Abstract:
Disclosed herein is an assembly for use in a wellbore which includes a base pipe; a filter medium surrounding at least a portion of the external surface of the base pipe; and an internally profiled sleeve surrounding at least a portion of the filter media. Also included is a method for attaching a hardware accessory to a sand screen assembly which includes providing a base pipe having an inner surface and an outer surface; surrounding the outer surface of the base pipe with a filter medium; engaging the sleeve with the filter medium; and connecting the hardware accessory to the sleeve. Also included is a downhole apparatus which includes a basepipe, where at least a portion of the external surface of the basepipe is profiled; and a sleeve mounted external to the basepipe, where the internal profile of the sleeve corresponds to the external profile of the basepipe.

Description:
RELATED APPLICATIONS 
     This patent application claims priority to U.S. provisional patent application Ser. No. 61/036,325 filed on Mar. 13, 2008, incorporated herein by reference. 
    
    
     BACKGROUND 
     Various subterranean formations contain hydrocarbons in fluid form which can be produced to a surface location for collection. Generally, a wellbore is drilled, and a production completion is moved downhole to facilitate production of desired fluids from the surrounding formation. Many of the formation fluids, however, contain particulates, e.g., sand, that can wear or otherwise detrimentally impact both downhole and surface components. 
     Gravel packing techniques, including frac packing procedures, are often used to control sand. In typical gravel packing operations, a slurry of gravel carried in a transport fluid is pumped into a well annulus between a sand screen and the surrounding casing or open wellbore. The deposited gravel is dehydrated (i.e., the transport fluid is removed), and the remaining gravel facilitates blocking of sand or other particulates that would otherwise flow with formation fluids into the production equipment. 
     In some gravel packing operations, difficulty arises in obtaining uniform distribution of gravel throughout the desired gravel pack region. For example, a poor distribution of gravel can result from premature loss of transport fluid, which causes the creation of bridges that can prevent or reduce further distribution of gravel past the bridge. Also, certain manmade isolation devices, such as packers, can present barriers to distribution of the gravel slurry. Shunt tubes have been used to bypass bridges and/or manmade isolation devices to ensure complete gravel packing (see, e.g., U.S. Pat. No. 7,407,007). 
     Traditionally, the method to attach hardware, such as the aforementioned shunt tubes, to oilfield sand screen tubulars (and other downhole equipment) involved welding. Unfortunately, welding often introduces stress into the tubulars that can cause defects (for example corrosion, corrosion cracking, and surface cracks) that can result in undesirable consequences, including, but not limited to failure of the tubular. Various post-welding procedures are available to minimize undesirable consequences (e.g., post-weld heat treatment to homogenize the metals or examination using dye penetrant to identify surface defects). However, these treatments can be expensive and time consuming and cause administrative hassles and only mitigate the risk of defects caused by welding rather than eliminate the risks. 
     Thus, for at least these reasons, it may be desirable to eliminate or reduce the welding necessary to attach hardware to tubulars or downhole equipment. 
     SUMMARY 
     Disclosed herein are methods to attach hardware to tubulars (such as sand screen basepipe) and other downhole equipment, including: 
     An assembly for use in a wellbore, comprising a base pipe; a filter medium surrounding at least a portion of the external surface of the base pipe; and an internally profiled sleeve surrounding at least a portion of the filter media. 
     Also included is a method for attaching a hardware accessory to a sand screen assembly, comprising providing a base pipe having an inner surface and an outer surface; surrounding the outer surface of the base pipe with a filter medium; engaging the sleeve with the filter medium; and connecting the hardware accessory to the sleeve. 
     Also included is a downhole apparatus comprising a basepipe, wherein at least a portion of the external surface of the basepipe comprises a profile; and a sleeve mounted external to the basepipe, wherein the internal profile of the sleeve corresponds to the external profile of the basepipe. 
    
    
     
       BRIEF SUMMARY OF THE DRAWINGS 
         FIG. 1  is a schematic drawing of a sandscreen deployed in a wellbore. 
         FIG. 1A  is a more detailed schematic drawing of a sandscreen adjacent to a basepipe. 
         FIG. 2  is a schematic drawing of a sandscreen and sleeve in accordance with embodiments as disclosed herein. 
