Well screen apparatus and method of manufacture

Abstract

Disclosed is a well screen assembled on a base pipe and having an improved drainage layer disposed between the outer filter material and the base pipe. The improved drainage layer can be formed from a variety of materials and shapes. The drainage layer can be manufactured separately from the base pipe in the form of a tube severed along its length and subsequently assembled on the base pipe.

1 . A well screen comprising:
 a first tubular member having a longitudinal axis and an exterior surface;   a filter surrounding the exterior surface of the tubular member and forming an annular space between the filter and tubular member; and   a second tubular member positioned in the annular space formed between the filter and first tubular member; the second tubular member having a wall with a cut therethrough extending substantially from one end of the second tubular member to the other end thereof, and wherein the second tubular member provides fluid flow paths permitting flow in a longitudinal direction along the first tubular member.   
   
   
       2 . The well screen of  claim 1 , wherein the second tubular member comprises a wire-wrapped structure having a plurality of longitudinally extending rods arranged parallel to the outer surface of the first tubular member and having wire wrapped around the rods. 
   
   
       3 . The well screen of  claim 2 , wherein the wall of the wire-wrapped structure additionally comprises an outer diameter larger than the internal diameter of the filter, and, after cutting, is positioned in the annular space by radially compressing the wire-wrapped structure before inserting the screen inside the filter. 
   
   
       4 . The well screen of  claim 2 , wherein the wall of the wire-wrapped structure additionally comprises an inner diameter less than the outside diameter of the first tubular member, and, after cutting, the wire-wrapped structure is slid onto the first tubular member. 
   
   
       5 . The well screen of  claim 1 , wherein the second tubular member comprises a wall made from sheet material. 
   
   
       6 . The well screen of  claim 5 , wherein the sheet material additionally comprises deformations forming flow paths in the annular space. 
   
   
       7 . The well screen of  claim 6  wherein the sheet material additionally comprises openings in the wall of the sheet material. 
   
   
       8 . The well screen of  claim 1 , wherein the second tubular member additionally comprises a wall formed from a plurality of layers of mesh filter material. 
   
   
       9 . The well screen of  claim 1  wherein the second tubular member additionally comprises a wall formed from a plurality of channel-shaped members, the channel-shaped members extending in a longitudinal direction along the surface of the first tubular member. 
   
   
       10 . The well screen of  claim 9  wherein the channel members additionally comprise perforations in the wall of the channel members. 
   
   
       11 . The well screen of  claim 1  wherein the second tubular member has a wall formed from a plurality of tubular members, the tubular members extending in a longitudinal direction along the surface of the first tubular member. 
   
   
       12 . The well screen of  claim 10  wherein the tubular members additionally comprise perforations in the walls of the tubular members. 
   
   
       13 . The well screen of  claim 1  wherein the second tubular member comprises particulate material. 
   
   
       14 . The well screen of  claim 13 , wherein particulate material is selected from the group consisting of proppants and gravel pack materials. 
   
   
       15 . The well screen of  claim 1  wherein the second tubular member additionally comprises a wall formed from ceramic filter material. 
   
   
       16 . The well screen of  claim 15  wherein the ceramic filter material additionally comprises a wall with a 50% porosity. 
   
   
       17 . The well screen of  claim 1  wherein the first tubular member and the second tubular member being positioned juxtaposed by an interference fit between the two structures. 
   
   
       18 . A well screen comprising:
 a base pipe having a longitudinal axis and an exterior surface and at least one perforation in the wall of the base pipe;   a filter surrounding the exterior surface of the base pipe and forming an annular space between the filter and the base pipe; and   a generally tubular drainage layer member positioned in the annular space formed between the filter and the base pipe; the wall of the drainage layer comprising sheet material.   
   
   
       19 . The well screen of  claim 18  wherein the sheet material additionally comprises deformations in the sheet material to form flow paths in the annular space. 
   
   
       20 . The well screen of  claim 19  wherein the sheet material additionally comprises perforations in the sheet material. 
   
   
       21 . A well screen comprising:
 a base pipe having a longitudinal axis and an exterior surface and at least one perforation in the wall of the base pipe;   a filter surrounding the exterior surface of the base pipe and forming an annular space between the filter and base pipe; and   a generally tubular drainage layer member positioned in the annular space formed between the filter and the base pipe; the wall of the drainage layer formed from a plurality of channel-shaped members, the channel-shaped members extending in a longitudinal direction along the surface of the first tubular member.   
   
   
       22 . The well screen of  claim 21  wherein the channel members additionally comprise perforations in the channel members. 
   
   
       23 . A well screen comprising:
 a base pipe having a longitudinal axis and an exterior surface and at least one perforation in the wall of the base pipe;   a filter surrounding the exterior surface of the base pipe and forming an annular space between the filter and tubular member; and   a generally tubular drainage layer member positioned in the annular space formed between the filter and the base pipe; the wall of the drainage layer comprising a plurality of tubular members, the tubular members extending in a longitudinal direction along the surface of the first tubular member.   
   
   
       24 . The well screen of  claim 10  wherein the tubular members additionally comprise walls that are perforated. 
   
   
       25 . A well screen comprising:
 a base pipe having a longitudinal axis and an exterior surface and at least one perforation in the wall of the base pipe;   a filter surrounding the exterior surface of the base pipe and forming an annular space between the filter and tubular member; and   a generally tubular drainage layer member positioned in the annular space formed between the filter and base pipe; the drainage layer comprising particulate material.   
   
