Abstract:
A screen jacket assembly for positioning around a base pipe ( 102 ) to form a sand control screen ( 100 ). The screen jacket assembly includes a screen jacket ( 112 ) formed from a plurality of circumferentially distributed axially extending ribs ( 114 ) and a screen wire ( 116 ) wrapped therearound. A pair of oppositely disposed connector rings ( 118, 126 ) is at least partially positionable around the first and second ends, respectively, of the screen jacket ( 112 ). The connector rings ( 118, 126 ) each have a plurality of openings ( 120, 128 ) in a sidewall portion thereof that are circumferentially alignable with at least a portion of the ribs ( 114 ) such that the connector rings ( 118, 126 ) are integrally connectable with the aligned ribs ( 114 ) via the openings ( 120, 128 ).

Description:
TECHNICAL FIELD OF THE INVENTION 
       [0001]    This invention relates, in general, to equipment utilized in conjunction with operations performed in subterranean wells and, in particular, to sand control screen assemblies having integral connector rings and methods for making same. 
       BACKGROUND OF THE INVENTION 
       [0002]    Without limiting the scope of the present invention, its background will be described with reference to producing fluid from a hydrocarbon bearing subterranean formation, as an example. 
         [0003]    Since the beginning of oil production from subsurface formations, the industry has been concerned with efficient control of the movement of unconsolidated formation particles, such as sand, into the wellbore. For example, such formation movement commonly occurs during production from completions in loose sandstone or following hydraulic fracture of a formation. Production of these materials causes numerous problems in the operation of oil, gas or water wells. These problems include plugged formations, tubing and subsurface flow lines, as well as erosion of casing, downhole equipment and surface equipment. These problems lead to high maintenance costs and unacceptable well downtime. Accordingly, numerous methods have been utilized to control the movement of these unconsolidated formation particles during the production of fluids. 
         [0004]    For example, one or more sand control screen assemblies are commonly included in the completion string to control the movement of formation particles. Such sand control screen assemblies are commonly constructed by installing one or more screen jackets on a perforated base pipe. The screen jackets typically include a single wire wrapped around a plurality of longitudinally extending ribs. Once installed on the base pipe, the ribs provide certain strength to the wire wrap and stand-off between the wire wrap and the base pipe for fluid travel. Conventionally, screen jackets have been secured to the base pipe by welding. 
         [0005]    It has been found, however, that the process of welding a screen jacket to a base pipe is sometimes very difficult due to the difference in metallurgy of the components. For example, the material used for the base pipe may be 13 chrome while the material used for the screen jacket may be a special alloy such as 304L stainless steel, 316L stainless steel, Inconel, Hastelloy or Monel. Due to the difficulty of the welding process and the post-weld heat treatment, numerous types of failures have been observed in sand control screen assemblies. For example, it has been found, that the screen wire of the screen jacket may be damaged due to the heat of the welding process. 
         [0006]    Accordingly, a need has arisen for an apparatus for attaching a screen jacket to a base pipe that does not require welding incompatibly different materials. A need has also arisen for such an apparatus that is simple and cost-effective to manufacture and that is capable of withstanding severe downhole conditions during installation and production. 
       SUMMARY OF THE INVENTION 
       [0007]    The present invention disclosed herein comprises a sand control screen assembly for preventing the inflow of formation particles during production. The sand control screen assembly of the present invention does not require welding incompatibly different materials to connect a screen jacket to the base pipe. In addition, the sand control screen assembly of the present invention is simple and cost-effective to manufacture and is capable of withstanding severe downhole conditions during installation and production. 
         [0008]    In one aspect, the present invention is directed to a screen jacket assembly for positioning around a base pipe to form a sand control screen. The screen jacket assembly includes a screen jacket formed from a plurality of circumferentially distributed axially extending ribs and a screen wire wrapped therearound. A pair of oppositely disposed connector rings is at least partially positionable around the first and second ends of the screen jacket. The connector rings each have a plurality of openings in a sidewall portion thereof that are circumferentially alignable with at least a portion of the ribs such that the connector rings are integrally connectable with the aligned ribs via the openings. 
