Patent Description:
To gravel pack a completion, a screen is lowered on a workstring into the wellbore and is placed adjacent the subterranean formation. Particulate material, collectively referred to as "gravel," and a carrier fluid, is pumped as slurry down the workstring. Eventually, the slurry exits through a "cross-over" into the wellbore annulus formed between the screen and the wellbore.

The carrier fluid in the slurry normally flows into the formation and/or through the screen. However, the screen is sized so that gravel is prevented from flowing through the screen. This results in the gravel being deposited or "screened out" in the annulus between the screen and the wellbore to form a gravel-pack around the screen. Moreover, the gravel is sized so that it forms a permeable mass that allows produced fluids to flow through the mass and into the screen but blocks the flow of particulates into the screen.

Due to poor distribution of the gravel, it is often difficult to completely pack the entire length of the wellbore annulus around the screen. This can result in an interval within the annulus that is not completely gravel packed. The poor distribution of gravel is often caused by the carrier liquid in the slurry being lost to more permeable portions of the formation. Due to the loss of the carrier liquid however, the gravel in the slurry forms "sand bridges" in the annulus before all of the gravel has been placed around the screen.

Such bridges block further flow of the slurry through the annulus, thereby preventing the placement of sufficient gravel below the bridge in top-to-bottom packing operations or above the bridge in bottom-to-top packing operations. Alternate flow conduits, called shunt tubes, can alleviate this bridging problem by providing a flow path for the slurry around such sand bridges. The shunt tubes are typically run along the length of the screen and are attached to the screen by welds.

There is a need for a shroud assembly to protect the jumper tube connection assembly. <CIT> proposes a procedure and an arrangement for coating a bare joint between two pipes.

The present invention provides a shroud assembly in accordance with claim <NUM>.

So that the manner in which the above recited features of the present invention can be understood in detail, a more particular description of the invention, briefly summarized above, may be had by reference to embodiments, some of which are illustrated in the appended drawings. It is to be noted, however, that the appended drawings illustrate only typical embodiments of this invention and are therefore not to be considered limiting of its scope, for the invention may admit to other equally effective embodiments.

<FIG> illustrates an exemplary embodiment of a shroud assembly <NUM>. <FIG> is a cross-sectional view of the shroud assembly <NUM> of <FIG>. <FIG> is an end view of the shroud assembly <NUM>. In this embodiment, the shroud assembly <NUM> is used to protect a jumper tube assembly <NUM> for coupling shunt tubes 106A, 106B attached to a tubular string, such as a screen <NUM>. The shroud assembly <NUM> includes two semi-cylindrical covers <NUM>, <NUM> having a first end attachable to a first receiver ring <NUM> and a second end attachable to a second receiver ring <NUM>. In one example, the two covers <NUM>, <NUM> are attached to the receiver rings <NUM>, <NUM> using a pin connection, as shown in <FIG>. In another example, the two covers are attached to the receiver rings using a dovetail connection, as shown in <FIG> as will be described below.

As shown in <FIG>, each cover <NUM>, <NUM> includes one or more pins <NUM> extending out of each end. For example, three pins <NUM> extend out of each end of each cover <NUM>, <NUM>. The pins <NUM> engage a respective slot <NUM> formed on the exterior surface of the receiver rings <NUM>, <NUM>. In one embodiment, the first receiver ring <NUM> is fixed relative to the screen <NUM>. The second receiver ring <NUM> is movable relative to the screen <NUM> and toward the first receiver ring <NUM>. In one embodiment, a plurality of pins <NUM> are circumferentially spaced around each cover <NUM>, <NUM>. As shown in <FIG>, three pins <NUM> are disposed at each end of the covers <NUM>, <NUM>. In some embodiments, the pins <NUM> are spaced sufficiently such that the covers <NUM>, <NUM> cannot move radially away from the receiver rings <NUM>, <NUM>. In this respect, the covers <NUM>, <NUM> are attached to the receiver rings <NUM>, <NUM> as long as the pins <NUM> are in the slots <NUM> of the receiver rings <NUM>, <NUM>.

