BACKGROUND
The invention generally relates to a downhole screen assembly.
For purposes of filtering particulates from produced well fluid, a well fluid production system may include sandscreen assemblies. Each sandscreen assembly typically includes a screen (a wire wrap or a woven wire mesh, as an example), which contains openings that are sized to allow the communication of well fluid into the interior space of the assembly while suppressing sand production. The interior space of the sandscreen assembly is in communication with production tubing.
SUMMARY
In an embodiment of the invention, a screen assembly that is used with a well includes base pipe, a screen and ribs. The base pipe has a non-perforated section and has a longitudinal axis. The screen at least partially circumscribes the non-perforated section of the base pipe, and the ribs extend longitudinally in an annular space between the screen and the non-perforated section. A flexible member of the screen assembly is wrapped around the ribs and is disposed in the annular space.
In another embodiment of the invention, a screen assembly that is usable with a well includes a base pipe, a screen and a corrugated material. The screen at least partially circumscribes the base pipe, and the corrugated material is located in an annular space between the screen and the base pipe.
In another embodiment of the invention, a screen assembly that is usable with a well includes a base pipe, a screen, a first set of flexible members and a second set of flexible members. The screen at least partially circumscribes the base pipe, and the first set of flexible members extend longitudinally in an annular space between the screen and the non-perforated section. The second set of flexible members is interwoven with the first set of flexible members.
In another embodiment of the invention, a screen assembly that is usable with a well includes a base pipe, and a screen. The base pipe has a longitudinal axis, and the screen at least partially circumscribes the base pipe. One or more members of the screen assembly extend longitudinally in an annular space between the screen and the base pipe. Each member includes a base portion and at least two side walls to form at least one longitudinal channel.
In yet another embodiment of the invention, a screen assembly that is usable with a well includes a base pipe and a screen. The base pipe has a longitudinal axis, and the screen at least partially circumscribes the base pipe. Longitudinal channels are formed in the base pipe and are at least partially circumscribed by the screen.
Advantages and other features of the invention will become apparent from the following drawing, description and claims.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a schematic diagram of a well according to an embodiment of the invention.
FIG. 2 is a schematic diagram of a screen assembly according to an embodiment of the invention.
FIG. 3 is a cross-sectional view taken along line 3-3 of FIG. 2 according to embodiments of the invention.
FIG. 4 is a cross-sectional view of the screen assembly illustrating a corrugated material spacer of the assembly according to an embodiment of the invention.
FIG. 5 is a perspective view of a section of the screen assembly illustrating a perforated and corrugated material used as an annular standoff in the assembly according to an embodiment of the invention.
FIG. 6 is a perspective view of an alternative annular standoff created using woven metal wires according to an embodiment of the invention.
FIGS. 7, 8, 9 and 10 depict annular standoffs that are formed from members that have longitudinal channels according to different embodiments of the invention.
FIG. 11 is a perspective view of a section of a base pipe of a screen assembly depicting axial grooves that are formed in the outer surface of the base pipe according to an embodiment of the invention.
DETAILED DESCRIPTION
Referring to FIG. 1, an embodiment 10 of a well (a subsea well or a subterranean well) in accordance with the invention includes a tubular string 20 that is disposed inside a wellbore 24. Although the wellbore 24 is depicted in FIG. 1 as being a vertical wellbore, the wellbore 24 may be a deviated or a horizontal wellbore in accordance with other embodiments of the invention. As depicted in FIG. 1, the tubular string 20 traverses a particular production zone 30 of the well 10. For purposes of example, the production zone 30 is shown in FIG. 1 as being formed between upper 32 and lower 36 annular isolation packers.
Inside the production zone 30, the tubular string 20 includes a series of connected sandscreen assemblies, each of which includes a sandscreen section 40 and an associated inflow control device 42. It is noted that although one sandscreen section 40 and one inflow control device 42 are depicted in FIG. 1, it is understood that the tubular string 20 and the production zone 30 in particular may include multiple inflow control devices 42 and sandscreen sections 40, in accordance with embodiments of the invention.
