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 characterizing a hydraulic fracture in a subsurface formation, comprising:
 inducing a pressure change in a single well drilled through the subsurface formation, the inducing a pressure change inducing tube waves in the well;   measuring at a location proximate to a wellhead at least one of pressure and a time derivative of pressure in the single well for a selected length of time; and   determining at least one of a physical parameter and a change in the physical parameter with respect to time, of at least one fracture induced in a formation adjacent to the single well by pumping fluid into the formation through the well, using reflected tube wave components of the measured at least one of pressure and the time derivative of pressure.   
     
     
         2 . The method of  claim 1  wherein the inducing a pressure change comprises pumping a hydraulic fracture treatment. 
     
     
         3 . The method of  claim 1  wherein the inducing a pressure change comprises water hammer generated by changing a flow rate of fluid into or out of the single well. 
     
     
         4 . The method of  claim 1  wherein the inducing a pressure change comprises operating an acoustic source which propagates a positive and/or negative pressure pulse into fluid within the single well. 
     
     
         5 . The method of  claim 2  wherein the at least one of a physical parameter, and a change in the physical parameter with respect to time is determined before the pumping the hydraulic fracture treatment. 
     
     
         6 . The method of  claim 2  wherein the at least one of a physical parameter, and a change in the physical parameter with respect to time is determined during the pumping the hydraulic fracture treatment. 
     
     
         7 . The method of  claim 2  wherein the at least one of a physical parameter, and a change in the physical parameter with respect to time is determined after the pumping the hydraulic fracture treatment. 
     
     
         8 . The method of  claim 1  wherein the at least one of a physical parameter, and a change in the parameter with respect to time is the mathematical product of fracture permeability and fracture width divided by the viscosity of the fluid. 
     
     
         9 . The method of  claim 1  wherein the at least one of a physical parameter, and a change in the physical parameter with respect to time of at least one fracture is a number of fractures. 
     
     
         10 . The method of  claim 1  wherein the at least one of a physical parameter, and a change in the physical parameter with respect to time comprises fracture width. 
     
     
         11 . The method of  claim 1  wherein the at least one of a physical parameter, and a change in the physical parameter with respect to time comprises fracture height. 
     
     
         12 . The method of  claim 1  wherein the at least one of a physical parameter, and a change in the physical parameter with respect to time comprises fracture length. 
     
     
         13 . The method of  claim 1  wherein the at least one of a physical parameter, and a change in the physical parameter with respect to time comprises fluid conductivity of the at least one fracture. 
     
     
         14 . The method of  claim 1  wherein the at least one of a physical parameter, and a change in the physical parameter with respect to time comprises fluid connectivity to the single well. 
     
     
         15 . The method of  claim 1  wherein the at least one of a physical parameter, and a change in the physical parameter with respect to time comprises spatial variation of fracture conductivity. 
     
     
         16 . The method of  claim 1  wherein the at least one of a physical parameter and a change in the physical parameter with respect to time comprises proppant spatial distribution. 
     
     
         17 . The method of  claim 1  wherein the at least one of a physical parameter and a change in the physical parameter with respect to time comprises drainage volume. 
     
     
         18 . The method of  claim 1  wherein the at least one of a physical parameter, and a change in the physical parameter with respect to time comprises fracture complexity. 
     
     
         19 . The method of  claim 1  wherein the at least one physical parameter and a change in the physical parameter with respect to time is determined from at least one of reflection time, reflection phase and reflection amplitude. 
     
     
         20 . The method of  claim 1  wherein the at least one physical parameter and a change in the physical parameter with respect to time is determined from at least one of frequency, quality factor and amplitude of a resonance.