The shroud assembly <NUM> also includes a base ring <NUM> and an extender ring <NUM>. The base ring <NUM> is attached to the screen <NUM> and includes grooves <NUM> to accommodate the shunt tubes 106A. In this example, the base ring <NUM> includes a bore <NUM> for holding the screen <NUM>, and both grooves <NUM> are formed less than <NUM> degrees apart. The screen bore <NUM> is an eccentric bore relative to a central axis of the base ring <NUM>. One end of the extender ring <NUM> is threadedly coupled to the base ring <NUM>, and the other end of the extender ring <NUM> abuts the second receiver ring <NUM>. The extender ring <NUM> is configured to move the second receiver ring <NUM> toward the first receiver ring <NUM>. In one example, the rotation of the extender ring <NUM> relative to the base ring <NUM> causes axial movement of the second receiver ring <NUM> away from the base ring <NUM> and toward the first receiver ring <NUM>. In one embodiment, a torque key <NUM> extends from a slot <NUM> in the base ring <NUM> to a slot in the second receiver ring <NUM>. The second receiver ring <NUM> moves axially relative to the torque key <NUM>.

During assembly, the pins <NUM> of the covers <NUM>, <NUM> are aligned with the respective slots <NUM> of the first and second receiver rings <NUM>, <NUM>. In this example, the pins <NUM> at one end are aligned with the slots <NUM> of the first receiver ring <NUM> and then inserted to at least partially overlap with the slots <NUM> of the first receiver ring <NUM>. Thereafter, the extender ring <NUM> is rotated relative to the base ring <NUM> to urge the second receiver ring <NUM> toward the first receiver ring. During movement, the pins <NUM> at the other end of the cover <NUM>, <NUM> are aligned and inserted into the slots <NUM> of the second receiver ring <NUM>. The extender ring <NUM> may be rotated until the pins <NUM> of the covers <NUM>, <NUM> are prevented from axially moving out of disengagement with one of the slots <NUM>. In one example, the second receiver ring <NUM> are moved toward the first receiver ring <NUM> until the covers <NUM>, <NUM> cannot move axially relative to the first receiver ring <NUM>, thereby locking the covers <NUM>, <NUM> in position. <FIG> shows the shroud assembly <NUM> assembled on the screen <NUM>. In some embodiments, the covers <NUM>, <NUM> can be attached to the first and second receiver rings <NUM>, <NUM> using a suitable fastener. Optionally, holder openings <NUM>, <NUM> may be formed in each of the covers <NUM>, <NUM> for connection to a handle to facilitate handling of the covers <NUM>, <NUM>.

<FIG> illustrates another embodiment of a shroud assembly <NUM>. <FIG> is an end view of the shroud assembly <NUM>. <FIG> is a perspective of the shroud assembly <NUM> installed on a tubular string. The shroud assembly <NUM> is used to protect a jumper tube assembly <NUM> for coupling shunt tubes 106A, 106B attached to a tubular string, such as a screen <NUM>. In this embodiment, the shroud assembly <NUM> uses a dovetail connection for coupling the covers <NUM>, <NUM> to the receiver rings <NUM>, <NUM>. The shroud assembly <NUM> includes two semi-cylindrical covers <NUM>, <NUM> having a first end attachable to a first receiver ring <NUM> and a second end attachable to a second receiver ring <NUM>. Each receiver ring <NUM>, <NUM> includes a bore <NUM> to house the screen <NUM> and includes shunt bores <NUM> to accommodate the shunt tubes 106A, 106B. In this example, both shunt bores <NUM> are formed less than <NUM> degrees apart. The screen bore <NUM> is an eccentric bore relative to a central axis of the receiver rings <NUM>, <NUM>.

