Expandable well screen

Abstract

An expandable well screen provides increased collapse, torsional and tensile strength. In a described embodiment, an expandable well screen includes a generally tubular base pipe and an external filtering media. The well screen is configured to have sufficient torsional and tensile strength for conveyance and positioning in a wellbore, while also having sufficient strength to prevent collapse when the screen is radially expanded.

What is claimed is:  
     
         1 . An expandable well screen, comprising: 
 a filtering media, the filtering media stretching circumferentially when the well screen is radially outwardly expanded.    
     
     
         2 . The well screen according to  claim 1 , wherein the filtering media comprises an elongated strip disposed in a helical configuration.  
     
     
         3 . The well screen according to  claim 1 , wherein the filtering media includes a layer of relatively fine filtering material sandwiched between layers of relatively coarse filtering material.  
     
     
         4 . The well screen according to  claim 3 , wherein the relatively fine filtering material is a sintered woven filtering material.  
     
     
         5 . The well screen according to  claim 1 , wherein the filtering media is generally tubular and has multiple slots formed therethrough.  
     
     
         6 . The well screen according to  claim 5 , wherein the slots are arranged helically relative to a longitudinal axis of the filtering media.  
     
     
         7 . The well screen according to  claim 1 , wherein the filtering media filters particles having a size of greater than 500 μm when the well screen is radially outwardly expanded.  
     
     
         8 . The well screen according to  claim 1 , wherein openings through the filtering media for fluid flow therethrough change size by less than fifty percent when the well screen is radially outwardly expanded.  
     
     
         9 . An expandable well screen, comprising: 
 a generally tubular base pipe having a longitudinal axis and a series of spaced apart rows of holes formed through a sidewall of the base pipe, the holes of each row interconnecting with each other when the base pipe is expanded radially outward; and    a filtering media configured for filtering fluid flowing through the base pipe holes.    
     
     
         10 . The expandable well screen according to  claim 9 , wherein the series of rows of holes is arranged helically on the base pipe relative to the longitudinal axis.  
     
     
         11 . The expandable well screen according to  claim 9 , wherein the holes in each row are distributed along a line.  
     
     
         12 . The expandable well screen according to  claim 9 , further comprising a generally tubular protective shroud outwardly overlying the filtering media.  
     
     
         13 . The expandable well screen according to  claim 12 , wherein the shroud includes a recess formed internally thereon, the recess permitting transverse fluid flow between the shroud and the filtering media when the filtering media is compressed against the shroud.  
     
     
         14 . The expandable well screen according to  claim 9 , wherein the filtering media includes a layer of relatively fine filtering material sandwiched between layers of relatively coarse filtering material.  
     
     
         15 . The expandable well screen according to  claim 14 , wherein the relatively fine filtering material is a sintered woven filtering material.  
     
     
         16 . The expandable well screen according to  claim 9 , wherein the filtering media includes a woven material having strands thereof which are arranged helically relative to the base pipe longitudinal axis.  
     
     
         17 . The expandable well screen according to  claim 9 , wherein the base pipe includes a recess externally formed thereon, the recess permitting transverse fluid flow between the base pipe and the filtering media when the filtering media is compressed against the base pipe.  
     
     
         18 . An expandable well screen, comprising: 
 a generally tubular base pipe having a longitudinal axis and a series of holes formed through a sidewall of the base pipe, the holes being distributed helically relative to the base pipe longitudinal axis, and each of the holes being compressed in a direction of the base pipe longitudinal axis when the base pipe is expanded radially outward; and    a filtering media disposed externally on the base pipe.    
     
     
         19 . The expandable well screen according to  claim 18 , further comprising a generally tubular protective shroud outwardly overlying the filtering media.  
     
     
         20 . The expandable well screen according to  claim 18 , wherein the filtering media includes a layer of relatively fine filtering material sandwiched between layers of relatively coarse filtering material.  
     
     
         21 . The expandable well screen according to  claim 20 , wherein the relatively fine filtering material is a sintered woven filtering material.  
     
     
         22 . The expandable well screen according to  claim 18 , wherein the filtering media includes a woven material having strands thereof which are arranged helically relative to the base pipe longitudinal axis.  
     
     
         23 . An expandable well screen, comprising: 
 an elongated strip of filtering media wrapped helically about a longitudinal axis.    
     
     
         24 . The expandable well screen according to  claim 23 , wherein the filtering media includes a woven material with strands thereof oriented helically relative to the longitudinal axis.  
     
     
         25 . The expandable well screen according to  claim 23 , wherein the filtering media is disposed in multiple wraps.  
     
     
         26 . The expandable well screen according to  claim 25 , wherein each wrap of the filtering media is attached to an adjacent wrap of the filtering media at a connection therebetween, the connection extending helically relative to the longitudinal axis.  
     
     
         27 . The expandable well screen according to  claim 26 , wherein the connection between the filtering media wraps comprises a welded seam between the wraps.  
     
     
         28 . The expandable well screen according to  claim 26 , wherein the connection between the filtering media wraps comprises a connector positioned between the filtering media wraps.  
     
     
         29 . The expandable well screen according to  claim 28 , further comprising a communication line positioned adjacent the connector and extending helically relative to the longitudinal axis.  
     
     
         30 . The expandable well screen according to  claim 28 , further comprising a power line positioned adjacent the connector and extending helically relative to the longitudinal axis.  
     
