SYSTEM AND METHOD FOR CONTROLLING EROSION OF COMPONENTS DURING WELL TREATMENT

Abstract

A technique is provided for use in treating one or more well zones by directing a treatment fluid downwardly through a delivery tube and then outwardly through one or more nozzles into a desired well zone. The treatment fluid is delivered downhole to the desired well zone and at least a portion of that fluid is directed laterally outward from the well treatment completion through the one or more nozzles. Each nozzle comprises a material that protects both the nozzle and proximate portions of the delivery tube from detrimental erosion due to the passage of treatment fluid.

Description

BACKGROUND

Many types of well treatments are performed by a variety of completions. The well treatments may involve sand control operations in which gravel laden slurry is delivered downhole to a desired well zone to be gravel packed. In many applications, the gravel slurry can create significant erosion of completion components against which or through which the slurry is flowed to the desired well zone. In some gravel pack operations, the slurry is delivered down a tube, such as a shunt tube, and forced outwardly through laterally oriented nozzles. The flowing slurry can create component erosion at various contact points along the tube and nozzles. If the nozzles or tube become sufficiently eroded, the exiting slurry is not properly directed away from the completion components, e.g. sand screens, to create a properly functioning gravel pack.

Existing nozzles are generally constructed as a stainless steel tube, but rapidly flowing slurry can erode the stainless steel tube as well as the outlet opening of the delivery tube through which slurry flows to the nozzle. The erosion is currently minimized by pumping at slower rates to ensure gravel velocities are below the critical velocity causing erosion of the component. Attempts also have been made to minimize erosion by installing a carbide tube within the stainless steel tube. However, the carbide tube has not prevented erosion at the base of the nozzle and at the delivery tube wall proximate the nozzle entry. If the erosion leads to slurry bypassing the nozzle, the slurry is then no longer properly directed away from the completion, e.g. away from the filtration surface, which can result in erosion of the filtration surface and failure of the well completion.

SUMMARY

In general, the present invention provides a system and method for use with a completion in treating one or more well zones. The treatment involves directing a treatment fluid downwardly through a delivery tube and then outwardly through one or more nozzles into a desired well zone. A slurry or other treatment fluid is delivered downhole to the desired well zone and at least a portion of that fluid is directed laterally outward from the well treatment completion through the one or more nozzles. Each nozzle is uniquely designed to protect both the nozzle and proximate portions of the delivery tube from erosion that would detrimentally affect the well treatment operation.

BRIEF DESCRIPTION OF THE DRAWINGS

Certain embodiments of the invention will hereafter be described with reference to the accompanying drawings, wherein like reference numerals denote like elements, and:

FIG. 1 is a front elevation view of a completion assembly for use in a well treatment operation, according to an embodiment of the present invention;

FIG. 2 is a cross-sectional view of an embodiment of a nozzle coupled to a fluid delivery tubing, according to an embodiment of the present invention;

FIG. 3 is a cross-sectional view of another embodiment of a nozzle coupled to a fluid delivery tubing, according to an embodiment of the present invention;

FIG. 4 is a cross-sectional view of another embodiment of a nozzle coupled to a fluid delivery tubing, according to an embodiment of the present invention;

FIG. 5 is a cross-sectional view of another embodiment of a nozzle coupled to a fluid delivery tubing, according to an embodiment of the present invention;

FIG. 6 is a cross-sectional view of another embodiment of a nozzle coupled to a fluid delivery tubing, according to an embodiment of the present invention;

FIG. 7 is a cross-sectional view of another embodiment of a nozzle coupled to a fluid delivery tubing, according to an embodiment of the present invention;

FIG. 8 is a cross-sectional view of another embodiment of a nozzle coupled to a fluid delivery tubing, according to an embodiment of the present invention;

FIG. 9 is a cross-sectional view of another embodiment of a nozzle having an insert plate coupled to a fluid delivery tubing, according to an embodiment of the present invention;