The inflow control device 42, as it name implies, regulates the flow of well fluid from the annulus that immediately surrounds the associated sandscreen section 40, through the sandscreen section 40 and into the central passageway of the tubular string 20. Thus, the tubular string 20 has multiple inflow control devices 42, each of which is associated with a sandscreen section 40 and has an associated flow characteristic for purposes of establishing a relatively uniform flow distribution from the production zone 30.
Various embodiments of the invention are set forth herein relating to different designs for the screen assembly. In particular, various annular standoff designs for the screen assembly are described herein for purposes of forming an annular space between a filter (a woven wire or metal fiber filter) and a base pipe of the screen assembly. The annular space receives well fluid that flows through the filter, and the well fluid is communicated through radial perforations, or openings, in the base pipe into the base pipe's central passageway. Depending on the particular embodiment of the invention, the filter may or may not circumscribe the portion of base pipe, which contains the openings.
FIG. 2 depicts a partial schematic view of the screen assembly 40 in accordance with some embodiments of the invention. Although FIG. 2 depicts a lefthand cross-sectional view of the screen assembly 40 along a longitudinal axis 50, it is understood that the screen assembly 40 is generally symmetric about the longitudinal axis 50, with the depiction of the right hand side of the assembly being omitted from FIG. 2.
Referring to FIG. 2 in conjunction with the cross-section that is depicted in FIG. 3, in general, the screen assembly 40 includes an inner base pipe 60, which includes a non-perforated section 60a, which is circumscribed by a screen, or filter 100, such as a woven wire mesh filter or a metal fiber filter, depending on the particular embodiment of the invention. A perforated and tubular protective shroud 80 surrounds the filter 100 about the longitudinal axis 50 and permits fluid to be communicated through its perforations and pass through the filter 100 into longitudinal passageways 121 (see cross-section of FIG. 3), which are formed between longitudinally, or axially, extending wire ribs 120. The ribs 120 may have many differential cross-sectional forms (round, rectangular, etc.), depending on the particular embodiment of the invention. The incoming fluid flow flows through these longitudinal passageways 121 into an annular space 140, where the fluid is received in a perforated section 60b of the base pipe 60. In this regard, in the perforated section 60b, the base pipe 60 includes various nozzles, which contain specifically-sized orifices for purposes of regulating the flow into the screen assembly.
The longitudinally extending ribs 120 form a substantial part of the annular standoff between the base pipe 60 and the filter 100. In accordance with embodiments of the invention described herein, a spirally-wrapped flexible member, such as a wire 190, is concentric with the longitudinal axis 50 extends around the longitudinal ribs 120 for purposes of providing additional inner support for the filter 100. The wire 190 may have many differential cross-sectional forms (round, rectangular, etc.), depending on the particular embodiment of the invention. It is noted that, as depicted in FIGS. 2 and 3, the cross-sectional dimension of the wire 190 may be significantly smaller than the cross-sectional dimension of each of the longitudinal ribs 120. Thus, the cross-sectional dimension of the longitudinal rib 120 effectively establishes the radial standoff distance between the filter 100 and the base pipe 60.
The gap between the wrapped wire 190 and the longitudinal ribs 120 is sufficiently close such that the filter 100 under collapse conditions cannot deform into the annular flow area and reduce the annular flow area.
Among the other features of the screen assembly 40, in accordance with some embodiments of the invention, the screen assembly 40 includes an upper housing section 70, which is attached to the outer surface of the base pipe 60 and provides support for the shroud 80 and the filter 100. In this regard, the filter 100 may be part of an assembly that includes solid sections 90 and 92. The screen assembly 40 may also include a cover 160 that controls access to the annular space 150 and a middle housing section 130 which provides lower support for the shroud 80 and support for the cover 160. The cover 160 is also supported by a lower housing section 180, that is attached to the outer surface of the base pipe 60.