         [0009]    In one embodiment, the connector rings may be shrink rings that are heated prior to positioning around the screen jacket such that upon cooling, a sand tight seal is created between the shrink rings and the screen jacket. In certain embodiments, the number of openings in each of the connector rings has a one to one relationship with the number of ribs. In other embodiments, the number of openings in each of the connector rings has a less than one to one relationship with the number of ribs including embodiment wherein the number of openings in each of the connector rings has a no more than one half to one relationship with the number of ribs. Once constructed, the ribs are operable to share a load between the connector rings, such as a torsional load, a tensile load, a compression load or the like. In certain embodiments, there are welded connections between the connector rings and the aligned ribs via the openings. 
         [0010]    In another aspect, the present invention is directed to a sand control screen assembly that includes a base pipe and a screen jacket operably positionable around the base pipe. The screen jacket includes a plurality of circumferentially distributed axially extending ribs and a screen wire wrapped around the ribs. A pair of oppositely disposed connector rings is at least partially positionable around the first and second ends of the screen jacket. The connector rings each have a plurality of openings in a sidewall portion thereof that are circumferentially alignable with at least a portion of the ribs such that the connector rings are integrally connectable with the aligned ribs via the openings. The connector rings are operably positionable around the base pipe. 
         [0011]    In a further aspect, the present invention is directed to a method for manufacturing a screen jacket assembly for positioning around a base pipe to form a sand control screen. The method includes forming a screen jacket including a plurality of circumferentially distributed axially extending ribs and a screen wire wrapped therearound, positioning a pair of connector rings at least partially around first and second ends, respectively, of the screen jacket, circumferentially aligning openings formed in a sidewall portion of each connector ring with at least a portion of the ribs and integrally connecting the connector rings with the aligned ribs via the openings. 
         [0012]    The method may also include heating the connector rings prior to positioning the connector rings at least partially around first and second ends of the screen jacket, cooling the connector rings after positioning the connector rings at least partially around first and second ends of the screen jacket to form a sand tight seal, sharing a torsional load between the connector rings with the ribs, sharing a tensile load between the connector rings with the ribs or weldably connecting the connector rings with the aligned ribs via the openings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0013]    For a more complete understanding of the features and advantages of the present invention, reference is now made to the detailed description of the invention along with the accompanying figures in which corresponding numerals in the different figures refer to corresponding parts and in which: 
           [0014]      FIG. 1  is a schematic illustration of a well system operating a plurality of sand control screen assemblies according to an embodiment of the present invention; 
           [0015]      FIGS. 2A-2C  are quarter sectional view of successive axial sections of a sand control screen assembly according to an embodiment of the present invention; 
           [0016]      FIGS. 2D  is a cross sectional view of a portion of a sand control screen assembly according to an embodiment of the present invention; 
           [0017]      FIG. 3  is a side view partially cut away and partially in cross section of a sand control screen assembly according to an embodiment of the present invention; 
           [0018]      FIG. 4  isometric view of one embodiment of a connector ring for use in a sand control screen assembly of the present invention; 
           [0019]      FIG. 5  isometric view of one embodiment of a connector ring for use in a sand control screen assembly of the present invention; and 
           [0020]      FIG. 6  isometric view of one embodiment of a connector ring for use in a sand control screen assembly of the present invention. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0021]    While the making and using of various embodiments of the present invention are discussed in detail below, it should be appreciated that the present invention provides many applicable inventive concepts which can be embodied in a wide variety of specific contexts. The specific embodiments discussed herein are merely illustrative of specific ways to make and use the invention, and do not delimit the scope of the present invention. 
         [0022]    Referring initially to  FIG. 1 , therein is depicted a well system including a plurality of sand control screens embodying principles of the present invention that is schematically illustrated and generally designated  10 . In the illustrated embodiment, a wellbore  12  extends through the various earth strata. Wellbore  12  has a substantially vertical section  14 , the upper portion of which has cemented therein a casing string  16 . Wellbore also has a substantially horizontal section  18  that extends through a hydrocarbon bearing subterranean formation  20 . As illustrated, substantially horizontal section  18  of wellbore  12  is open hole. 