FIG. 10 is a cross-sectional view of another embodiment of a nozzle having an insert plate coupled to a fluid delivery tubing, according to an embodiment of the present invention;

FIG. 11 is a cross-sectional view of another embodiment of a nozzle coupled to a fluid delivery tubing, according to an embodiment of the present invention;

FIG. 12 is a cross-sectional view of another embodiment of a nozzle coupled to a fluid delivery tubing, according to an embodiment of the present invention;

FIG. 13 is a cross-sectional view of another embodiment of a nozzle coupled to an interior surface of a fluid delivery tubing, according to an embodiment of the present invention;

FIG. 14 is a cross-sectional view of another embodiment of a nozzle coupled to a fluid delivery tubing, according to an embodiment of the present invention;

FIG. 15 is a cross-sectional view of another embodiment of a nozzle coupled to a fluid delivery tubing, according to an embodiment of the present invention;

FIG. 16 is a cross-sectional view of another embodiment of a nozzle coupled to a fluid delivery tubing, according to an embodiment of the present invention;

FIG. 17 is a cross-sectional view of another embodiment of a nozzle coupled to a fluid delivery tubing, according to an embodiment of the present invention;

FIG. 18 is a cross-sectional view of another embodiment of a nozzle coupled to a fluid delivery tubing, according to an embodiment of the present invention;

FIG. 19 is a cross-sectional view of another embodiment of a nozzle coupled to a fluid delivery tubing, according to an embodiment of the present invention; and

FIG. 20 is a cross-sectional view of another embodiment of a nozzle coupled to a fluid delivery tubing, according to an embodiment of the present invention.

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 of ordinary skill 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.

The present invention generally relates to a well system that can be used for well treatment operations, such as sand control operations. The well system is designed to deliver a well treatment fluid, e.g. a gravel slurry, downhole to a desired well zone. The well treatment fluid is delivered through a tubing, such as a shunt tube, and then routed laterally outward through one or more nozzles. Each nozzle comprises an insert region that forms a flow path for the well treatment fluid. The insert region is designed to control erosion with respect to both the nozzle and the tubing portion proximate the nozzle.

Referring generally to FIG. 1, one embodiment of a well system 30 is illustrated. In this embodiment, well system 30 comprises a completion assembly 32 deployed in a wellbore 34. The wellbore 34 is drilled into a subsurface formation 36 having at least one well zone 38 to be treated, e.g. gravel packed. Wellbore 34 extends downwardly from a surface location 40, such as a surface of the earth or a subsea surface location.

Completion assembly 32 comprises a treatment string 42 that can be used to perform the treatment of well zone 38. A well treatment fluid is delivered downhole through completion assembly 32 and along treatment string 42 via one or more delivery tubes or tubular members 44. The treatment fluid is directed radially or laterally outward from tubular members 44 via one or more nozzles 46. In the example illustrated, tubular members 44 comprise one or more shunt tubes 48 that route the treatment fluid along treatment string 42. If the well treatment is a sand control treatment, e.g. a gravel packing treatment, treatment string 42 comprises one or more screens 50, and the treatment fluid comprises a gravel slurry, as known to those of ordinary skill in the art. Also, one or more well zones 38 can be isolated by appropriately placed packers 52.

Nozzles 46 are designed to redirect the well treatment fluid flowing through the tubular members 44 and ordinarily are susceptible to wear, particularly with abrasive treatment fluids such as gravel slurry. Several embodiments of nozzles 46 that are designed to eliminate or at least control erosion caused by the treatment fluid are described herein. One embodiment is illustrated in FIG. 2 as mounted to one of the tubular members 44, e.g. shunt tube 48, that deliver a well treatment fluid downhole, as indicated by arrows 54. At least a portion of the well treatment fluid is redirected laterally outward through the nozzle 46.