         FIG. 2A  is a cross sectional view of an embodiment of a sleeve such as is shown in  FIG. 2 . 
         FIG. 2B  is an illustration depicting attachment of shunt tubes to the sleeve in accordance with an embodiment of the invention. 
         FIG. 3  is a schematic drawing of a sandscreen and sleeve in accordance with embodiments as disclosed herein. 
         FIG. 4  is a schematic drawing of non-exclusive examples of wire wrap profiles which may be used in embodiments as disclosed herein. 
         FIG. 5  is a schematic drawing of non-exclusive examples of wire wrap profiles which may be used in embodiments as disclosed herein. 
         FIG. 6  is a schematic drawing of a sandscreen and sleeve in accordance with embodiments as disclosed herein. 
         FIG. 7  is a schematic drawing of a basepipe and sleeve in accordance with embodiments as disclosed herein. 
         FIG. 8  is a schematic drawing of a sandscreen and sleeve in accordance with embodiments as disclosed herein. 
         FIG. 9A  is a schematic drawing of a basepipe having longitudinal ribs. 
         FIGS. 9B and 9D  are schematic drawings of a sleeve in accordance with embodiments as disclosed herein. 
         FIG. 9C  is a schematic drawing of a sleeve installed on a device having longitudinal ribs as disclosed herein. 
         FIGS. 10A ,  10 B, and  10 C are schematic drawings of a sandscreen and sleeve in accordance with embodiments as disclosed herein. 
     
    
    
     DETAILED DESCRIPTION 
     In the following description, numerous details are set forth to provide an understanding of the present invention. However, it will be understood by those skilled in the art that the present invention may be practiced without these details and that numerous variations or modifications from the described embodiments may be possible. 
     In the specification and appended claims: the terms “connect”, “connection”, “connected”, “in connection with”, and “connecting” are used to mean “in direct connection with” or “in connection with via another element.” As used herein, the terms “up” and “down”, “upper” and “lower”, “upwardly” and downwardly”, “upstream” and “downstream”; “above” and “below”; and other like terms indicating relative positions above or below a given point or element are used in this description to more clearly describe some embodiments of the invention. 
     With reference to  FIG. 1 , a sand screen assembly  10  is deployed in a wellbore  20  via a conveyance string  30  (e.g., coiled tubing). The sand screen assembly generally is comprised of one or more screen sections  10 A,  10 B, each of which comprise a base pipe  12  and a filter media  14  as is shown in  FIG. 1A . The base pipe  12  may be a perforated base pipe or include inflow control devices (nozzles inserts or nozzle rings with chambers). The filter media  14  may include wire-wrapped screen, mesh screen, or any other type of filter media which is known in the art. 
     In some instances, it is desirable to attach external hardware to a sand screen assembly. One non exclusive example of hardware that may be desirable to attach external to a sand screen assembly is a shunt tube which provides an alternative flow path for fluids being transported downhole, e.g., gravel pack slurry. The conventional method for attaching hardware to a sand screen assembly involves welding to the tubular base pipe. Welding, however, introduces stresses into the base pipe forming the sand screen assembly that can cause stress corrosion cracking, surface cracks, and other defects that can result in failure of the base pipe. Typical weld procedures involve a post-weld heat treatment to homogenize the pipe material to remove induced stresses. Another post-welding process for tubulars typically performed is a non-destructive weld examination using dye penetrant which identifies surface defects that can result in cracking of the tubulars. These post-welding processes often involve an in depth system of quality control documents, traceability, and personnel training. 
     Base pipe tubulars used for screen applications are normally not designed to be welded. Depending on the metallurgy and mechanical properties of the tubular, the above-mentioned heat treatment process may, in some instances, regain the tubular&#39;s integrity. With increased yield of the tubular and more sophisticated metallurgy, regaining integrity after welding may, however, not be possible. Accordingly, in many applications, welding of the tubulars may permanently reduce its integrity. Eliminating welding to the base pipe tubular reduces the measures necessary to assure the base pipe integrity has not been compromised and the amount of quality assurance personnel time and documentation. 
