Vibrating system and method for use in scale removal and formation stimulation in oil and gas recovery operations

Abstract

A system and method for removing scale from a device for supporting a gravel pack in a wellbore and for stimulating a formation penetrated by the wellbore, according to which a transducer and a driver for the transducer are mounted on a tool which is lowered into the wellbore in the vicinity of the device. The driver is actuated to vibrate the transducer to remove the scale and stimulate the formation.

1 . A system for use in a wellbore, comprising: 
 a tool adapted to be inserted in the wellbore;    a driver mounted to the tool for supplying electrical power; and    a transducer mounted on the outside of the tool and adapted to vibrate in response to the electrical power supplied by the driver.    
   
   
       2 . The system of  claim 1  further comprising a screening device for supporting a gravel pack in the wellbore, wherein vibration of the transducer removes scale from the screening device.  
   
   
       3 . The system of  claim 1  wherein vibration of the transducer removes scale from the wall of the wellbore to stimulate a formation penetrated by the wellbore.  
   
   
       4 . The system of  claim 1  further comprising: 
 a sensor for sensing scale accumulation and outputting a signal when the scale accumulation exceeds a predetermined value; and    means responsive to the signal for actuating the driver.    
   
   
       5 . The system of  claim 4  wherein the sensor is mounted on the tool.  
   
   
       6 . The system of  claim 4  wherein the means comprises a microprocessor connected to the sensor and to the driver.  
   
   
       7 . The system of  claim 6  wherein the microprocessor is mounted on the tool.  
   
   
       8 . The system of  claim 1  wherein the transducer is selected from the group consisting of a tuning fork, a cantilever, an oval-mode tool, a magnetostrictive driver, and a piezoelectric transducer.  
   
   
       9 . A method of cleaning scale located in a wellbore, comprising the steps of: 
 providing a tool comprising: 
 a transducer mounted on the outside of the tool; and  
 a driver for the transducer;  
   lowering the tool into the wellbore in the vicinity of the scale; and    actuating the driver to vibrate the transducer to remove the scale.    
   
   
       10 . The method of  claim 9  wherein the scale is removed from a gravel support device in the wellbore.  
   
   
       11 . The method of  claim 9  wherein the scale is removed from the wall of the wellbore to stimulate a formation penetrated by the wellbore.  
   
   
       12 . The method of  claim 9  further comprising the steps of: 
 sensing scale accumulation;    outputting a signal when the scale accumulation exceeds a predetermined value; and    actuating the driver in response to the outputting of the signal.    
   
   
       13 . The method of  claim 12  wherein the step of sensing is done by a sensor mounted on the tool.  
   
   
       14 . The method of  claim 13  wherein the step of actuating comprises the step of connecting the sensor and the driver, to a control unit for actuating the driver when the signal is outputted from the sensor.  
   
   
       15 . The method of  claim 14  further comprising the step of mounting the control unit on the tool.  
   
   
       16 . A system for use in a wellbore, comprising: 
 a tool adapted to be inserted in the wellbore;    first means mounted to the tool for supplying electrical power; and    second means mounted on the outside of the tool for vibrating in response to the electrical power supplied by the first means.    
   
   
       17 . The system of  claim 16  further comprising means for supporting a gravel pack in the wellbore, wherein vibration of the second means removes scale from the means for supporting a gravel pack.  
   
   
       18 . The system of  claim 16  wherein vibration of the second means removes scale from wall of the wellbore to stimulate a formation penetrated by the wellbore.  
   
   
       19 . The system of  claim 16  further comprising: 
 means for sensing scale accumulation and outputting a signal when the scale accumulation exceeds a predetermined value; and    means responsive to the signal for actuating the first means.    
   
   
       20 . The system of  claim 19  wherein the means for sensing is mounted on the tool.  
   
   
       21 . The system of  claim 19  wherein the means for actuating comprises a microprocessor connected to the means for sensing and to the first means.  
   
   
       22 . The system of  claim 21  wherein the microprocessor is mounted on the tool.  
   
   
       23 . The system of  claim 16  wherein the second means is selected from the group consisting of a tuning fork, a cantilever, an oval-mode tool, a magnetostrictive driver, and a piezoelectric transducer.