Apparatus and method for clearing solids from a well

Abstract

An apparatus for clearing solids from a well including a housing with a jet pump, for positioning in a production string of the well, a tailpipe string carrying an elongate body to project out of a downhole end of the production string, a coupling to connect to inner tubing positioned within the production string for providing pressurised fluid to drive the jet pump, and a conduit which bypasses the jet pump in order to deliver pressurised fluid into the tailpipe string, wherein the tailpipe string includes a nozzle assembly to jet pressurised fluid into the well in order to agitate and stir up solids adjacent the elongate body and the elongate body includes an intake screen through which the solids are suctioned into an internal channel of the apparatus which is in fluid communication with an inlet of the jet pump, and wherein the jet pump has an exit for pumping the solids into a space between the apparatus and the production string in order to force the solids up-hole and out of the well. The invention also relates to a method of extracting solids from a well using the apparatus described above, including attaching the apparatus to an inner tubing which supplies power fluid to the apparatus, feeding the apparatus down the well and supplying the power fluid through the inner tubing to agitate solids in the well and suction the agitated solids into the apparatus and out of the jet pump exit to thereby force the solids up-hole for extraction from the well.

1 . An apparatus for clearing solids from a well including a housing with a jet pump, for positioning in a production string of the well, a tailpipe string carrying an elongate body to project out of a downhole end of the production string, a coupling to connect to inner tubing positioned within the production string for providing pressurised fluid to drive the jet pump, and a conduit which bypasses the jet pump in order to deliver pressurised fluid into the tailpipe string, wherein the tailpipe string includes a nozzle assembly to jet pressurised fluid into the well in order to agitate and stir up solids adjacent the elongate body and the elongate body includes an intake screen through which the solids are suctioned into an internal channel of the apparatus which is in fluid communication with an inlet of the jet pump, and wherein the jet pump has an exit for pumping the solids into a space between the apparatus and the production string in order to force the solids up-hole and out of the well. 
     
     
         2 . The apparatus of  claim 1 , wherein the nozzle assembly includes at least one nozzle at a nosing end of the tailpipe string. 
     
     
         3 . The apparatus of  claim 1 , wherein the nozzle assembly includes at least one nozzle at an up-hole location relative to the screen to maintain agitation of the solids before being suctioned through the intake screen. 
     
     
         4 . The apparatus of  claim 1 , further including a seal arrangement below the exit of the jet pump to seal against the production string and contain the agitated solids outside the elongate body to a downhole side of the jet pump, for extraction through the intake screen. 
     
     
         5 . The apparatus of  claim 1 , configured to be mounted to an existing seat in the production string and the tailpipe string has a reduced diameter to pass through the seat to exit the downhole end of the production string. 
     
     
         6 . The apparatus of  claim 1 , wherein the tailpipe string is dimensioned to pass through an opening from which a rotor of a PCP pump has been extracted. 
     
     
         7 . The apparatus of  claim 1 , wherein the tailpipe string is dimensioned to pass through the opening from which a rod pump has been extracted. 
     
     
         8 . The apparatus of  claim 1 , wherein the coupling includes a diverter to direct power fluid delivered through the inner tubing into both the conduit which extends into the tailpipe/tubing and the jet pump. 
     
     
         9 . A method of extracting solids from a well using the apparatus of  claim 1 , including attaching the apparatus to an inner tubing which supplies power fluid to the apparatus, feeding the apparatus down the well and supplying the power fluid through the inner tubing to agitate solids in the well and suction the agitated solids into the apparatus and out of the jet pump exit to thereby force the solids up-hole for extraction from the well. 
     
     
         10 . The method of  claim 9 , further including jetting pressurised fluid through nozzles positioned above and below the screen to maintain a dilute slurry of agitated solids adjacent the intake screen of the apparatus. 
     
     
         11 . The method of  claim 9 , further including jetting pressurised fluid through nozzles positioned above and below the screen to maintain a dilute slurry of agitated solids adjacent the intake screen of the apparatus and also reduce the particle size of particles in the slurry such that they are compatible with the screen intake. 
     
     
         12 . The method of  claim 11 , wherein the nozzles to jet the pressurised fluid are positioned such that the nozzles generate an intense turbulent cloud which acts to generally maintain an unblocked screen by ejecting blocked particles from the screen thereby permitting continuous operation. 
     
     
         13 . The method of  claim 9 , further including firstly removing a rotor and rotor string of a PCP pump from an opening in a stator of a production string and passing the apparatus through the stator such that the tailpipe string extends through the opening, downhole of the production string, toward a bottom of the well. 
     
     
         14 . The method of  claim 9 , further including firstly removing a rod pump and rod string of a rod pump from a seating nipple in a production string and passing the apparatus through the pump seating nipple such that the tailpipe string extends through a resultant opening, downhole of the production string toward a bottom of the well.