         [0023]    Positioned within wellbore  12  and extending from the surface is a tubing string  22 . Tubing string  22  provides a conduit for formation fluids to travel from formation  20  to the surface. At its lower end, tubing string  22  is coupled to a completions string that has been installed in wellbore  12  and divides the completion interval into various production intervals adjacent to formation  20 . The completion string includes a plurality of sand control screens  24 , each of which is positioned between a pair of packers  26  that provides a fluid seal between the completion string  22  and wellbore  12 , thereby defining the production intervals. Sand control screens  24  serve the primary functions of filtering particulate matter out of the production fluid stream. In the illustrated embodiment, sand control screens  24  may also be useful in controlling the flow rate of the production fluid stream. 
         [0024]    Even though  FIG. 1  depicts the sand control screens of the present invention in an open hole environment, it should be understood by those skilled in the art that the flow control screens of the present invention are equally well suited for use in cased wells. Also, even though  FIG. 1  depicts one sand control screen in each production interval, it should be understood by those skilled in the art that any number of sand control screens of the present invention may be deployed within a production interval without departing from the principles of the present invention. Further, even though  FIG. 1  depicts each sand control screen as having a single screen jacket, it should be understood by those skilled in the art that any number of screen jackets may be installed on a single sand control screen of the present invention without departing from the principles of the present invention. 
         [0025]    In addition, even though  FIG. 1  depicts the sand control screens of the present invention in a horizontal section of the wellbore, it should be understood by those skilled in the art that the sand control screens of the present invention are equally well suited for use in deviated wellbores, vertical wellbores, multilateral wellbore and the like. Accordingly, it should be understood by those skilled in the art that the use of directional terms such as above, below, upper, lower, upward, downward, uphole, downhole and the like are used in relation to the illustrative embodiments as they are depicted in the figures, the upward direction being toward the top of the corresponding figure and the downward direction being toward the bottom of the corresponding figure, the uphole direction being toward the surface of the well and the downhole direction being toward the toe of the well. 
         [0026]    Referring next to  FIGS. 2A-2D , therein is depicted successive axial sections of a sand control screen assembly according to the present invention that is representatively illustrated and generally designated  100 . Sand control screen assembly  100  may be suitably coupled to other similar sand control screen assemblies, production packers, locating nipples, production tubulars or other downhole tools to form a completions string such as that described above. Sand control screen assembly  100  includes a base pipe  102  that has a blank pipe section  104  and a perforated section  106  including a plurality of production ports  108 . Positioned around an upper portion of blank pipe section  104  is a screen jacket  112  that serves as a filter medium and may be in the form of a single layer wire wrap screen, a multilayer wire wrap screen, a prepacked screen, a woven wire mesh screen or the like, designed to allow fluids to flow therethrough but prevent particulate matter of a predetermined size from flowing therethrough. In the illustrated embodiment, screen jacket  112  includes a plurality of circumferentially distributed axially extending ribs  114  with a screen wire  116  wrapped around the ribs. 
         [0027]    A connector ring  118  is positioned around the uphole end of screen jacket  112 . Connector ring  118  has a plurality of openings  120  in a sidewall portion thereof that are circumferentially aligned with ribs  114  of screen jacket  112 . Connector ring  118  is integrally connected with ribs  114  via welded connections  122  through openings  120 . Preferably, connector ring  118  is a shrink ring that is heated prior to positioning around screen jacket  112  such that upon cooling, a sand tight seal is created between connector ring  118  and screen jacket  112 . In the illustrated embodiment, connector ring  118  is operably associated with base pipe  102  in the form of a securable connection illustrated as weld  124 . The material of connector ring  118  is selected based upon factors including its thermal properties, its chemical resistance, its compatibility to be welded to base pipe  102 , its compatibility to be welded to screen jacket  112  and the like. Even though the material of screen jacket  112  may be incompatible for welding to base pipe  102 , the use of connector ring  118  as an intermediate device between screen jacket  112  and base pipe  102  enables welding of connector ring  118  to both base pipe  102  and screen jacket  112 . For example, suitable materials for connector ring  118  include 13 chrome, 304L stainless steel, 316L stainless steel, 420 stainless steel, 410 stainless steel, Incoloy 825 or similar alloys. In certain embodiments, connector ring  118  may be the same material of base pipe  102 , which eliminates any material incompatibility for welding. In other embodiments, connector ring  118  may be the same material of screen wire  116 , which eliminates welding directly between screen jacket  112  and base pipe  102 . In still other embodiment, connector ring  118  may be a material that is different from that of both base pipe  102  and screen wire  116 . 
