Multiple Port Crossover Tool with Port Selection Feature

Abstract

A crossover for gravel packing has multiple outlets that are selectively covered as they wear from erosion with the covering of an outlet exposing another for slurry flow to continue. Outlets are selected by a series of balls that get larger and land on progressively higher and larger seats on sleeves. As a sleeve shifts to cover a spent outlet it moves away from a new outlet for continuation of slurry flow to the outlet opened by virtue of the shifting sleeve.

Description

FIELD OF THE INVENTION

The field of the invention is subterranean tools that experience severe erosion from slurry flow through ports and more particularly a selection feature that allows selection of other ports when other ports become unserviceable.

BACKGROUND OF THE INVENTION

Completion operations in subterranean wells frequently involve deposition of gravel slurries outside a series of screens through a tool known as a crossover. This tool allows the slurry to be pumped down the tubing and past an isolation packer and out into a lower annulus that is outside the screens. The gravel fills the lower annulus and the fluid goes through the screens and into a wash pipe and back into a different flow path of the crossover tool for the trip to the surface in the upper annulus. The lower annulus is formed by a casing string or could simply be in open hole. The gravel slurry generally goes through a first port and into an intermediate annulus and then travels a little further downhole before making an exit out of the tool and into the lower annulus. The port where the slurry makes the first turn generally sees the most erosion effects. The typical flow pattern is illustrated in U.S. Pat. No. 7,559,357 which also shows the use of deflector plates to reduce the erosion effects of the gravel slurry upon exit from the crossover in to the lower cased annulus.

One attempt to minimize erosion, primarily in an injection well that involves high velocity flow of fluids such as steam is U.S. Pat. No. 7,419,003. Here the focus was on the shape of the ports as a way to reduce edge erosion. Another attempt in a crossover was to simply provide a plurality of spaced ports that were also circumferentially offset to get better gravel deposition in the lower annulus with the hope that multiple ports to take the flow would reduce the velocity at each port to the point where erosion would be minimized. This scheme is illustrated in U.S. Pat. No. 7,503,384. Yet another injection application that involved ported sliding sleeves with some focus on the port shape was reported in a paper from the American Association of Drilling Engineers 03-NTCE-18 (2003) pages 1-15. This report was also discussed in more detail in the background discussion in U.S. Pat. No. 7,419,003.

What is needed and not addressed in the art is a scheme where multiple outlets can be provided where erosion is an issue and selected as needed when an outlet has experienced erosion or after a predetermined volume of flow. As an added feature an outlet that is no longer in use can be covered over and preferably as another outlet is made accessible. These and other advantages of the present invention will be more apparent to those skilled in the art from a review of the detailed description of the preferred embodiment and the associated drawings while recognizing that the full scope of the invention is determined by the appended claims.

SUMMARY OF THE INVENTION

A crossover for gravel packing has multiple outlets that are selectively covered as they wear from erosion with the covering of an outlet exposing another for slurry flow to continue. Outlets are selected by a series of balls that get larger and land on progressively higher and larger seats on sleeves. As a sleeve shifts to cover a spent outlet it moves away from a new outlet for continuation of slurry flow to the outlet opened by virtue of the shifting sleeve.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a half section view through a crossover with an initial port open;

FIG. 2 is the view of FIG. 1 with the initial port covered and a second port exposed;

FIG. 3 is the view of FIG. 2 with the second port covered and a third port exposed.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

The crossover tool itself is well known to those skilled in the art and only a portion of it that is modified is shown to illustrate the invention. The gravel slurry generally enters the tubing string connected to the crossover tool body 10 that has a passage 12 running through it. Unlike many prior designs that have a single outlet from a passage such as 12 the present invention features a plurality of outlets with four being illustrated as an example although more or fewer outlets can be used. The outlets are 14, 16, 18 and 20. Arrow 22 indicates that initial slurry flow is through the open port 14. Sliding sleeves 24, 26 and 28 are shown in FIG. 1 to respectively cover ports 16, 18 and 20. Sliding sleeves 24, 26 and 28 have ball seats 30, 32 and 34 that are sized to take progressively larger balls in view of their progressively decreasing radial extension.

After a predetermined volume of slurry flow has been pumped through open port 14 as shown in FIG. 1 a ball 36 is dropped and/or pumped to seat 30 having bypassed the upper seats 32 and 34 that are far larger than ball 36. Pressure applied onto ball 36 while seated on seat 30 of sleeve 24 results in shifting the sleeve 24 to expose port 16 and close port 14. Flow continues to port 16 as indicated by arrow 38. The process can be repeated with ball 40 landing on seat 32 to move sleeve 26 down to cover port 16 while exposing port 18. Arrow 42 indicates the flow going to port 18. The process can be repeated with an even larger ball landing on seat 34 to close port 18 and open port 20.

