Method for evaluating and monitoring formation fracture treatment using fluid pressure waves

Abstract

A method for characterizing a hydraulic fracture in a subsurface formation includes inducing a pressure change in a well drilled through the subsurface formation. At least one of pressure and pressure time derivative are measured in or at a location proximate to a wellhead for a selected length of time. At least one of a physical parameter, a time derivative, and a change in the parameter with respect to time of the physical parameter of at least one fracture is determined using the measured at least one of pressure and the time derivative of pressure.

What is claimed is: 
     
         1 . A method for predicting characteristics of a hydraulic fracture in a subsurface formation, comprising:
 inducing a pressure change in a well drilled through the subsurface formation;   determining at least one of a physical parameter, and a time derivative, and a change in the parameter with respect to time, of at least one fracture, using the measured at least one of pressure and the time derivative of pressure, and   correlating the at least one of a physical parameter, and a time derivative, and a change in the physical parameter with respect to time, of at least one fracture with at least one of a lithological description of the subsurface formation, and at least one characteristics of the manner in which the hydraulic fracture was created, and   predicting at least one of a physical parameter, a time derivative, and a change in the physical parameter with respect to time, of at least one fracture, to be created in another part of the same, or a similar, subsurface formation.   
     
     
         2 . The method of  claim 1  wherein the at least one of a lithological description of the subsurface formation, and at least one characteristics of the manner in which the hydraulic fracture was created comprises the pumping rate with which the hydraulic fracture was created. 
     
     
         3 . The method of  claim 1  wherein the at least one of a lithological description, or localized stress of the subsurface formation, and at least one characteristics of the manner in which the hydraulic fracture was created comprises the proppant concentration with which the hydraulic fracture was created. 
     
     
         4 . The method of  claim 1  wherein the at least one of a lithological description or localized stress of the subsurface formation, and at least one characteristics of the manner in which the hydraulic fracture was created comprises the silica content of the formation. 
     
     
         5 . The method of  claim 1  wherein the at least one of a lithological description or localized stress of the subsurface formation, and at least one characteristics of the manner in which the hydraulic fracture was created comprises the calcium content of the formation. 
     
     
         6 . The method of  claim 1  wherein the at least one of a lithological description or localized stress of the subsurface formation, and at least one characteristics of the manner in which the hydraulic fracture was created comprises the temporal changes in pumping rate with which the hydraulic fracture was created. 
     
     
         7 . The method of  claim 1  wherein the at least one of a lithological description or localized stress of the subsurface formation, and at least one characteristics of the manner in which the hydraulic fracture was created comprises the temporal changes in proppant concentration with which the hydraulic fracture was created. 
     
     
         8 . The method of  claim 1  wherein the at least one of a lithological description or localized stress of the subsurface formation, and at least one characteristics of the manner in which the hydraulic fracture was created comprises the temporal changes in proppant type (size, hardness, abrasive properties, etc.) with which the hydraulic fracture was created. 
     
     
         9 . The method of  claim 1  wherein the at least one of a lithological description or localized stress of the subsurface formation, and at least one characteristics of the manner in which the hydraulic fracture was created comprises the perforation design within which the hydraulic fracture was created. 
     
     
         10 . The method of  claim 1  wherein the at least one of a lithological description or localized stress of the subsurface formation, and at least one characteristics of the manner in which the hydraulic fracture was created comprises a combination of parameters for fracture treatment design. 
     
     
         11 . The method of  claim 1  wherein the at least one of a lithological description or localized stress of the subsurface formation, and at least one characteristics of the manner in which the hydraulic fracture was created comprises a combination of parameters for fracture treatment design such as Perforation location, Number of perforations, Size of perforations, Depth of Perforations, Viscosity of Fluid, Rate of Fluid, Temperature of Fluid, Amount of Proppant, Density of Proppant, Injection Density of Proppant, Size of Proppant, Injection Rate of Fluid, Chemical content of pumped fluid, Rate of Change in the viscosity of fluid, Rate of Change in the change of velocity of fluid, co-injection of energized gases (nitrogen, CO2, Propane, Methane) in both liquid and gas phases, Injection of Petroleum distillates, or pH of injection fluid (Acid/Base).