Monitoring Acid Stimulation Using High Resolution Distributed Temperature Sensing

Abstract

A method, apparatus and computer-readable medium for stimulating a formation is disclosed. A stimulation operation is performed at a selected stimulation zone of the formation using a first value of stimulation parameter. A temperature measurement profile is obtained at the formation during the stimulation operation, wherein the obtained temperature measurement profile is indicative of a parameter related to the stimulation operation. The downhole parameter is determined using the obtained temperature measurements, and stimulation parameter is altered to a second value in real-time based on the determined parameter.

What is claimed is: 
     
         1 . A method of stimulating a formation, comprising:
 performing a stimulation operation at a selected stimulation zone of the formation using a first value of stimulation parameter;   obtaining a temperature measurement profile at the formation during the stimulation operation, wherein the obtained temperature measurement profile is indicative of a parameter related to the stimulation operation;   determining the downhole parameter using the obtained temperature measurement profile; and   altering the stimulation parameter to a second value in real-time based on the determined parameter.   
     
     
         2 . The method of  claim 1  further comprising obtaining temperature data using a distributed temperature sensing system. 
     
     
         3 . The method of  claim 3 , further comprising performing a numerical decomposition of the obtained temperature data within a dynamic window in measurement space of the raw temperature data to obtain decomposition terms of first order and higher; applying an adaptive filter to the dynamic window to reduce noise from the decomposition terms of first order and higher; and obtaining the temperature profile using the filtered decomposition terms of first order and higher. 
     
     
         4 . The method of  claim 1 , wherein the temperature profile displays at least one of a temperature divergence and a temperature gradient in the formation. 
     
     
         5 . The method of  claim 1 , wherein altering the value of the stimulation parameter in real-time further comprises altering the parameter before an end of the stimulation operation. 
     
     
         6 . The method of  claim 1 , wherein the downhole parameter is at least one: (i) a zone cross-over; (ii) a zone permeability; (iii) a zone formation pressure; (iv) a placement of a diverting agent (v) an effectiveness of a diverting agent; (vi) an acid distribution profile; and (vii) a property of the formation that affects the stimulation operation. 
     
     
         7 . The method of  claim 1 , wherein obtaining the temperature measurement profile further comprises obtaining a spatio-temporal temperature measurement profile over a selected depth interval of the formation and over a selected time interval. 
     
     
         8 . A system for stimulating a formation, comprising:
 a workstring in a well formed in the formation;   a stimulation sub of the work string at a selected zone of the formation configured to perform a stimulation operation;   a temperature measurement system disposed along the workstring; and   a processor configured to:
 control the stimulation sub to perform the stimulation operation using a first value of a stimulation parameter, 
 obtain a temperature measurement profile during the stimulation operation from the distributed temperature sensing system, 
 determine a downhole parameter related to the of the stimulation operation from the obtained temperature measurement profile, and 
 alter the stimulation parameter to a second value in real-time based on the determined downhole parameter. 
   
     
     
         9 . The system of  claim 8 , wherein the temperature measurement system further comprises a distributed temperature sensing system configured to obtain temperatures measurements. 
     
     
         10 . The system of  claim 9 , wherein the processor is further configured to perform a numerical decomposition of the obtained temperature data within a dynamic window in measurement space of the raw temperature data to obtain decomposition terms of first order and higher, apply an adaptive filter to the dynamic window to reduce noise from the decomposition terms of first order and higher, and obtain the temperature profile using the filtered decomposition terms of first order and higher. 
     
     
         11 . The system of  claim 9 , wherein the processor is further configured to use the obtained temperature measurement profile to determine at least one of a temperature divergence and a temperature gradient in the formation. 
     
     
         12 . The system of  claim 8 , wherein the processor is further configured to alter the value of the stimulation parameter in real-time by altering the value of the stimulation parameter before a predetermined end of the stimulation operation. 
     
     
         13 . The system of  claim 8 , wherein the downhole parameter is at least one: (i) a zone cross-over; (ii) a zone permeability; (iii) a zone formation pressure; (iv) a placement of a diverting agent; (v) an effectiveness of a diverting agent; (vi) an acid distribution profile; and (vii) a property of the formation that affects the stimulation operation. 
     
     
         14 . The system of  claim 8 , wherein the temperature measurement profile further comprises a spatio-temporal temperature measurement profile over a selected depth interval of the formation and over a selected time interval. 
     
     
         15 . A computer-readable medium having stored thereon a set of instructions that when read by a processor enable the processor to perform a method for stimulating a formation, the method comprising:
 performing a stimulation operation using a first value of a stimulation parameter;   obtaining a temperature measurement profile related to the stimulation operation during the stimulation operation;   determining a downhole parameter related to the of the stimulation operation from the obtained temperature measurement profile; and   altering the stimulation parameter to a second value in real-time based on the determined downhole parameter.   
     
     
         16 . The computer-readable medium of  claim 15 , the method further comprising obtaining temperature data using a distributed temperature sensing system at the formation. 
     
     
         17 . The computer-readable medium of  claim 16 , the method further comprising performing a numerical decomposition of the obtained temperature data within a dynamic window in measurement space of the raw temperature data to obtain decomposition terms of first order and higher; applying an adaptive filter to the dynamic window to reduce noise from the decomposition terms of first order and higher; and obtaining the temperature profile using the filtered decomposition terms of first order and higher. 
     
     
         18 . The computer-readable medium of  claim 16 , the method further comprising using the obtained temperature measurement profile to determine at least one of a temperature divergence and a temperature gradient in the formation. 
     
     
         19 . The computer-readable medium of  claim 15 , wherein altering the stimulation parameter in real-time further comprises altering the parameter before a predetermined end of the stimulation operation. 
     
     
         20 . The computer-readable medium of  claim 15 , wherein the downhole parameter is at least one: (i) a zone cross-over; (ii) a zone permeability; (iii) a zone formation pressure; (iv) a placement of a diverting agent; (v) an effectiveness of a diverting agent; (vi) an acid distribution profile; and (vii) a property of the formation that affects the stimulation operation.