Method of treating a subterranean formation

Abstract

A method of treating a subterranean formation, involving performing a fracturing operation and performing a shut in. At a time before or after the shut in is commenced, changes in properties at or near a fracture are estimated based upon monitored data. A plugging agent is injected taking into consideration the estimated changes in properties.

What is claimed is: 
     
         1 . A method of treating a subterranean formation penetrated by a wellbore comprising:
 performing a fracturing operation by introducing a treatment fluid into the wellbore at a fluid pressure equal to or greater than a fracture initiation pressure of the subterranean formation to induce a fracture in the subterranean formation;   estimating changes in fracture geometry by monitoring data from one or more sensors while the fracture is open;   performing a shut-in by stopping injection of the treatment fluid; and   introducing a plugging agent, after performing the shut-in, plugging the induced fracture;   wherein the plugging agent is introduced after a period of time, the period of time being determined based upon the monitored data.   
     
     
         2 . The method according to  claim 1 , wherein the plugging agent is introduced into the wellbore after the shut-in is performed. 
     
     
         3 . The method according to  claim 1 , wherein the plugging agent is introduced into the wellbore before the shut-in is performed. 
     
     
         4 . The method according to  claim 1 , wherein the plugging agent includes a diverter pill. 
     
     
         5 . The method according to  claim 1 , wherein the period of time is from 5 minutes to 12 hours. 
     
     
         6 . The method according to  claim 1 , wherein the period of time is from 15 minutes to 2 hours. 
     
     
         7 . The method according to  claim 1 , wherein the estimating the changes in the fracture geometry occurs in real-time by monitoring real-time data. 
     
     
         8 . The method according to  claim 1 , wherein a width of the fracture is decreased to a value smaller than the size of the plugging agent. 
     
     
         9 . The method according to  claim 1 , further comprising generating tubewaves on surface, wherein the monitored data comprises data acquired while monitoring tubewave reflections from the fracture. 
     
     
         10 . The method according to  claim 9 , wherein the low-frequency pressure waves comprise one or more pulses. 
     
     
         11 . The method according to  claim 9 , wherein the plugging agent is introduced at a time when the change in values of the tubewave reflections reach a threshold amount. 
     
     
         12 . The method according to  claim 9 , further comprising resuming the introduction of the treatment fluid into the wellbore at a fluid pressure equal to or greater than the fracture initiation pressure of the subterranean formation. 
     
     
         13 . The method according to  claim 9 , wherein the monitoring data comprises monitoring a fluid pressure change in the wellbore after the shut-in is initiated. 
     
     
         14 . The method according to  claim 13 , wherein the fluid pressure change is determined by plotting a G function plot. 
     
     
         15 . The method according to  claim 13 , further comprising determining fluid leakoff based upon the monitored fluid pressure change in the wellbore. 
     
     
         16 . A method of monitoring a portion of a subterranean formation, comprising:
 performing a fracturing operation by introducing a treatment fluid into the wellbore at a fluid pressure equal to or greater than a fracture initiation pressure of the subterranean formation to induce a fracture in the subterranean formation;   generating tubewaves on surface, wherein the tubewaves comprise one or more pulses;   detecting a change in reflection of the pulses to thereby determine a characteristic of the fracture of the subterranean formation in real-time; and   introducing a plugging agent.   
     
     
         17 . The method according to  claim 16 , wherein the characteristic of the fracture of the subterranean formation includes whether a width of an opening of the fracture has decreased by a predetermined amount. 
     
     
         18 . The method according to  claim 16 , wherein the introducing further comprises introducing a plugging agent when the characteristic of the fracture of the subterranean formation has reached a threshold amount. 
     
     
         19 . The method according to  claim 18 , wherein the plugging agent is a diverter pill. 
     
     
         20 . A method of monitoring a portion of a subterranean formation, comprising:
 performing a fracturing operation by introducing a treatment fluid into the wellbore at a fluid pressure equal to or greater than a fracture initiation pressure of the subterranean formation to induce a fracture in the subterranean formation;   monitoring a fluid pressure change in the wellbore of the subterranean formation; and   treating the fracture in the subterranean formation at a time that is calculated based on when the fluid pressure change in the wellbore reaches a threshold value.   
     
     
         21 . The method according to  claim 20 , wherein the threshold value of the pressure change is a value calculated by plotting a G function plot and determining where a measured pressure deviates from linearity. 
     
     
         22 . The method according to  claim 20 , wherein treating the fracture includes introducing a plugging agent into an induced fracture. 
     
     
         23 . The method according to  claim 22 , wherein the plugging agent is pumped at a pressure lower than the fracture initiation pressure.