Packer set monitoring and compensating system and method

Abstract

A packer set monitoring and compensation system and method according to which the compression of the packer is sensed and a corresponding output signal is generated. The compression of the packer is changed in response to the sensed compression deviating from a predetermined value.

What is claimed is:  
     
         1 . A system for controlling the compression of a packer disposed in a well, comprising: 
 a sensor disposed in the well for sensing the compression of the packer and generating a corresponding output signal; and    an apparatus responsive to the output signal for changing the compression of the packer in response to the sensed compression deviating from a predetermined value.    
     
     
         2 . The system of  claim 1  wherein the sensor senses any decrease in the compression of the packer below a predetermined value, and in response the apparatus increases the compression of the packer to raise it back to the predetermined value.  
     
     
         3 . The system of  claim 1  further comprising a controller for receiving the output signal from the sensor, processing the signal, and providing an output signal corresponding to the compression of the packer, wherein the apparatus is responsive to the output signal provided by the controller.  
     
     
         4 . The system of  claim 1  wherein the sensor is a strain gauge.  
     
     
         5 . The system of  claim 1  wherein the sensor is a pressure sensor.  
     
     
         6 . The system of  claim 1  wherein the sensor is located on, or embedded in, the packer.  
     
     
         7 . The system of  claim 1  wherein the packer comprises: 
 a packer element; and  
 a shoe engaging the packer element;  
 wherein the sensor is mounted on the packer element and is located between the packer element and the shoe.  
 
     
     
         8 . The system of  claim 1  wherein the packer comprises a packer element, and the sensor is embedded in the packer element.  
     
     
         9 . The system of  claim 1  wherein the packer has a cavity for receiving fluid, and the apparatus comprises a valve responsive to the output signal for controlling the flow of fluid to the cavity to change the compression of the packer.  
     
     
         10 . The system of  claim 9  wherein the apparatus further comprises a compressor for compressing the fluid before it flows to the cavity.  
     
     
         11 . The system of  claim 9  wherein the packer comprises a packer element, and the cavity is formed in the packer element.  
     
     
         12 . The system of  claim 9  wherein the output signal is generated in response to the compression of the packer falling below a predetermined value, and the apparatus increases the pressure in the cavity to restore the compression.  
     
     
         13 . The system of  claim 1  wherein the sensor comprises: 
 a hydraulic cylinder; and  
 a piston moveable in the hydraulic cylinder in response to the deviation in compression of the packer.  
 
     
     
         14 . The system of  claim 13  wherein the sensor further comprises a rod extending from the piston and engaging the packer so that changes in the compression of the packer causes movement of the rod and therefore the piston.  
     
     
         15 . The system of  claim 14  wherein movement of the piston causes changes in fluid pressure in the hydraulic cylinder, and the sensor further comprises a fluid pressure sensor responsive to the pressure in the hydraulic cylinder for generating the output signal.  
     
     
         16 . The system of  claim 14  wherein the apparatus comprises: 
 a source of fluid; and  
 a pump responsive to the output signal for controlling the flow of fluid to the hydraulic cylinder to control the movement of the piston and therefore the compression of the packer.  
 
     
     
         17 . The system of  claim 16  further comprising a motor for driving the pump, wherein the motor is responsive to the output signal for driving the pump.  
     
     
         18 . A method for controlling the compression of a packer disposed in a well, comprising the steps of: 
 sensing the compression of the packer;    generating a corresponding output signal; and    changing the compression of the packer in response to the sensed compression deviating from a predetermined value.    
     
     
         19 . The method of  claim 18  wherein the step of changing comprises the step of increasing the compression of the packer to raise it back to the predetermined value.  
     
     
         20 . The method of  claim 18  further comprising the steps of: 
 receiving the output signal from the sensor;  
 processing the output signal from the sensor; and  
 providing a processed output signal corresponding to the compression of the packer;  
 wherein the step of changing is in response to the processed output signal.  
 
     
     
         21 . The method of  claim 18  wherein the step of sensing comprises the step of sensing the compressive strain on the packer.  
     
     
         22 . The method of  claim 18  wherein the step of sensing comprises the step of sensing the pressure on the packer.  
     
     
         23 . The method of  claim 18  wherein the step of sensing is done by a sensor mounted on, or embedded in, the packer.  
     
     
         24 . The method of  claim 18  further comprising the step of forming a cavity in the packer for receiving fluid, wherein the step of changing comprises the step of controlling the flow of fluid to the cavity for increasing the pressure of the packer.  
     
     
         25 . The method of  claim 24  wherein the step of changing further comprises the step of compressing the fluid before it flows to the cavity.  
     
     
         26 . The method of  claim 18  wherein the step of sensing comprises the step of providing a piston moveable in a hydraulic cylinder in response to the deviation in compression of the packer.  
     
     
         27 . The method of  claim 26  wherein movement of the piston causes changes in fluid pressure in the hydraulic cylinder, and the step of sensing further comprises the step of sensing the fluid pressure in the hydraulic cylinder.  
     
     
         28 . The method of  claim 26  wherein the step of changing comprises the step of pumping fluid into the hydraulic cylinder to control the movement of the piston and therefore the compression of the packer.  
     
     
         29 . A system for controlling the compression of a packer disposed in a well, comprising: 
 means disposed in the well for sensing the compression of the packer and generating a corresponding output signal; and    means responsive to the output signal for changing the compression of the packer in response to the sensed compression deviating from a predetermined value.