As shown in <FIG>, each cover <NUM>, <NUM> includes one or more dovetails <NUM> extending out of each end. For example, three dovetails <NUM> extend out of each end of each cover <NUM>, <NUM>. The dovetails <NUM> engage a respective slot <NUM> formed on the exterior surface of the receiver rings <NUM>, <NUM>. In one embodiment, the first receiver ring <NUM> is fixed relative to the screen <NUM>. The second receiver ring <NUM> is movable relative to the screen <NUM> and toward the first receiver ring <NUM>. In one embodiment, a plurality of dovetails <NUM> are circumferentially spaced around each cover <NUM>, <NUM>. As shown in <FIG>, three dovetails <NUM> are disposed at each end of the covers <NUM>, <NUM>. In some embodiments, the dovetails <NUM> are spaced apart sufficiently such that the covers <NUM>, <NUM> cannot move radially away from the receiver rings <NUM>, <NUM>. In this respect, the covers <NUM>, <NUM> are attached to the receiver rings <NUM>, <NUM> as long as the dovetails <NUM> are in the slots <NUM> of the receiver rings <NUM>, <NUM> and cannot move axially out of engagement with the slots <NUM>. In this example, a dovetail <NUM> is located at opposite edges of the end of the cover <NUM>, <NUM>. In some embodiments, the dovetails <NUM> at located at the edges are smaller in width than the dovetail <NUM> located between them.

The shroud assembly <NUM> also includes a base ring <NUM> and an extender ring <NUM>. The base ring <NUM> is attached to the screen <NUM> and includes grooves <NUM> to accommodate the shunt tubes 106A. In this example, the base ring <NUM> includes a bore for holding the screen <NUM>, and both grooves <NUM> are formed less than <NUM> degrees apart. The screen bore is an eccentric bore relative to a central axis of the base ring <NUM>. One end of the extender ring <NUM> is threadedly coupled to the base ring <NUM>, and the other end of the extender ring <NUM> abuts the second receiver ring <NUM>. The extender ring <NUM> is configured to move the second receiver ring <NUM> toward the first receiver ring <NUM>. In one example, the rotation of the extender ring <NUM> relative to the base ring <NUM> causes axial movement of the second receiver ring <NUM> away from the base ring <NUM> and toward the first receiver ring <NUM>. In one embodiment, a torque key <NUM> extends from a slot in the base ring <NUM> to a slot in the second receiver ring <NUM>. The second receiver ring <NUM> moves axially relative to the torque key <NUM>.

During assembly, the dovetails <NUM> of the covers <NUM>, <NUM> are aligned with the respective slots <NUM> of the first and second receiver rings <NUM>, <NUM>. In this example, the dovetails <NUM> at one end are aligned with the slots <NUM> of the first receiver ring <NUM> and then inserted to at least partially overlap with the slots <NUM> of the first receiver ring <NUM>. Also, the dovetails <NUM> at the other end of the cover <NUM>, <NUM> are aligned and inserted into the slots <NUM> of the second receiver ring <NUM>. Thereafter, the extender ring <NUM> is rotated relative to the base ring <NUM> to urge the second receiver ring <NUM> toward the first receiver ring. The extender ring <NUM> may be rotated until the dovetails <NUM> of the covers <NUM>, <NUM> are prevented from axially moving out of disengagement with one of the slots <NUM>. In one example, the second receiver ring <NUM> are moved toward the first receiver ring <NUM> until the covers <NUM>, <NUM> cannot move axially relative to the first receiver ring <NUM>, thereby locking the covers <NUM>, <NUM> in position. <FIG> shows the shroud assembly <NUM> assembled on the screen <NUM>. In some embodiments, the covers <NUM>, <NUM> can be attached to the first and second receiver rings <NUM>, <NUM> using a suitable fastener.