     In one embodiment, as shown in  FIG. 2 , a sand screen assembly  110  is provided having a base pipe  112  surrounded by wire-wrapped screen  114 . In this embodiment, the wire-wrap screen  114  has a dome-shape profile  114 A positioned on the outside of the wire-wrap screen  114  (direct-wrap or slip-on wrap). A sleeve  120  having ports  122  is machined (or otherwise formed with a particular profile) on its inner diameter such that the inner profile  120 A of the sleeve mates the dome-shaped outer profile  114 A of the screen  114 , and can be threadably connected thereon, essentially creating a nut-and-bolt joint where the sleeve is the nut and the wire-wrap screen is the bolt. Alternatively, the wrap wire could be flat on the outside and the slot opening of the wrap wire could be sufficiently wide such that a sleeve could have an inner diameter profile that engages the slot opening of the wrapped wire. These nut-and-bolt configurations allow for the transfer of axial load through the direct wrap screen into the base pipe. Indeed, other embodiments may include any shaped wrap wire whether round or shaped with multiple sides where the sides can be flat, rounded or scuffed (such as sand/bead blasted) such that the inner profile of the sleeve can be mated thereto in threaded engagement. This sleeve  120  thereby provides a surface external the base pipe  112  and isolated from the base pipe via the wire wrap filter  114  on which accessories or external hardware can be connected even by welding without reducing the integrity of the base pipe tubular, such that, for example, shunt tubes  152  (see  FIG. 2B ) may be attached via hardware  150  to the sleeve  120 . Still further, in alternative embodiments, the wrap wire screen  114  can be designed with a protruding profile such that it provides a contact area for the “threaded sleeve” thus providing a greater loading capacity. After the wire is wrapped as a screen filter the resulting protruding feature will provide a significant thread contact area. The protruding profile of the wrap wire can have any shape or height (see  FIG. 4  for non-exclusive examples of protruding profiles which it may be desirable to have on the wire wrap). 
     In other embodiments, still with respect to  FIG. 2 , additional features can be added to the sleeve  120  to increase its axial and torsional loading capacity. For example, the sleeve  120  can be designed to provide an interference fit by machining its inner diameter “female thread” profile to match or have an interference with the wire wrap jacket “male thread” profile provided by the wrap wire. As is shown in  FIG. 2A , the sleeve could include a longitudinal split  124 , which, when the sleeve is positioned on the wire wrap jacket  114  and the sleeve is clamped in place, could be welded along the split or bolted together or using a similar method to attach the two sides. The shrinking of the weld during cooling creates a squeeze of the sleeve onto the wire wrap jacket outer diameter. Or, alternatively, the sleeve  120  could be heated to expand the sleeve thus allowing it to be positioned on the wire wrap screen and then subsequent cooling of the sleeve would allow the sleeve to shrink-fit onto the wire wrap screen  114 . 
     The sleeve  120  can also be designed to have holes  122  in it within which plug welds can be placed thus welding the sleeve to the outer diameter surface of the wire wrap jacket  114 . The number of holes and plug welds can be adjusted to meet the torsional and axial loading capacity requirements as would be determined by one of ordinary skill in the art. 
     In other embodiments, the sleeve  120  could be coated on the inner diameter with an adhesive (e.g., JBWeld available from JB-Weld Company of Sulphur Springs, Tex. (www.jbweld.net or Loctite available from Henkel Int&#39;l (www.loctite.com) or other adhesive as would be known to one of ordinary skill in the art), which, when put in place, bonds with the wire wrap jacket outer diameter providing substantially complete contact area for resisting torsion and axial loading. 
     The sleeve can be designed to implement all features above simultaneously or select ones. Moreover, the various sleeve embodiments can be applied either anywhere along the wire wrap screen (as shown in  FIG. 2  and discussed above) or at the termination of the wire wrapped screen (as shown in  FIG. 3 ). The embodiment shown in  FIG. 3  includes the same features as described above for  FIG. 2 , except that the sleeve  120  may also be connected (e.g., by weld or other) to the end ring (load ring or termination ring)  118 , where the end ring provides a weld surface isolated from the base pipe. 