         [0028]    A connector ring  126  is positioned around the downhole end of screen jacket  112 . Connector ring  126  has a plurality of openings  128 , only one being visible in  FIG. 2A , in a sidewall portion thereof that are circumferentially aligned with ribs  114  of screen jacket  112 . Connector ring  126  is integrally connected with ribs  114  via welded connections  130  through openings  128 , as best seen in  FIG. 2D . Preferably, connector ring  126  is a shrink ring that is heated prior to positioning around screen jacket  112  such that upon cooling, a sand tight seal is created between connector ring  126  and screen jacket  112 . In the illustrated embodiment, connector ring  126  is operably associated with base pipe  102  forming a fluid passageway  132  therebetween. The material of connector ring  126  is selected based upon factors including its thermal properties, its chemical resistance, its compatibility to be welded to other sand control screen components and the like. 
         [0029]    Positioned downhole of screen jacket  112  is a screen interface housing  134  that forms an annulus  136  with base pipe  102 . Preferably, screen interface housing  134  and connector ring  126  are operably associated with one another in the form of a securable connection illustrated as weld  138 . Securably connected to the downhole end of screen interface housing  134  is a sleeve housing  140 . At its downhole end, sleeve housing  140  is securably connected to a flow tube housing  142 . Flow tube housing  142  is preferably securably connected or sealably coupled to base pipe  102  to prevent fluid flow therebetween. Toward its downhole end, flow tube housing  142  is securably connected to a lower housing  144  which is preferably welded to base pipe  102  at its downhole end as indicated at  146 . The various connections of the housing sections may be made in any suitable fashion including welding, threading and the like as well as through the use of fasteners such as pins, set screws and the like. Together, the housing sections create a generally annular fluid flow path between screen jacket  112  and production ports  108  of base pipe  102 . 
         [0030]    Positioned in the annular region between housing sleeve  140  and base pipe  102  is a split ring spacer  148 . Positioned within axial openings  150  in flow tube housing  142  is a plurality of flow tubes  152 . The illustrated embodiment includes six axial openings  150  and six flow tubes  152 , only one being visible, however, those skilled in the art will recognize that other numbers of flow tubes both greater than and less than six could alternatively be used and would be considered within the scope of the present invention. Each of the flow tubes  152  is secured within flow tube housing  142  by a threaded retaining sleeve  154 . One or more of the flow tube  152  may have a threaded cap or a plug (not pictured) associated therewith to inhibit or stop flow therethrough. The use of plugs and flow tubes  152  having various inner diameters allow an operator to adjust the pressure drop rating of each sand control screen  100  to a desired level such that a completion string including a plurality of sand control screens  100  is operable to counteract heel-toe effects in long horizontal completions, balance inflow in highly deviated and fractured wells, reduce annular sand transportation and reduce water/gas influx, thereby lengthening the productive life of the well. 
         [0031]    Referring next to  FIG. 3 , therein is depicted a screen jacket assembly of the present invention that is generally designated  200 . Screen jacket assembly  200  includes a screen jacket  202  that serves as a filter medium designed to allow fluids to flow therethrough but prevent particulate matter of a predetermined size from flowing therethrough. Screen jacket  202  includes a plurality of circumferentially distributed axially extending ribs  204  with a screen wire  206  wrapped around the ribs. A pair of connector rings  208 ,  210  is positioned at opposite ends of screen jacket  202 . Connector ring  208  has a plurality of openings  212  in a sidewall portion thereof that are circumferentially aligned with ribs  204  of screen jacket  202 . Connector ring  208  is integrally connected with ribs  204  via welded connections  214  through openings  212 . Similarly, connector ring  210  has a plurality of openings  216  in a sidewall portion thereof that are circumferentially aligned with ribs  204  of screen jacket  202 . Connector ring  210  is integrally connected with ribs  204  via welded connections  218  through openings  216 . 