<FIG> illustrates another exemplary embodiment of a shroud assembly <NUM>. <FIG> is an enlarged partial view of the shroud assembly <NUM>. <FIG> is an end view of the shroud assembly <NUM>. <FIG> is a cross-sectional view of the receiver ring of the shroud assembly <NUM> of <FIG>. In this embodiment, the shroud assembly <NUM> is used to protect a jumper tube assembly <NUM> for coupling shunt tubes <NUM> attached to a tubular string, such as a screen <NUM>. The shroud assembly <NUM> includes two semi-cylindrical covers <NUM> (only one shown for clarity) having a first end attached to a first receiver ring <NUM> and a second end attachable to a second receiver ring <NUM>. The receiver rings <NUM>, <NUM> are made of two semi-circular halves that are pivotally coupled to each other using a hinge <NUM>. The receiver rings <NUM>, <NUM> have an inner profile <NUM> configured to accommodate the screen <NUM> and the shunt tubes 306A, 306B. In the example shown in <FIG>, the inner profile <NUM> accommodating the screen <NUM> and the shunt tubes <NUM> is contiguous. The covers <NUM>, <NUM> are attached to a flange <NUM> of the receiver rings <NUM>, <NUM>. In one example, the flange <NUM> is formed by welding a flange ring to the receiver ring <NUM>, <NUM>. The two halve of the receiver rings <NUM>, <NUM> may be locked together using a fastener <NUM>, such as a screw, a self-retaining mechanism, a bolt, or other suitable fasteners. In some embodiments, the flange can be machined on the receiving ring.

The first receiver ring <NUM> may be positioned adjacent a base ring <NUM> attached to the screen <NUM>. One or more torque keys <NUM> extend from a slot in the base ring <NUM> to a slot <NUM> in the first receiver ring <NUM>. <FIG> shows two torque keys <NUM> coupling the receiver ring <NUM> to the base ring <NUM>.

In one embodiment, an intermediate receiver ring <NUM> may be used to extend the length of the shroud assembly <NUM>. In the <FIG>, the intermediate receiver ring <NUM> has a flange <NUM> on both ends. The flanges <NUM> allow a cover <NUM> to be attached to each end of the intermediate receiver ring <NUM>.

Embodiments of the shroud assembly described herein are suitable for protecting other downhole devices. For example, the shroud assembly can be used to protect a wire, cable, coil, electronic devices, and other downhole devices.

In some embodiments, the nozzles on the shunt tubes may be configured to control the pressure drop along the length of the shunt tubes. In general, the shunt tubes transport the slurry along the screen. The nozzles of the shunt tubes are used to eject the slurry out into the annular area between the screen and the wellbore. In some embodiments, the total amount of fluid outflow at each joint or group of joints is different.

<FIG> shows a shunt tube having a plurality of joints <NUM>-<NUM>, according to one embodiment. Each joint <NUM>-<NUM> of the shunt tube may have a different number of nozzles <NUM>-<NUM>. In particular, the number of nozzles increases as the shunt tube extend deeper into the wellbore. In one specific example, a first upper joint may have X number of nozzles, and the next joint may have one more nozzle, i.e., X+<NUM> nozzles. The third joint down may have two more nozzles. It is contemplated that the number of nozzles on the subsequent joint may increase by more than <NUM>, such as by, <NUM>, <NUM>, <NUM>, <NUM>, or <NUM> nozzles. In this example, the uppermost joint, joint <NUM>, does not have any nozzles. The next joint, joint <NUM>, has a single nozzle <NUM>. Joint <NUM> has two nozzles <NUM>, and joint <NUM> has three nozzles <NUM>. The lowermost joint, joint <NUM>, has four nozzles <NUM>.

In another embodiment, a group of joints may have the same number of nozzles, while the next group of joints may have more or less nozzles. For example, a group of Z joints may have Y number of nozzles, and the next group of Z joints may each have <NUM> more or fewer nozzles. In the example of <FIG>, group <NUM> includes joints <NUM> and <NUM>. Each of these joints has <NUM> nozzles <NUM>. Group <NUM> includes joints <NUM> and <NUM>, each of which has <NUM> nozzles <NUM>.

In another embodiment, the size of the nozzles may increase as the shunt tubes extend deeper into the wellbore. In yet another embodiment, the size of the nozzles increase, while the number of nozzles remains the same as the shunt tubes extend deeper into the wellbore. In yet another embodiment, the size and/or the number of nozzles may change as the shunt tubes extend deeper into the wellbore.

