Downhole oilfield erosion protection of a jet pump throat by operating the jet pump in cavitation mode

Abstract

A method of improving erosion performance (decreasing the erosion) of components—such as a throat, a nozzle, or a diffuser—for a downhole tool used for cleaning a wellbore is disclosed.

1 . A method of protecting a jet pump throat from downhole erosion comprising the steps of: 
 positioning a jet pump in a wellbore, the jet pump comprising a nozzle and a throat;    pumping a power fluid through the jet pump at a sufficient velocity to cause the power fluid pressure in the area between the nozzle and throat to be less than or equal to the power fluid vapor pressure; and    drawing solids-ladened wellbore fluid into the jet pump and mixing the wellbore fluid with the power fluid.    
   
   
       2 . The method of claim I further comprising mixing the wellbore fluid and power fluid while the fluid pressure is less than or equal to the power fluid vapor pressure.  
   
   
       3 . The method of  claim 1  further comprising pumping the power fluid through the jet pump at a sufficient velocity to cause the power fluid pressure in the throat to be less than or equal to the power fluid vapor pressure.  
   
   
       4 . The method of  claim 1  further comprising transporting the mixture of power fluid and solids-ladened wellbore fluid through the throat of the jet pump and out of the wellbore.  
   
   
       5 . The method of  claim 1  whereby the jet pump is positioned in the wellbore by attaching the jet pump to a coil-in-coil tubing string and running the jet pump on the coil-in-coil tubing into the wellbore.  
   
   
       6 . The method of  claim 5  further comprising delivering the power fluid to the jet pump via the center tubing of a coil-in-coil tubing string.  
   
   
       7 . The method of  claim 5  further comprising returning the mixture of power fluid and solids-laden wellbore fluid to the surface via the coil tubing-coil tubing annulus.  
   
   
       8 . The method of  claim 1  wherein the power fluid pressure at the nozzle exit is about absolute zero.  
   
   
       9 . The method of  claim 1  wherein the power fluid is selected from brine, water, friction reduced water, gelled water, diesel, or hydraulic oil.  
   
   
       10 . A method of protecting a jet pump throat from downhole erosion comprising the steps of: 
 providing a jet pump in a wellbore, the jet pump comprising a nozzle, one or more well fluid inlet ports, and a throat; and    pumping a power fluid through the jet pump at a sufficient velocity to create cavitation vapor bubbles in the power fluid in the throat; and    drawing solids-ladened wellbore fluid through the well fluid inlet ports and mixing the wellbore fluid with the power fluid.    
   
   
       11 . The method of  claim 10  further comprising mixing the cavitation vapor bubbles in the power fluid with the wellbore fluid.  
   
   
       12 . The method of  claim 10  further comprising pumping the power fluid through the jet pump at a sufficient velocity to create cavitation vapor bubbles in the area between the nozzle and throat.  
   
   
       13 . The method of  claim 10  further comprising transporting the mixture of power fluid and solids-ladened wellbore fluid through the throat of the jet pump and out of the wellbore.  
   
   
       14 . The method of  claim 10  wherein the power fluid is selected from brine, water, friction reduced water, gelled water, diesel, or hydraulic oil.  
   
   
       15 . The method of  claim 10  further comprising attaching the jet pump to a coil-in-coil tubing string and positioning the jet pump at a desired location in the wellbore.  
   
   
       16 . The method of  claim 10  further comprising delivering the power fluid to the jet pump via the center tubing of a coil-in-coil tubing string.  
   
   
       17 . The method of  claim 16  further comprising pumping the fluid mixture to the surface via the coil tubing-coil tubing annulus.  
   
   
       18 . The method of  claim 10  wherein the power fluid pressure at the nozzle exit is about absolute zero.  
   
   
       19 . A method of protecting a jet pump throat from downhole erosion comprising the steps of: 
 positioning a jet pump in a wellbore, the jet pump comprising a nozzle and a throat;    pumping a power fluid through the jet pump at a sufficient velocity to cause the suction pressure in the area between the nozzle and throat to be less than or equal to the power fluid vapor pressure;    drawing solids-ladened wellbore fluid into the jet pump and mixing the wellbore fluid with the power fluid; and    transporting the mixture of fluid out of the wellbore.    
   
