Hydraulic jet well cleaning method and apparatus

Abstract

A jet carrier assembly for cleaning well liners has a jet tool stabilized by a centralizer proximate to each of the tool's upper and lower ends. The jet tool is an elongate member having about 4 to 8 pairs of jet nozzles axially spaced therebetween, the axial spacing between alternate pairs being equal. The jet nozzles are spaced to provide a jet fluid track that covers any given point on the liner at least once but not more than twice when the member is lifted at a constant selected vertical speed and a constant selected rotational speed. The nozzles are mounted within adapters which are in turn detachably mounted to the elongate member. The adapters, which are provided in various sizes depending upon the diameter of the well liner, are interchangeable. The centralizers are capable of axial and rotational movement along mandrels attached to the upper and lower ends of the tool. The centralizers which are provided in varying sizes, depending upon well liner diameter, have a central bore which slidably engages the mandrel permitting the rotation of the centralizer to be isolated from the rotation of the jet tool. For any given diameter well liner, the adapters and centralizers are chosen to provide a jet nozzle to liner standoff distance of about 5 to 10 times the diameter of the nozzle orifice.

What is claimed: 
     
       1. A device for washing well liners comprising: an elongate member having jet nozzles spaced along its length;   tubing connected to .[.each.]. .Iadd.one .Iaddend.end of said member;   a centralizer located proximate to one end of said member, said centralizer being rigid and having a central bore for slidably engaging said tubing to permit substantial axial movement along said tubing; and   means to confine said axial movement of said centralizer, said axial movement being sufficient to permit reciprocation of said tubing with respect to said centralizer, said reciprocation providing a jarring action to help free said centralizer when jammed within said liner.   
     
     
       2. A method for washing well liners comprising: providing an elongate member having a plurality of jet nozzles spaced along its length, said member being of a standard size;   providing a plurality of sizes of adapters for receiving said nozzles on said member;   determining the size of said well liner; and   selecting an adapter sized to provide a jet nozzle to liner standoff distance of about 5-10 times the diameter of the nozzle orifice.   
     
     
       3. The method of claim 2 further comprising: providing a plurality of sizes of centralizers adapted to slidably engage tubing adjacent said member; and   selecting a centralizer sized to insure concentric rotation of the member and to prevent the jet nozzles from contacting the liner.