Unconventional Gas Fracture Logging Method and Apparatus

Abstract

A method for logging slick water hydraulic frac well includes the steps of: Perforating the well bore; Pumping fresh water into the reservoir; Running a high resistivity measurement tool down the hole to measure the resistance of the reservoir at selected intervals along the hole; Logging the resistance measurements; and Comparing the resistance of the reservoir strata with the resistance of the fresh water pumped into the reservoir to map the fracture. It is desirable but not necessary to run a high resistivity tool down the hole prior to the perforation step and measure the resistance of the reservoir to provide base line logging data, whereby the base line logging data may be compared with the water frac logging resistance measurements.

1 . A method for logging slick water hydraulic frac well comprising the steps of:
 a. Perforating the well bore;   b. Pumping fresh water into the reservoir;   c. Running a high resistivity measurement tool down the hole to measure the resistance of the reservoir at selected intervals along the hole;   d. Logging the resistance measurements;   e. Comparing the resistance of the reservoir strata with the resistance of the fresh water pumped into the reservoir to map the fracture.   
     
     
         2 . The method of  claim 1 , including the additional step of running a high resistivity tool down the hole prior to the perforation step and measuring the resistance of the reservoir to provide base line logging data. 
     
     
         3 . The method of  claim 2 , wherein the base line logging data is compared with the logging resistance measurements of step e. 
     
     
         4 . The method of  claim 1  wherein the high resistivity tool is a cased hole formation resistivity tool. 
     
     
         5 . The method of  claim 1 , wherein the hole is a cased hole. 
     
     
         6 . The method of  claim 1 , wherein the resistivity of the fresh water is measured prior to pumping it into the hole. 
     
     
         7 . The method of  claim 1 , wherein the fresh water contains a proppant.