Referring to FIG. 4, in another embodiment of the invention, the annular standoff may be alternatively provided by a corrugated sheet material 200, which is disposed in the annular region between the filter and the base pipe 60. FIG. 4 depicts the outer protective shroud 80 with it being understood in that the filter 100 is disposed between the shroud 80 and the corrugated material 200. As a more specific example, the corrugated material 200 may be a metal, and the corrugated material 200 may be perforated (see FIG. 5), for purposes of allowing fluid to flow through the corrugated material 200 and along the longitudinal axis 50 of the base pipe 60 on the inner side of the corrugated material 200.
In other embodiments of the invention, the corrugated material 200 may be solid and thus, may not be perforated in an arrangement in which the fluid flow is confined to the outside surface of the corrugated material 200.
In accordance with other embodiments of the invention, an annular standoff may be achieved using a wire mesh 220, which is depicted in FIG. 6. As shown, the wire mesh 220 includes a first set of longitudinally, or axially, extending wires 230 (warp wire, for example), which is interwoven with a second set of laterally extending smaller wires 240 (weft wire, for example).
Referring to FIGS. 7-10, the annular standoff may be created using rails that contain axial channels on their outer or inner surfaces, depending on the particular embodiment of the invention. More specifically, FIG. 7 depicts longitudinally-extending members 250, each of which has a corresponding channel that faces the wire filter and faces away from the base pipe 60. Each member 250 includes two side walls 254 and a corresponding base section 256. This arrangement creates a substantially U-shaped cross section, which is open, as indicated at reference numeral 260. As depicted in FIG. 8, in some embodiments of the invention, the longitudinal members 250 may be combined in a single, integrated member 270, which contains multiple longitudinal channels 280. As shown in FIG. 8, the multiple longitudinal channels 280 confine flow between the member 270 and the filter 100.
Referring to FIGS. 9 and 10, in accordance with some embodiments of the invention, flow may be confined between the longitudinal member and the outside surface of the base pipe 60. More specifically, FIG. 9 depicts longitudinally-extending members 300, which have U-shaped channels 302 that are formed between a base portion of each of the members 300 and the exterior surface of the base pipe 60. Perforations 304 are formed in the members 300 for purposes of allowing fluid communication between the channels and the filter 100. FIG. 10 depicts the integration, or consolidation, of the members 300 into a single piece or integrated member 320, which contains multiple longitudinal channels 324. The member 320 includes a base plate 340, which includes perforations 330 for purposes of establishing communication between the channels and the filter 100.
As another variation, in accordance with other embodiments of the invention, an annular standoff may be formed by longitudinal members that have axial channels on the outside (such as the longitudinal members 250 (FIG. 7) or 270 (FIG. 8)) in combination with a helically wrapped flexible member (such as a wire) around these members, similar to the wire 190 (see also FIG. 2). This arrangement provides additional support for the filter 100, thereby preventing deformation of the filter 100 into the otherwise open channels under collapse conditions.
In yet another variation, FIG. 11 depicts a standoff that is created by creating (milling, for example) longitudinal channels 360 in the outer surface of the base pipe 60 to provide the required flow area. The filter 100 is positioned directly over the channels 360. As an alternative, an additional support layer may be disposed over the longitudinal channels 360 and located between the outer surface of the base pipe 60 and the filter 100. In this manner, this additional support layer may be constructed of, as example, woven mesh, welded square mesh, perforated sheet metal, helically wrapped wire, or any other support layer that prevents the mesh filter from deforming into the longitudinal channels 360.
While the present invention has been described with respect to a limited number of embodiments, those skilled in the art, having the benefit of this disclosure, will appreciate numerous modifications and variations therefrom. It is intended that the appended claims cover all such modifications and variations as fall within the true spirit and scope of this present invention.