         [0032]    As discussed above, connector rings  208 ,  210  may be shrink rings that are heated prior to positioning around screen jacket  202 . Once in place such that openings  212 ,  216  properly align with ribs  204 , connector rings  208 ,  210  may be allowed to cool forming a sand tight seal between connector rings  208 ,  210  and screen jacket  202 . Thereafter, in the illustrated embodiment, each of the ribs  204  is integrally connected to connector ring  208  and connector ring  210 . Specifically, connector ring  208  is integrally connected to ribs  204  via welds  214  using a tungsten inert gas (TIG) welding process, a metal inert gas (MIG) welding process or other suitable welding process or connecting process. Likewise, connector ring  210  is integrally connected to ribs  204  via welds  218 . The integral connection between connector rings  208 ,  210  and ribs  204  enables ribs  204  to share a load between connector rings  208 ,  210 , such as a torsional load, a tensile load, a compression load or the like that may be applied between connector rings  208 ,  210  when a sand control screen assembly including screen jacket  202  is run in the well. 
         [0033]    Referring next to  FIG. 4 , therein is depicted a connector ring of the present invention that is generally designated  300 . Connector ring  300  may be used in conjunction with screen jacket  202  and is representative of connector ring  208  and connector ring  210 . Connector ring  300  has a substantially cylindrical body  302 . In the illustrated embodiment, connector ring  300  has a radially stepped inner profile  304  having a shoulder  306  between a radially thicker portion  308  and a radially thinner portion  310 . Preferably, shoulder  306  serves a stop and provides for axial alignment when connector ring  300  is positioned around a screen jacket. In the illustrated embodiment, connector ring  300  includes thirty openings  312  formed in the sidewall portion thereof. Once connector ring  300  is axially positioned around a screen jacket, openings  312  are preferably circumferentially aligned with an equal number of ribs of the screen jacket. Thereafter, connector ring  300  is integrally coupled to the screen jacket by, for example, welding the ribs to connector ring  300  through openings  312 . 
         [0034]    Even though connector rings  118 ,  126 ,  208 ,  210 ,  300  have been depicted and described as having a thirty openings, it should be understood by those skilled in the art that the connector rings of the present invention could have different numbers of openings either greater than or less than thirty, without departing from the principles of the present invention. The required number of openings will depend upon factors such as the diameter and design of the screen jacket. In addition, even though  FIGS. 2-4  have depicted and described connector rings  118 ,  126 ,  208 ,  210 ,  300  as having a one to one relationship between the number of openings of a connector ring and the number of ribs, it should be understood by those skilled in the art that the number openings of the connector rings of the present invention could have a different relationship to the number of ribs of the screen jacket. 
         [0035]    For example, as best seen in  FIG. 5 , connector ring  400  may be used in conjunction with screen jacket  202  and may replace connector ring  208  or connector ring  210 . Connector ring  400  has a substantially cylindrical body  402 . In the illustrated embodiment, connector ring  400  has a radially stepped inner profile  404  having a shoulder  406  between a radially thicker portion  408  and a radially thinner portion  410 . In the illustrated embodiment, connector ring  400  includes twenty openings  412  formed in the sidewall portion thereof. Once connector ring  400  is axially positioned around a screen jacket, openings  412  are preferably circumferentially aligned with an equal number of ribs of the screen jacket, which may be a subset of all the ribs of the screen jacket. Thereafter, connector ring  400  is integrally coupled to the screen jacket by, for example, welding the ribs to connector ring  400  through opening  412 . 
         [0036]    As another example, as best seen in  FIG. 6 , connector ring  500  may be used in conjunction with screen jacket  202  and may replace connector ring  208  or connector ring  210 . Connector ring  500  has a substantially cylindrical body  502 . In the illustrated embodiment, connector ring  500  has a radially stepped inner profile  504  having a shoulder  506  between a radially thicker portion  508  and a radially thinner portion  510 . In the illustrated embodiment, connector ring  500  includes fifteen openings  512  formed in the sidewall portion thereof. Once connector ring  500  is axially positioned around a screen jacket, openings  512  are preferably circumferentially aligned with an equal number of ribs of the screen jacket, which may be a subset of all the ribs of the screen jacket. Thereafter, connector ring  500  is integrally coupled to the screen jacket by, for example, welding the ribs to connector ring  500  through opening  512 . 
         [0037]    While this invention has been described with reference to illustrative embodiments, this description is not intended to be construed in a limiting sense. Various modifications and combinations of the illustrative embodiments as well as other embodiments of the invention will be apparent to persons skilled in the art upon reference to the description. It is, therefore, intended that the appended claims encompass any such modifications or embodiments.