In this embodiment, nozzle 46 comprises an insert region 56 having a flow passage 58 through which the well treatment fluid flows laterally outward from an interior 60 of tubular member 44. Insert region 56 is formed from an erosion resistant material which may be a hardened material, such as a carbide material. For example, the insert region 56 can be formed of tungsten carbide, a ceramic material, or Stellite. The outward flow of well treatment fluid is enabled by an opening 62 formed through a wall 64 of tubular member 44. Insert region 56 comprises a corresponding end region 66 sized to fit within opening 62 and extend through wall 64. By extending the material of insert region 56 through wall 64, protection is provided both for nozzle 46 and for tubular member 44 in the region where well treatment fluid is routed into nozzle 46. In the embodiment illustrated, insert region 56 extends into opening 62 until it is generally flush with an interior surface 68 of tubular member 44.

As illustrated, insert region 56 further comprises a shoulder 70 positioned to abut a wall 64 and prevent the insert region 56 from moving inwardly into tubular member 44. A retaining housing 72 is positioned over insert region 56 on the exterior side of tubular member 44 to secure insert region 56 and the overall nozzle 46 with respect to tubular member 44. By way of example, retaining housing 72 may be formed from a conventional nozzle material, such as a steel material, that is welded or otherwise fastened to wall 64 of tubular member 44. In this embodiment, retaining housing 72 comprises an opening 74 through which the well treatment fluid is discharged from flow passage 58. It should be noted the insert region 56 can be formed as a separable component or as a component adhered to or otherwise combined with retaining housing 72. The insert region 56 also can be coated onto or otherwise applied to retaining housing 72.

Another embodiment of nozzle 46 is illustrated in FIG. 3. In this embodiment, the components are similar to the components described with reference to FIG. 2, except that corresponding end region 66 extends inwardly beyond a flush position with interior surface 68 and into the interior 60 of tubular member 44. By extending the insert region 56 into interior 60, the nozzle 46 is able to “grab” well treatment fluid passing through tubular member 44 and redirect the fluid into nozzle 46. By extending the erosion resistant material of insert region 56 into interior 60, both nozzle 46 and tubular member 44 proximate opening 62 are protected from material erosion.

The configuration of insert region 56 can be adjusted to combat material erosion in areas experiencing the greatest susceptibility to erosion and loading. As illustrated in FIG. 4, for example, insert region 56 is formed eccentrically such that a lower wall portion 76 of corresponding end region 66 is thicker, at least where it extends into interior 60. The thicker erosion resistant material is located on the side experiencing the greatest potential for erosion and loading with this particular nozzle configuration.

In another embodiment, insert region 56 comprises a laterally outward end 78 sized to extend through opening 74 of retaining housing 72. The outward end 78 of insert region 56 further protects retaining housing 72 from erosion at the point where well treatment fluid is discharged from nozzle 46. This type of laterally outward end 78 can be utilized with a number of the nozzle embodiments described herein. For example, positioning outward end 78 through housing opening 74 can be utilized with a nozzle insert region having a concentric (as opposed to eccentric) corresponding end region 66, as illustrated best in FIG. 6.

An alternative approach to controlling erosion that may occur at the nozzle tip is illustrated in the embodiment of FIG. 7. In this embodiment, outward end 78 does not extend through housing opening 74; however the insert region 56 is blocked from moving outwardly with respect to retaining housing 72 by an outer shoulder 80. Outer shoulder 80 is formed in insert region 56 to abut a corresponding shoulder 82 of retaining housing 72. Thus, even if retaining housing 72 erodes at opening 74, outer shoulder 80 prevents the outward movement of insert region 56.

Insert region 56 also can be retained within retaining housing 72 by fastening insert region 56 to an interior of retaining housing 72 by an appropriate fastening mechanism 84, as illustrated in FIG. 8. Examples of fastening mechanism 84 comprise an adhesive, threads, a weldment, a brazed joint, a press fit or another suitable mechanism for a fixing insert region 56 to the surrounding retaining housing 72. This enables the construction of retaining housing 72 in a simple form, such as the illustrated tubular housing. Fastening mechanism 84 also enables the creation of a variety of nozzle outlets 86 with the erosion resistant material of insert region 56.