     
         31 . The well screen according to  claim 28 , further comprising a hydraulic line positioned adjacent the connector and extending helically relative to the longitudinal axis.  
     
     
         32 . The well screen according to  claim 23 , wherein the filtering media includes a layer of relatively fine filtering material sandwiched between layers of relatively coarse filtering material.  
     
     
         33 . The expandable well screen according to  claim 32 , wherein the relatively fine filtering material is a sintered woven filtering material.  
     
     
         34 . An expandable well screen, comprising: 
 multiple elongated strips of filtering media spaced apart and distributed circumferentially about a longitudinal axis and extending parallel to the longitudinal axis; and    multiple elongated expansion strips, one of the expansion strips being interconnected between each adjacent pair of the filtering media strips, and the expansion strips lengthening circumferentially to thereby increase circumferential separation between the filtering media strips.    
     
     
         35 . The expandable well screen according to  claim 34 , wherein the expansion strips have longitudinal corrugations formed thereon, and wherein the corrugations are at least partially straightened when the expansion strips lengthen circumferentially.  
     
     
         36 . The expandable well screen according to  claim 34 , wherein the filtering media includes a layer of relatively fine filtering material sandwiched between layers of relatively coarse filtering material.  
     
     
         37 . The expandable well screen according to  claim 36 , wherein the relatively fine filtering material is a sintered woven filtering material.  
     
     
         38 . The expandable well screen according to  claim 34 , further comprising multiple elongated protective shroud strips, one of the shroud strips outwardly overlying each of the filtering media strips.  
     
     
         39 . The expandable well screen according to  claim 38 , wherein each of the shroud strips is interconnected between two of the expansion strips.  
     
     
         40 . The expandable well screen according to  claim 34 , further comprising at least one retaining member securing at least one of the expansion strips in a compressed configuration thereof, the retaining member releasing the at least one expansion strip for expansion thereof when the expansion strips lengthen circumferentially.  
     
     
         41 . The expandable well screen according to  claim 40 , further comprising multiple elongated protective shroud strips, one of the shroud strips outwardly overlying each of the filtering media strips, and the retaining member being connected to two of the shroud strips.  
     
     
         42 . The expandable well screen according to  claim 40 , wherein the retaining member is connected across at least one of the expansion strips.  
     
     
         43 . The expandable well screen according to  claim 42 , wherein the retaining member is attached directly to the at least one expansion strip.  
     
     
         44 . The expandable well screen according to  claim 40 , wherein the retaining member extends externally across a longitudinally extending fold formed in a base pipe.  
     
     
         45 . The expandable well screen according to  claim 40 , wherein the retaining member extends externally across a longitudinally extending undulation in a base pipe.  
     
     
         46 . The expandable well screen according to  claim 34 , further comprising a base pipe deformed to a radially reduced configuration thereof.  
     
     
         47 . The expandable well screen according to  claim 46 , wherein the base pipe has an hourglass cross-sectional shape.  
     
     
         48 . An expandable well screen, comprising: 
 a generally tubular filtering media, the filtering media including expansion portions thereof permitting circumferential lengthening of the filtering media.    
     
     
         49 . The expandable well screen according to  claim 48 , wherein the filtering media expansion portions comprise longitudinally extending corrugations formed on the filtering media.  
     
     
         50 . The expandable well screen according to  claim 48 , further comprising a series of longitudinally extending and circumferentially distributed ribs positioned at least partially within the filtering media.  
     
     
         51 . The expandable well screen according to  claim 50 , wherein at least one of the ribs is positioned radially between a base pipe and one of the filtering media expansion portions.  
     
     
         52 . The expandable well screen according to  claim 48 , further comprising at least one substantially hollow longitudinally extending rib internally positioned relative to the filtering media.  
     
     
         53 . The expandable well screen according to  claim 52 , further comprising a communication line extending through the rib.  
     
     
         54 . The expandable well screen according to  claim 52 , further comprising a power line extending through the rib.  
     
     
         55 . The expandable well screen according to  claim 52 , further comprising a hydraulic line extending through the rib.  
     
     
         56 . The expandable well screen according to  claim 48 , wherein the filtering media includes a series of circumferentially extending slots formed therethrough.  
     
     
         57 . The expandable well screen according to  claim 56 , wherein the series of slots is helically arranged on the filtering media.  
     
     
         58 . The expandable well screen according to  claim 56 , wherein a width of each of the slots decreases when the filtering media is radially outwardly expanded.  
     
     
         59 . An expandable well screen, comprising: 
 a filtering media;    a series of longitudinally extending and circumferentially distributed ribs disposed externally relative to the filtering media; and    a generally tubular protective shroud outwardly overlying the ribs.    
     
     
         60 . The expandable well screen according to  claim 59 , further comprising an expansion strip connected to opposite circumferential ends of the filtering media, the expansion strip elongating circumferentially when the filtering media is radially outwardly expanded.  
     
     
         61 . The expandable well screen according to  claim 60 , wherein the expansion strip includes longitudinal corrugations formed thereon.  
     
     
         62 . The expandable well screen according to  claim 59 , wherein the filtering media includes longitudinal corrugations formed thereon, the corrugations at least partially straightening when the filtering media is radially outwardly expanded.  
     
     
         63 . The expandable well screen according to  claim 59 , wherein the filtering media includes a woven sintered filtering material.  
     
     
         64 . The expandable well screen according to  claim 63 , wherein the filtering media includes at least two layers of the woven sintered filtering material.