     In yet another embodiment the wrap wire of an already-wrapped wire wrap screen  200  can be machined to have a protruding profile  210  that provides a contact area for the “threaded sleeve.” This embodiment is similar to that described above except that the profile is machined after wrapping as opposed to the wrap wire having the desired profile before wrapping.  FIG. 5  depicts a protruding profile  210  created by machining/grinding the wrap wire of an already-wrapped screen. Some of the material on the edge of the wrapping wire is removed to make the slot opening bigger and thus making it possible for the “threads” on the ID of the sleeve to engage into the bigger slots created between the wrapping. 
     With reference to  FIG. 6 , in a further embodiment, a sleeve  320  can be mechanically joined to a base pipe  330  by pinning. A sleeve  320  and base pipe  330  can be drilled with matching holes in which pins  340  are inserted to provide a joint that can withstand axial and torsion loads. To prevent the pins from backing out they may be of a weldable material or alternatively, they may be covered by a weldable retaining pin  310  which is then welded on by welds  300 . The number of holes/pins is determined by one of ordinary skill in the art without undue experimentation with consideration of the strength of the pin, sleeve, and base pipe materials and the size of the holes and pins. 
     With reference to  FIG. 7 , a sleeve  410  can be mechanically joined to a base pipe  400  by cutting, forming, or grinding a recess  420  in the base pipe outer diameter and sleeve inner diameter and installing a heat-expanded sleeve  410  over the recess  420  and allowing the sleeve to cool and shrink into the recess. This joint requires the inner diameter of the sleeve  410  to be equal to or less than the recess  420  outer diameter machined into the base pipe  400 . The recess profile in the base pipe  400  can have multiple recesses providing greater axial loading resistance. Alternatively, the sleeve can be split axially (not shown) and the split welded once positioned creating a shrink fit upon cooling of the weld similar to  124  in  FIG. 2A . 
     With reference to  FIG. 8 , due to the tapered top of the wrap wire  500 , the screen outer diameter can be machined down  510  to expose more space/width  520  between wrap wires. A sleeve can be machined with an inner diameter thread profile that matches opening width of the machined wrap wire. 
     With reference to  FIGS. 9A ,  9 B,  9 C, and  9 D, as is well known in the art, it is often desirable to run axial ribs  700  along the basepipe  710  below the filter layer (e.g., the wire wrap) (not shown for clarity). When installed on the base pipe,  710 , the sleeve  820  can have threads that extend through the filter medium and into the axial wire profile where the sleeve&#39;s threads are “cut out”  810  to allow the axial wires  700  to pass through the sleeve threads. This allows the sleeve  820  to engage the axial wires  700  thus allowing the transfer of torque through the axial wires. A schematic view of the inside of the sleeve  820 , unfolded, is shown in  FIG. 9D  in which the internal “threads”  830  on the sleeve not only have spaces  800  for the wire wrap, but also have spaces  810  to fit within the axial ribs  700  to provide the transfer of torque through the axial wires. 
     With reference to  FIGS. 10A ,  10 B, and  10 C, a direct wrap wire wrap jacket has a gap between two wrapped sections  600  and  610  where one of the sections have axial wires running below the wire wrap jacket exposed  620  and the other section has the axial wires cut flush with the wrap wire (not shown, hidden below wire wrap  610 ). A split ring  630  having a profile  670  on its inner diameter for mating with the axial wires is installed in the region of no axial wires. With both halves on base pipe the two halves are slid to engage with the axial wires  620 . A second split ring  640  with a stepped inner diameter profile is placed between the previously installed split ring  630  and the wrapped section without axial wires exposed  610 . The second ring traps the two rings in place. The two rings are welded together at weld  650 . Both rings have an extension that resides over the wrap wire of the jacket which provides sand control for the jacket termination. The axial wires provide torque resistance and the jacket sections provide axial load resistance. 
     In all embodiments of the present invention, the terms “sleeve” and “ring” may be used interchangeably. Moreover, it is the intention of the present invention that each embodiment described herein provides a surface external the base pipe on which accessories/hardware may be connected to the sand screen assembly, as by welding, bolting, or any other acceptable method as would be determined by one of ordinary skill in the art without undue experimentation. 
     While the invention has been disclosed with respect to a limited number of embodiments, those skilled in the art will appreciate numerous modifications and variations therefrom. It is intended that the appended claims cover such modifications and variations as fall within the true spirit and scope of the invention.