Sand control screen having a micro-perforated filtration layer

Abstract

A sand control screen ( 40 ) includes a perforated base pipe ( 42 ) and a filter layer ( 50 ) that has micro-perforations ( 52 ) therein. The filter layer ( 50 ) is attached to the base pipe ( 42 ) along the entire length of the filter layer ( 50 ). Channels ( 46 ) are formed between the base pipe ( 42 ) and the filter layer ( 50 ) to allow fluid to flow therebetween. The sand control screen ( 40 ) is formed by micro-perforating a length of material, such as sheet metal, to form the filter layer ( 50 ), creating channels ( 46 ) that will allow fluids to flow between the base pipe ( 42 ) and filter layer ( 50 ), wrapping the filter layer ( 50 ) around the base pipe ( 42 ), attaching the filter layer ( 50 ) to the base pipe ( 42 ) along the length of the filter layer ( 50 ) and creating a seam between the two edges of the filter layer ( 50 ).

1 . A sand control screen comprising:
 a base pipe having at least one opening that allows fluid flow therethrough;   a filter layer attached to the base pipe, the filter layer having a plurality of micro-perforations; and   a drainage layer formed between the base pipe and the filter layer to allow fluid flow between the base pipe and the filter layer.   
   
   
       2 . The sand control screen as recited in  claim 1  wherein the filter layer has a thickness between about 1/32nd of an inch and about ¼th of an inch. 
   
   
       3 . The sand control screen as recited in  claim 1  wherein the filter layer is a sheet metal filter layer. 
   
   
       4 . The sand control screen as recited in  claim 1  wherein the shape of the micro-perforations at the surface of the filter layer is chosen from the group consisting of a circle, an ellipse and a slot. 
   
   
       5 . The sand control screen as recited in  claim 1  wherein the shape of the micro-perforations at the surface of the filter layer is chosen from the group consisting of a square, a triangle and a multi-sided polygon. 
   
   
       6 . The sand control screen as recited in  claim 1  wherein the micro-perforations have a maximum width of 500 microns. 
   
   
       7 . The sand control screen as recited in  claim 1  wherein the micro-perforations have a tapering cross-section through the filter layer. 
   
   
       8 . The sand control screen as recited in  claim 1  wherein the filter layer is attached to the base pipe by one of adhesion, a friction fit and fusion bonding. 
   
   
       9 . The sand control screen as recited in  claim 1  wherein the drainage layer further comprises channels. 
   
   
       10 . The sand control screen as recited in  claim 9  wherein the channels are formed in one of the outside surface of the base pipe and the inside surface of the filter layer. 
   
   
       11 . The sand control screen as recited in  claim 1  wherein the drainage layer further comprises one of wire wrap and wire mesh. 
   
   
       12 . A sand control screen comprising:
 a base pipe having at least one opening that allows fluid flow therethrough;   a sheet metal filter layer wrapped around the base pipe, the filter layer having a plurality of micro-perforations, the filter layer being corrugated to form channels between the filter layer and the base pipe; and   at least one connector coupling the filter layer to the base pipe.   
   
   
       13 . The sand control screen as recited in  claim 12  wherein the filter layer has a thickness between about 1/32nd of an inch and about ¼th of an inch. 
   
   
       14 . The sand control screen as recited in  claim 12  wherein the shape of the micro-perforations at the surface of the filter layer is chosen from the group consisting of a circle, an ellipse and a slot. 
   
   
       15 . The sand control screen as recited in  claim 12  wherein the shape of the micro-perforations at the surface of the filter layer is chosen from the group consisting of a square, a triangle and a multi-sided polygon. 
   
   
       16 . The sand control screen as recited in  claim 12  wherein the micro-perforations have a maximum width of 500 microns. 
   
   
       17 . The sand control screen as recited in  claim 12  wherein the micro-perforations are placed at the peaks and valleys of the corrugations. 
   
   
       18 . The sand control screen as recited in  claim 12  wherein the micro-perforations are spaced uniformly across the filter layer. 
   
   
       19 . A method of making a sand control screen, the method comprising:
 fabricating a plurality of openings in the wall of a base pipe, the plurality of openings allowing fluid flow therethrough;   creating a plurality of micro-perforations in a length of sheet metal having a first and a second edge opposite each other to form a filter layer;   forming a plurality of channels that allow fluid flow between the filter layer and the base pipe;   shaping the filter layer to fit around the base pipe wherein the first edge and the second edge of the filter layer are substantially adjacent each other;   attaching the filter layer to the outer surface of the base pipe; and   sealing the first edge of the filter layer to the second edge.   
   
   
       20 . The method of making a sand control screen as recited in  claim 19 , wherein the filter layer is corrugated prior to the shaping step. 
   
   
       21 . The method of making a sand control screen as recited in  claim 19 , wherein the shaping step and the attaching step are performed at the location where the sand screen is used. 
   
   
       22 . The method of making a sand control screen as recited in  claim 19 , wherein the attaching step uses an attachment method chosen from the group of fusion bonding, friction fitting and adhesion. 
   
   
       23 . The method of making a sand control screen as recited in  claim 19 , wherein the creating step creates micro-perforations having a tapering cross-section. 
   
   
       24 . The method of making a sand control screen as recited in  claim 23 , wherein the shaping step orients a smaller opening of the tapering cross-section on the exterior of the filter layer. 
   
   
       25 . The method of making a sand control screen as recited in  claim 19 , wherein the creating step uses one of a water jet and a laser to create the micro-perforations.