In some applications, further protection of tubular member 44 from erosion can be provided by forming insert region 56 has a two-part member, as illustrated in FIG. 9. The two-part insert region 56 comprises a housing portion 88 within retaining housing 72 and a plate portion 90 that replaces a portion of wall 64 of tubular member 44. The two-part insert can be formed as completely separate components or as attached or combined components. In the embodiment illustrated, plate 90 is naturally held in place by the tube walls on the interior side and by a retaining housing plate 92 on the exterior side. Housing plate 92 can be attached and sealed to wall 64 by welding or other appropriate permanent attachment mechanisms. Plate 90 comprises an opening 94 that forms the initial portion of flow passage 58 through which well treatment fluids flow. In this embodiment, housing portion 88 is formed as a simple hollow shaft trapped within retaining housing 72.

A similar embodiment is illustrated in FIG. 10. In the embodiment of FIG. 10, plate 90 is a circumferential plate that extends around the circumference of tubular member 44, effectively separating tubular member 44 into an upper section 96 and a lower section 98. Retaining housing plate 92 also extends circumferentially around tubular member 44 in a manner that holds circumferential plate 90 in place between tubular sections 96 and 98. This style of plate 90 provides erosion protection across the entire tubular member in the vicinity of nozzle 46.

Another embodiment of nozzle 46 is illustrated in FIG. 11. In this embodiment, the insert region 56 comprises an enlarged block 100 having flow passage 58 therethrough. The corresponding section of tube wall 64 is removed to accommodate enlarged block 100 which extends through wall 64 at least to a point where the block is substantially flush with interior surface 68 of tubular member 44. The enlarged block 100 can be secured within wall 64 by an appropriate adhesive, weldment or other suitable fastener. Because of the enlarged size of block 100, the block may be designed to undergo a controlled erosion in which the gravel pack or other well treatment is completed before a critical amount of the nozzle material is eroded. Accordingly, this type of nozzle 46 can be made from a cheaper material due to the ability to allow the controlled erosion. For example, controlled erosion can be achieved with a steel material, e.g. stainless steel, a plastic material, or other suitable materials that enable the controlled erosion.

As illustrated in FIG. 12, enlarged block 100 also may be attached to the exterior of tubular member 44 by a suitable attachment mechanism, e.g. weldment, adhesive, brazing, or other suitable fastener. In this embodiment, tubular wall opening 62 is protected by the size of block 100. In other words, even though the wall of tubular member 44 may erode, the erosion does not expand beyond block 100 prior to completion of the gravel pack or other well treatment. Effectively, the size and position of enlarged block 100 of nozzle 46 controls the erosion and eliminates or reduces the potential to create unwanted openings through which the slurry or other treatment fluid can flow.

In another alternate embodiment, insert region 56 is retained from moving away from tubular member 44 by an internal flange 102 positioned along interior surface 68 of tubular member 44, as illustrated in FIG. 13. This same insert region 56 can be prevented from moving inwardly into tubular member 44 by a retaining housing or other suitable fastening mechanism. Examples of fastening methods comprise adhering, welding, brazing, and the use of external threads and a retaining nut.

Other embodiments of nozzle 46 are designed to control the flow of slurry or other treatment fluid as it exits the nozzle, as illustrated in FIGS. 14 and 15. For example, the shape and size of flow passage 58 can be adjusted to change the velocity of the particles within the treatment fluid. In the embodiment illustrated in FIG. 14, for example, the flow passage 58 is designed to slow particle velocities exiting nozzle 46 to reduce the likelihood of eroding the filter or other hardware in the vicinity of nozzle 46. As illustrated, the height of flow passage 58 increases as the flow passage transitions from an inlet 104 to an exit 106. In this particular example, the width of flow passage 58 is substantially constant, however other flow passage designs can be utilized to further control the flow of treatment fluid. Furthermore, the expanding flow passage 58 is illustrated as formed in the enlarged block 100 positioned either through wall 64 (FIG. 14) or attached along the exterior of wall 64 (FIG. 15). However, the configuration of flow passage 58 can be changed to achieve desired flow characteristics for the other embodiments of nozzle 46.

