Methods for monitoring well cementing operations

Abstract

Cement placement simulations and post-placement simulations are traditionally performed before the cementing operation takes place. Several simulation iterations may be performed, allowing engineers to develop an optimal cement treatment design. When the cementing operation takes place, engineers may follow the procedure prescribed by the simulator. After the operation is complete and the cement has set, logging operations may be performed to verify that the goals of the cementing operation have been met. Monitoring the progress of the cementing operation in real time allows a determination of whether cementing events are unfolding as predicted by the simulator. If deviations from the plan occur, some real-time adjustments may be made to improve cementing results.

1 . A method for cementing a subterranean well, comprising:
 (i) preparing a cement slurry;   (ii) pumping the slurry into the well through a casing interior and, after exiting the casing interior, through an annulus between a casing exterior and a borehole wall;   (iii) real-time monitoring of parameters comprising temperature, pressure or return rate or a combination thereof; and   (iv) comparing the real-time monitored parameters to a previously generated cement placement simulation or a previously generated post-cement placement simulation or both.   
     
     
         2 . The method of  claim 1 , wherein temperature sensors are located at a wellhead, at a casing shoe, along fibers installed throughout the well, or at a return line or a combination thereof. 
     
     
         3 . The method of  claim 1 , wherein pressure sensors are located at a wellhead, at a casing shoe, along fibers installed throughout the well, or at a return line or a combination thereof. 
     
     
         4 . The method of  claim 1 , wherein flow rate sensors are located at a wellhead, at a casing shoe, along fibers installed throughout the well, at a mud pit, or at a return line or a combination thereof. 
     
     
         5 . The method of  claim 1 , wherein the monitored parameters are synchronized and displayed together on a computer screen. 
     
     
         6 . The method of  claim 1 , wherein the post-placement simulation employs calorimetry data to provide a post-placement well temperature prediction. 
     
     
         7 . The method of  claim 1 , wherein the monitored parameters provide a real-time prediction of when the cement slurry will reach a given location in the well. 
     
     
         8 . A method for confirming cement-placement events, comprising:
 (i) preparing a cement slurry;   (ii) pumping the slurry into a well through a casing interior and, after exiting the casing interior, through an annulus between a casing exterior and a borehole wall;   (iii) real-time monitoring of parameters comprising temperature, pressure or return rate or a combination thereof; and   (iv) comparing the real-time monitored parameters to a previously generated cement placement simulation or a previously generated post-cement placement simulation or both.   
     
     
         9 . The method of  claim 8 , wherein temperature sensors are located at a wellhead, at a casing shoe, along fibers installed throughout the well, or at a return line or a combination thereof. 
     
     
         10 . The method of  claim 8 , wherein pressure sensors are located at a wellhead, at a casing shoe, along fibers installed throughout the well, or at a return line or a combination thereof. 
     
     
         11 . The method of  claim 8 , wherein flow rate sensors are located at a wellhead, at a casing shoe, along fibers installed throughout the well, at a mud pit, or at a return line or a combination thereof. 
     
     
         12 . The method of  claim 8 , wherein the monitored parameters are synchronized and displayed together on a computer screen. 
     
     
         13 . The method of  claim 8 , wherein the post-placement simulation employs calorimetry data to provide a post-placement well temperature prediction. 
     
     
         14 . The method of  claim 8 , wherein the cement-placement events comprise landing of a cementing plug, landing of a cementing dart, passage of a fluid interface past a given location in a well, setting of the cement slurry, or arrival of a cement slurry at a given location in the well, or combinations thereof. 
     
     
         15 . A method for modifying a cement placement simulation, comprising:
 (i) preparing a cement slurry;   (ii) pumping the slurry into a well through a casing interior and, after exiting the casing interior, through an annulus between a casing exterior and a borehole wall;   (iii) real-time monitoring of parameters comprising pump rate, pressure, fluid volume, fluid density or fluid temperature or combinations thereof;   (iv) entering real-time data into a cement placement simulator and allowing the simulator to predict future cement-placement events.   
     
     
         16 . The method of  claim 15 , wherein a cement placement simulation has been performed before pumping the slurry into the well. 
     
     
         17 . The method of  claim 15 , wherein a cement placement simulation has not been performed before pumping the slurry into the well, and future cement-placement events are predicted in real time. 
     
     
         18 . The method of  claim 15 , wherein temperature sensors are located at a wellhead, at a casing shoe, along fibers installed throughout the well, or at a return line or a combination thereof. 
     
     
         19 . The method of  claim 15 , wherein pressure sensors are located at a wellhead, at a casing shoe, along fibers installed throughout the well, or at a return line or a combination thereof. 
     
     
         20 . The method of  claim 15 , wherein flow rate sensors are located at a wellhead, at a casing shoe, along fibers installed throughout the well, at a mud pit, or at a return line or a combination thereof.