In another embodiment, the spacing of the nozzles may change as the shunt tubes extend deeper into the wellbore. For example, the spacing of nozzles may decrease as the shunt tubes extend deeper into the wellbore.

In some embodiments, a tubular string assembly includes a plurality of receiver rings; a tubular string disposed through the plurality of receiver rings; a shunt tube assembly supported by the plurality of receiver rings, the shunt tube assembly including a jumper tube assembly; and two semi-cylindrical covers disposed attached to the plurality of receiver rings and enclosed around the tubular string.

In one or more of the embodiments described herein, the assembly includes an extender ring configured to move a first receiver ring toward a second receiver ring.

In one or more of the embodiments described herein, wherein the covers enclose the jumper tube assembly.

In one embodiment, a shroud assembly includes two semi-cylindrical covers having a connector at each end; a plurality of receiver rings for supporting the covers and engaging the connector; and an extender ring configured to move a first receiver ring toward a second receiver ring.

In one or more of the embodiments described herein, the assembly includes a base ring coupled to the extender ring.

In one or more of the embodiments described herein, the extender ring is rotatable relative to the base ring.

In one or more of the embodiments described herein, the extender ring is disposed between the base ring and the first receiver ring.

In one or more of the embodiments described herein, the first receiver ring is axially movable relative to the base ring.

In one or more of the embodiments described herein, the assembly includes a torque key coupled to the base ring and the first receiver ring.

In one or more of the embodiments described herein, the plurality of receiver rings include a slot for engaging the connector.

In one or more of the embodiments described herein, the connector is moved axially into engagement with the slot.

In one or more of the embodiments described herein, the covers cannot move radially relative to the plurality of receiver rings.

In one or more of the embodiments described herein, the connector comprises a plurality of pins.

In one or more of the embodiments described herein, the connector comprises a plurality of dovetails.

In one or more of the embodiments described herein, the shroud assembly encloses a device selected from the group consisting of a shunt tube, a wire, a cable, a coil, an electronic devices, and combinations thereof.

In some embodiments, a shroud assembly includes a plurality of receiver rings, each ring having two portions pivotally coupled to each other; two semi-cylindrical covers attached to the plurality of receiver rings; and a fastener for locking the two portions together.

In one or more of the embodiments described herein, the plurality of receiver rings include a flange for attaching the covers.

In one or more of the embodiments described herein, the flange is formed by attaching a flange ring to the plurality of receiver rings.

In one or more of the embodiments described herein, the flange is machined onto the plurality of receiver rings.

In one or more of the embodiments described herein, the plurality of receiver rings include an inner profile for accommodating a screen and a tube.

In one or more of the embodiments described herein, the assembly includes a base ring rotationally fixed relative to the plurality of receiver rings.

In some embodiments, a shunt tube assembly includes a plurality of joints of shunt tube, each of the joints include at least one nozzle, wherein a first joint located adjacent to a second joint has a different fluid outflow than the second joint.

In one or more of the embodiments described herein, the first joint and the second joint have a different number of nozzles.

In one or more of the embodiments described herein, three adjacent joints have a different number of nozzles.

In one or more of the embodiments described herein, the number of nozzles increases with respect to the joints in descending order.

In one or more of the embodiments described herein, a third joint located adjacent to the second joint has the same number of nozzles as the second joint.

In one or more of the embodiments described herein, a size of a nozzle of the first joint is different from a size of a nozzle of the second joint.

Claim 1:
A shroud assembly (<NUM>), comprising:
a plurality of receiver rings (<NUM>, <NUM>), each receiver ring having two portions pivotally coupled to each other;
two semi-cylindrical covers (<NUM>, <NUM>) attached to the plurality of receiver rings; and a fastener for locking the two portions together;
a base ring (<NUM>), a first receiver ring (<NUM>) of the plurality of receiver rings axially movable with respect to the base ring;
a torque key (<NUM>) coupled to the base ring and the first receiver ring, and
an extender ring (<NUM>) coupled to the base ring, and configured to move the first receiver ring toward a second receiver ring of the plurality of receiver rings, wherein the extender ring is rotatable relative to the base ring.