In some applications, nozzle 46 can be constructed by forming insert region 56 as a simple tube 108 inserted in through opening 62 of wall 64 and into interior 16 of tubular member 44, as illustrated in FIG. 16. Again, this simple type of insert protects both nozzle 46 and tube wall 64 from erosion, because the erosion resistant insert region extends through the tubular member wall. The nozzle tube 108 can be attached to tubular member 44 by a suitable fastening method, including adhering, press fitting, threading, welding and brazing. Additionally, the flow passage 58 can be routed in a generally linear direction, as illustrated in FIG. 16, or along a curvilinear path, as illustrated in FIG. 17. Curvilinear flow paths also can be incorporated into other embodiments of nozzle 46.

Nozzles 46 also can be designed to change their spray pattern over time, as illustrated by the embodiments of FIGS. 18 and 19. The design and material of the nozzle is selected to undergo a controlled erosion having no deleterious effects on the nozzle or the tubular member 44 that would interfere with the desired well treatment. In the embodiment illustrated in FIG. 18, nozzle 46 is attached to an exterior of tubular member 44 over opening 62 via a suitable fastening method, e.g. adhering, welding, brazing. The flow passage 58 is generally arcuate, curving downwardly via an outer lip 110. Initially, the gravel slurry or other treatment fluid is sprayed in a downward direction. However, as lip 110 erodes in a desired, controlled manner, the angle of spray fans upwardly and outwardly to provide a better fill from the bottom up. In many applications, lip 110 is designed so the spray angle does not move upwardly beyond a desired angle, e.g. 45°.

The use of a nozzle that undergoes controlled erosion to selectively change the spray pattern can be incorporated with a number of the nozzle embodiments described herein. Another example is illustrated in FIG. 19, in which the nozzle 46 comprises an end region 112 sized to fit within wall opening 62. The end region 112 can be designed to extend to a location flush with interior surface 68 or to extend further into the interior 60 of tubular member 44.

Another embodiment of nozzle 46 incorporates a spacer ring 114, as illustrated in FIG. 20. The spacer ring 114 allows the hardened material of insert region 56 to be formed with a generally perpendicular shoulder 116. Perpendicular shoulder 116 is arranged to abut spacer ring 114 at an outlying end, while the opposite end of spacer ring 114 abuts the wall 64 of tubular member 44. Thus, shoulder 116 and spacer ring 114 prevent insert region 56 from moving inwardly into tubular member 44. Retaining housing 72 is positioned over both insert region 56 and spacer ring 114. In the embodiment illustrated, insert region 56 further comprises a reduced diameter section 118 that fits within spacer ring 114. The flow passage 58 extends generally axially through the reduced diameter section 118 and past shoulder 114 until it meets opening 74 of retaining housing 72.

The unique nozzles 46 can be used with a variety of completion assemblies and service tools where it is necessary or desirable to control or eliminate erosion that would otherwise be caused by the well treatment fluid. Furthermore, the nozzles can be used in many sand control/gravel packing operations practiced in a variety of environments. However, the nozzles also can be used in other treatment operations. The size, shape and location of each nozzle 46 can be adjusted according to the needs of a specific well treatment operation. Similarly, the materials used to form each nozzle 46 can be selected according to the environment, the type of well treatment fluid, the desire to eliminate or otherwise control the erosive effects of the well treatment fluid, and other operational parameters. The shunt tubes or other fluid delivery tubes also can be designed and routed according to the treatment operation and the treatment equipment used in the operation.