There are variations that are contemplated. The ports 14 through 20 can be axially aligned or they can be offset. The sleeves 24 through 28 can be solid as shown or they can be ported. In that case, for example, instead of sleeve 24 coming off of port 16 when closing port 14, sleeve 24 can be longer with a port in it so that the port in sleeve 24 overlaps port 16 while covering port 14 at the same time as a result of being shifted with ball 36 on it. The other sleeves can work in the same way although the solid sleeve option is preferred. The balls that get dropped just stay in the tool and when the gravel packing is complete and the crossover tool comes out the balls can be removed at that time at the surface. The openings can be the same size and shape or they can be varied in size and shape. The length of time that each port is in service can be determined by run time of slurry pumping or by measured slurry volume pumped or by monitoring the pressure required to maintain a flow or even by instruments that monitor pressure drop through each opening or some other variable that indirectly indicates wear on a given port. Another less desirable option is to associate two sleeves with each port where one is shifted to open the port and another is then shifted to close the same port. This requires almost twice the sleeves as the layout shown in FIGS. 1-3 and could be logistically complicated to execute in the smaller sizes if using the technique of progressively larger balls. Although balls are preferred, other object shapes that can land on a seat on a sleeve so as to allow applied pressure to shift the sleeve are also contemplated.

While flow through sleeves 24 to 28 occurs during slurry flow to port 14 which can cause some erosion on the seats 30 to 34 it is anticipated that even if there is some erosion that a respective ball that lands on any of those seats should still be capable of holding back pressure so that the sleeve in question can be shifted. Alternatively the sleeves can be shifted by a motor associated with each sleeve to move it between two end positions and such movement can be controlled at the surface. As another option a given sleeve can cover more than a single port while uncovering more than a single port. The ports covered or uncovered can be axially aligned while circumferentially spaced or they may be axially spaced while circumferentially aligned or misaligned. As another option the sleeves can have a locking feature that holds them in the shifted position such as by a snap ring that snaps into a groove when the travel limit of a given sleeve is reached. The seats can be made of a hardened material or have a coating of a material that resists erosion so that they will maintain sealing integrity with an object dropped on them after slurry flow has passed through them for a time.

The above description is illustrative of the preferred embodiment and many modifications may be made by those skilled in the art without departing from the invention whose scope is to be determined from the literal and equivalent scope of the claims below.

Claims

1. A flow diversion assembly for a ported subterranean tool inserted from a surface, comprising:

a housing having a passage therein and at least a first and a second port for exit of flow from said passage;

at least one valve member in said passage selectively covering one of said first and second ports.

2. The assembly of claim 1, wherein:

said valve member movable from a first position where said first port is uncovered and said second port is covered to a second position where said first port is covered and said second port is uncovered.

3. The assembly of claim 2, wherein:

said valve member moves in a single axial direction.

4. The assembly of claim 2, wherein:

said valve member comprises a seat that accepts an object to close off a path through said valve member to allow pressure applied to said object on said seat to move said valve member.

5. The assembly of claim 2, wherein:

said valve member comprises a sleeve having a sleeve passage therethrough defined by a wall that has no wall openings.

6. The assembly of claim 2, wherein:

said valve member locks to said housing in said second position.

7. The assembly of claim 2, wherein:

said first and second ports comprise a plurality of ports at least two said ports being axially spaced.

8. The assembly of claim 7, wherein:

at least two said ports are axially spaced and aligned.

9. The assembly of claim 7, wherein:

at least two said ports are located side by side and circumferentially spaced.

10. The assembly of claim 7, wherein:

said at least one valve member comprises a plurality of valve members.

11. The assembly of claim 10, wherein:

there are one fewer valve members than the number of said ports.

12. The assembly of claim 10, wherein:

said valve members each comprise a seat that accepts an object to close off a path through said valve member to allow pressure applied to said object on said seat to move said valve member;

said valve members are disposed adjacent said ports with said seat associated with said valve member closest to the surface having the largest seat with said seat size declining in other valve members in a direction away from the surface.

13. The assembly of claim 12, wherein:

said lowermost port furthest from the surface is initially open;

said ports are serially opened by sequential movement of said valve members by sequential landing of objects of increasing size on seats of valve members in a direction toward the surface.

14. The assembly of claim 13, wherein:

said ports are sequentially closed starting with said lowermost port by sequential movement of said valve members by sequential landing of objects of increasing size on seats of valve members in a direction toward the surface.

15. The assembly of claim 14, wherein:

shifting of one valve member opens or closes more than one port.

16. The assembly of claim 14, wherein:

said valve members each comprise a sleeve having a sleeve passage therethrough defined by a wall that has no wall openings.

17. The assembly of claim 14, wherein:

said valve members each comprise a sleeve having a sleeve passage therethrough defined by a wall that has at least one wall opening that is aligned with a port in one of said first and said second positions of said valve member.

18. The assembly of claim 14, wherein:

said seats comprise a tapered annular surface;

said objects comprise spheres.

19. The assembly of claim 18, wherein:

said spheres are retained on respective seats for subsequent removal to the surface with said housing.

20. The assembly of claim 14, wherein:

said ports are aligned and axially spaced.