   
       20 . A method of removing solids from a wellbore comprising the steps of: 
 positioning a jet pump in a wellbore, the jet pump comprising a nozzle, a fluid inlet port and a throat;    pumping a fluid through the jet pump at a sufficient velocity to cause the power fluid pressure in the area between the nozzle and throat to be less than or equal to the power fluid vapor pressure; and    drawing solids-ladened wellbore fluid into the jet pump through the fluid inlet port and mixing the wellbore fluid with the power fluid.    
   
   
       21 . The method of  claim 20  further comprising mixing the wellbore fluid and power fluid while the fluid pressure is less than or equal to the power fluid vapor pressure.  
   
   
       22 . The method of  claim 20  further comprising pumping the power fluid through the jet pump at a sufficient velocity to cause the power fluid pressure in the throat to be less than or equal to the power fluid vapor pressure.  
   
   
       23 . The method of  claim 20  further comprising transporting the mixture of power fluid and solids-ladened wellbore fluid through the throat of the jet pump and out of the wellbore.  
   
   
       24 . The method of  claim 20  whereby the jet pump is positioned in the wellbore by attaching the jet pump to a coil-in-coil tubing string and running the jet pump on the coil-in-coil tubing into the wellbore.  
   
   
       25 . The method of  claim 24  further comprising delivering the power fluid to the jet pump via the center tubing of a coil-in-coil tubing string.  
   
   
       26 . The method of  claim 25  further comprising pumping the fluid mixture to the surface in the coil tubing-coil tubing annulus.  
   
   
       27 . The method of  claim 20  where the jet pump is operated at a suction pressure of about absolute zero.  
   
   
       28 . A method of removing solids from a wellbore comprising the steps of: 
 providing a jet pump in a wellbore, the jet pump comprising a nozzle, one or more well fluid inlet ports, and a throat;    pumping a power fluid through the jet pump at a sufficient velocity to create cavitation vapor bubbles in the power fluid in the throat; and    drawing solids from the wellbore through the well fluid inlet ports and mixing the solids with the cavitation vapor bubbles of the power fluid.    
   
   
       29 . The method of  claim 28  further comprising mixing the cavitation vapor bubbles in the power fluid with the solids.  
   
   
       30 . The method of  claim 28  further comprising transporting the mixture of power fluid and solids through the throat of the jet pump and out of the wellbore.  
   
   
       31 . The method of  claim 28  further comprising attaching the jet pump to a coil-in-coil tubing string and positioning the jet pump at a desired location in the wellbore.  
   
   
       32 . The method of  claim 31  further comprising delivering the power fluid to the jet pump via the center tubing of a coil-in-coil tubing string.  
   
   
       33 . The method of  claim 32  further comprising transporting the solids to the surface in the coil tubing-coil tubing annulus.  
   
   
       34 . The method of  claim 28  wherein the power fluid pressure at the nozzle exit is about absolute zero.  
   
   
       35 . A method of removing solids from a wellbore comprising the steps of: 
 pumping a power fluid to a downhole jet pump;    drawing wellbore solids into the jet pump and mixing the solids with the power fluid while the fluid pressure of the power fluid is less than or equal to the vapor pressure of the power fluid, and    transporting the solids-ladened mixture through the throat of the jet pump and out of the wellbore.    
   
   
       36 . The method of  claim 35  whereby the jet pump is positioned in the wellbore by attaching the jet pump to a coil-in-coil tubing string and running the jet pump on the coil-in-coil tubing into the wellbore.  
   
   
       37 . The method of  claim 36  further comprising delivering the power fluid to the jet pump via the center tubing of a coil-in-coil tubing string.  
   
   
       38 . The method of  claim 36  further comprising returning the mixture of power fluid and solids to the surface via the coil tubing-coil tubing annulus.  
   
   
       39 . The method of  claim 35  wherein the power fluid pressure at the nozzle exit is about absolute zero.  
   
   
       40 . The method of  claim 35  wherein the power fluid is selected from brine, water, friction reduced water, gelled water, diesel, or hydraulic oil.