Accordingly, although only a few embodiments of the present invention have been described in detail above, those of ordinary skill in the art will readily appreciate that many modifications are possible without materially departing from the teachings of this invention. Such modifications are intended to be included within the scope of this invention as defined in the claims.

Claims

1. A system to facilitate a gravel packing operation, comprising:

a shunt tube through which a gravel slurry is directed; and

a nozzle coupled to the shunt tube to direct a portion of the gravel slurry laterally outward from the shunt tube, the nozzle having a hardened insert region forming a flow path and extending through a wall of the shunt tube.

2. The system as recited in claim 1, wherein the hardened insert region extends through the wall until it is flush with the inside diameter of the shunt tube.

3. The system as recited in claim 1, wherein the hardened insert region extends through the wall and into an interior of the shunt tube.

4. The system as recited in claim 1, wherein the nozzle further comprises a retaining housing to hold the hardened insert region against the wall of the shunt tube.

5. The system as recited in claim 4, wherein the hardened insert region comprises a shoulder positioned to prevent movement of the hardened insert region into the shunt tube.

6. (canceled)

7. The system as recited in claim 1, wherein the hardened insert region is secured directly to the wall of the shunt tube.

8. The system as recited in claim 1, wherein the hardened insert region comprises a separate plate positioned in a corresponding opening formed in the wall, of the shunt tube.

9. (canceled)

10. The system as recited in claim 1, wherein the hardened insert region is retained with respect to the shunt tube from an interior of the shunt tube.

11. The system as recited in claim 1, wherein the flow path within the nozzle is curvilinear.

12. A method to facilitate a well treatment, comprising:

flowing a slurry into a wellbore region through a delivery tube;

diverting at least a portion of the slurry laterally through a nozzle; and

protecting both the nozzle and the delivery tube from erosion with an insert located along a flow path into and through the nozzle.

13. The method as recited in claim 12, wherein protecting comprises extending the insert through a wall of the delivery tube and into an interior of the delivery tube.

14. The method as recited in claim 12, wherein protecting comprises extending the insert until the insert is generally flush with a wall surface defining an internal diameter of the delivery tube.

15. The method as recited in claim 12, further comprising holding the insert at a desired position with a retaining housing.

16. (canceled)

17. (canceled)

18. The method as recited in claim 12, further comprising securing the nozzle to an interior surface of the delivery tube.

19. The method as recited in claim 12, further comprising securing the nozzle at an opening formed through the delivery tube.

20. The method as recited in claim 12, wherein protecting comprises forming a portion of the insert as a plate fitted within an opening formed in the delivery tube.

21. The method as recited in claim 12, further comprising forming the nozzle to erode in a predetermined manner.

22. The method as recited in claim 12, further comprising providing the nozzle with a curvilinear flow path.

23. A method, comprising:

forming a nozzle with a material that limits the normal erosion otherwise incurred during passage of a gravel slurry through the nozzle; and

fastening the nozzle over a side opening of a tubular member through which the gravel slurry is delivered such that the material also protects the tubular member from erosion proximate the side opening.

24. The method as recited in claim 23, wherein forming comprises forming the nozzle with a retaining housing and an insert held at least partially within the retaining housing, the insert being formed of the material.

25. The method as recited in claim 23, wherein forming comprises forming the nozzle to extend through the side opening and to protrude into an interior of the tubular member.

26. The method as recited in claim 23, wherein forming comprises forming the nozzle with a separate plate sized to fit within the side opening.

27. A system, comprising:

a nozzle for use in directing an erosive fluid from a delivery tube and into a wellbore region, the nozzle having an insert formed of a material to control erosion of both the nozzle and the delivery tube, the insert being positioned to extend through a wall of the delivery tube to at least an inside diameter of the delivery tube upon attachment of the nozzle to the delivery tube.

28. The system as recited in claim 27, wherein the nozzle comprises a retaining housing surrounding the insert.

29. The system as recited in claim 27, wherein the nozzle is formed from a material that erodes in a controlled manner to change a nozzle spray pattern.