   
       26 . A well screen comprising:
 a base pipe having a longitudinal axis and an exterior surface and at least one perforation in the wall of the base pipe;   a filter surrounding the exterior surface of the base pipe and forming an annular space between the filter and tubular member; and   a generally tubular drainage layer member positioned in the annular space formed between the filter and the base pipe; the wall of the drainage layer comprising ceramic filter material.   
   
   
       27 . The well screen of  claim 26  wherein the ceramic filter material comprises material with a 50% porosity. 
   
   
       28 . A screen for placement at a subterranean location in a wellbore for removing solids from fluids entering the wellbore, the screen comprising:
 a unitary base pipe having an internal passageway, a longitudinal axis and an exterior surface and at least one flow path through the wall of the base pipe providing fluid communication between the exterior of the base pipe and internal passageway of the base pipe;   a plurality of axially-spaced annular filters surrounding the exterior surface of the base pipe, each of the filters located in the path of fluid flow between the wellbore and the interior passageway of the base pipe and each filter forming an annular space between the interior of the filter and the exterior of the base pipe;   drainage layer members positioned in each of the annular spaces formed between each filter and the base pipe; each drainage layer providing fluid flow paths permitting flow in a longitudinal direction along the exterior surface of the base pipe, the wall of each of the drainage layers comprising a wire-wrapped structure having a plurality of longitudinally extending rods arranged parallel to the outer surface of the first tubular member and wire wrapped around the rods, and   an annular structure on the base pipe having at least one passageway providing fluid communication between each drainage layer and at least one flow path through the wall of the base pipe whereby fluid flowing through the filter from the wellbore flows through the drainage layer and at least one flow path through the wall of the base pipe and into the interior passageway in the base pipe.   
   
   
       29 . The well screen of  claim 28  wherein each of the drainage layer structures comprises a wall with a cut therethrough extending substantially from one end of the drainage layer structure to the other end thereof. 
   
   
       30 . The well screen of  claim 28 , wherein the wire-wrapped structure additionally comprises the wall of each of the wire-wrapped structures has an outer diameter larger than the internal diameter of the filter, and, after cutting, is positioned in the annular space by radially compressing the wire-wrapped structure before inserting the screen inside the filter. 
   
   
       31 . The well screen of  claim 28 , wherein the wire-wrapped structure additionally comprises the wall of each of the wire-wrapped structure has an inner diameter less than the outside diameter of the first tubular member, and, after cutting, the wire-wrapped structure is slid onto the first tubular member. 
   
   
       32 . The well screen of  claim 28  additionally comprising at least one flow control device located in the flow path of fluid flowing from the filter to the interior of the base pipe. 
   
   
       33 . The well screen of  claim 28  additionally comprising a plurality of parallel flow paths through the wall of the base pipe and fluid flow control devices located in at least two of the parallel flow paths. 
   
   
       34 . A downhole apparatus comprising:
 a single segment of perforated base pipe;   a plurality of segments of filtering media arranged in a longitudinally spaced-apart relationship along the base pipe, and disposed externally to and in a spaced-apart relationship with the base pipe thereby defining an annular space betweeen the interior of each filtering media and the exterior of the base pipe; and,   a plurality of flow control devices disposed on the segment of base pipe and located in the spaces between the segments of filtering media.   
   
   
       35 . The apparatus of  claim 34  additionally comprising a drainage layer located in the annular space and permitting longitudinal fluid flow. 
   
   
       36 . The downhole apparatus of  claim 35 , wherein a cut extends substantially from one end of the drainage layer to the other end of the structure. 
   
   
       37 . The downhole apparatus of  claim 35  wherein the drainage member is a wire wrap screen. 
   
   
       38 . The downhole apparatus of  claim 37  wherein the wire wrap screen is rib based. 
   
   
       39 . A well screen comprising:
 a first tubular member;   a generally tubular shaped fluid filter having a longitudinally extending wall, the filter positioned with the first tubular member extending into the filter, the filter having a wall comprising a plurality of longitudinally extending rods and having wire connected to and wrapped around the rods; and a cut through the wall extending the longitudinal length of the filter.   
   
   
       40 . The apparatus of  claim 39  additionally comprising an annular space between the filter and the first tubular member and a drainage layer located in the annular space. 
   
   
       41 . The well screen of  claim 40  additionally comprising a drainage layer that permits longitudinal fluid flow. 
   
   
       42 . The well screen of  claim 40  wherein the drainage member comprises a second wire wrapped structure. 
   
   
       43 . The well screen of  claim 41  wherein the second wire wrap structure additionally comprises a plurality of longitudinally extending rods. 
   
   
       44 . The well screen of  claim 39  wherein the wire has a V shaped cross section. 
   
   
       45 . The well screen of  claim 39  wherein the wire has a trapezoidal cross section shape. 
   
   
       46 . The downhole apparatus of  claim 4  wherein the first tubular member has a wall with at least one opening therein for permitting fluid flow from the exterior to the interior thereof. 
   
   
       47 . A method of assembling a downhole apparatus comprising:
 selecting a segment of perforated base pipe;   selecting a plurality of segments of filtering media;   positioning the segments of filtering media in a longitudinally spaced-apart relationship along the segment of base pipe; and,   positioning a flow control device in one or more of the spaces between segments of filtering media.