprising:
 (a) saturating the capillaries in the post-fractured shale with fluid;   (b) determining the hydraulic potential of the fluid;   (c) determining the chemical potential of the fluid;   (d) determining the bond dissociation energy of the post-fractured shale;   (e) using the bond dissociation energy to determine the Gibbs free energy;   (f) monitoring the initiation of additional pore pressure in the post-fractured shale capillaries;   (g) monitoring the initiation of random micro-fractures in the post-fractured shale; and   (h) collecting increased gas or liquid production.   
     
     
         2 . The method of  claim 1 , wherein the fluid applied is freshwater or low quality steam. 
     
     
         3 . The method of  claim 1 , wherein the fluid applied is water with included additives. 
     
     
         4 . The method of  claim 3 , wherein the additives added to the fluid comprises sand particles.