MODULAR DART LAUNCHER WITH STATUS INDICATOR
A dart launcher launches a dart by placing the dart within a launcher bore formed within a launcher body. The launcher body also defines a central bore coupled inline with a tubing string and in fluid communication with the launcher bore. The launcher bore is formed at an angle to the central bore. A release assembly is coupled to the launcher body and includes a release rod protruding into the launcher bore to selectively release the dart. A visual indicator assembly is coupled to the launcher body downstream from the release assembly and includes a flapper protruding into the launcher bore. The release assembly is actuated by the dart rotating the flapper to rotate an arm from a non-released position to a released position.
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1. Field of the Invention
This invention relates in general to drop balls, plugs, or darts used to operate well tool functions and, in particular, to a drop ball, plug, or dart launcher with a status indicator.
2. Brief Description of Related Art
Standard dart or ball launchers have a member that defines a central bore that may be coupled inline with a drill or tubing string. The launchers also include an angular bore that intersects the central bore at a shallow angle between the angular bore and the central bore. A dart or ball is dropped into the angular bore, and after opening a series of valves, the ball or dart is introduced into the central bore for further movement of the dart or ball down the borehole. There, the dart or ball will land at a predetermined location to block the borehole and allow hydraulic tool operations. In order to minimize the potential that the ball will snag or hang up as it moves from the angular bore to the central bore, the angle of the intersection between the two axes is as close to zero degrees as possible. This necessitates that the launcher must be very tall to smooth out the transition between the angular bore and the central bore. The height can make the launcher very difficult to access and operate.
Other devices couple inline with the drill or tubing string and use a series of valves to launch the ball or dart. The dart or ball may become stuck or snagged at the valve openings, preventing successful release of the dart or drop ball. In addition, these types of devices require bypass passages within the valves so that fluids may flow around the darts and valves prior to launching the dart or ball. These passages restrict fluid flow through the running string and may become clogged. Clogging of these passages will, in turn, require stoppage of drilling operations in order to remove and reset the launcher for operation. Even when not blocked, these passages may restrict the flow of fluid downhole, causing further complications in drilling operations.
Still other devices may couple inline with the drill or tubing string and use a series of balls to launch darts or plugs contained within the device. These devices rely on complex landing and sliding sleeve devices, to bypass the fluids around the landed balls and darts, again restricting fluid flow through the string. These devices also do not provide an indication that the proper dart or plug has been launched following landing of the ball.
Generally, following launch of a ball, dart, or plug, operators wait for an increase in pressure within the tubing string to indicate that the ball, dart, or plug has properly released into the drill string and landed at the ball, dart, or plug seat. Operators may then proceed with operations such as cementing or running tool actuation. However, in some wells, particularly in deep subsea wells, the distances between the operating platform and the landing location are large enough that it may take over an hour for the dart to land at the seat. As a result, operators may proceed with operations following release of the ball, dart, or plug but before they have received any indication that the ball, dart, or plug has landed. In the event that the ball, dart, or plug becomes hung up or snagged in the launcher and does not release into the tubing string, the well may be significantly damaged, necessitating expensive and time consuming repair operations. Some launchers include an electrical system for indicating that the dart, ball, or plug has released, however these systems require complex components that are prone to failure and difficult to adapt to changing types and sizes of balls, darts, and plugs. Thus, there is a need for a launcher that launches the dart or ball from an inline coupling without restricting fluid flow through the central bore of the tubing and that may provide an indication of a successful launch of the ball, dart, or plug.
SUMMARY OF THE INVENTIONThese and other problems are generally solved or circumvented, and technical advantages are generally achieved, by preferred embodiments of the present invention that provide a modular dart launcher with a status indicator and a method for using the same.
In accordance with an embodiment of the present invention, a wellbore drop member launcher is disclosed. The launcher includes a launcher body defining a central bore having a central bore axis, the launcher body having a lower end configured to attach to a string of pipe extending into a wellbore. The launcher body also defines a launcher bore having a launcher bore axis at an angle to the central bore axis, the launcher bore in fluid communication with the central bore. A release assembly is coupled to the launcher body and has a release rod protruding into the launcher bore to prevent movement of a drop member positioned within the launcher bore in a drop member hold position. The release assembly is configured to move the release rod to a drop member release position to selectively release the drop member positioned within the launcher bore. A visual indicator assembly is, coupled to the launcher body and is configured to provide a mechanically produced visual indication that the drop member has moved from the launcher bore to the central bore.
In accordance with another embodiment of the present invention, a wellbore drop member launcher is disclosed. The launcher includes a launcher body defining a central bore having a central bore axis, the launcher body having a lower end configured to attach to a tubing string extending into a wellbore. The launcher body also defines a launcher bore having a launcher bore axis at an angle to the central bore axis. The launcher bore is in fluid communication with the central bore. A release assembly is coupled to the launcher body and has a release rod protruding into the launcher bore to prevent movement of a drop member positioned within the launcher bore into the tubing string. The release assembly is configured to move the release rod with a piston assembly from a drop member hold position to a drop member release position to selectively release the drop member. The piston assembly also biases the release rod to the drop member hold position. A pressure passage is defined by the release rod and is configured to equalize pressure between a compressible portion of the piston assembly and the launcher body, preventing premature drop member release. The pressure passage extends from an end of the release rod disposed within the launcher bore through a center of the release rod to an annular chamber within the piston assembly. An indicator housing is coupled to the launcher body proximate to an indicator bore that is defined by the launcher body and extends from an exterior of the launcher body to the launcher bore. An indicator rod extends through the indicator housing into the indicator bore. The indicator rod has a flapper formed near an end of the indicator rod and an arm secured to an opposite end of the indicator rod. The flapper and the arm are perpendicular to the indicator rod and parallel to each other. The flapper extends from the indicator bore into the launcher bore and the arm is visible to an operator. As the drop member passes the flapper it will rotate the flapper, indicator rod, and arm to indicate release of the drop member.
In accordance with yet another embodiment of the present invention, a method for launching a drop member into a wellbore tubing string is disclosed. The method provides a launcher body having a central bore with a central bore axis and a launcher bore with a launcher bore axis at an angle to the central bore axis and in fluid communication with the central bore. The method places a drop member in the launcher bore and resting the drop member on a release rod of a release assembly coupled to the launcher body. The method couples a visual indicator assembly to the launcher body so that the visual indicator assembly is in communication with the launcher bore at a location downstream from the release assembly. The method couples the launcher body in line with the tubing string so that the central bore of the launcher body aligns with a body passage through the tubing string. The method then actuates the release assembly to allow the drop member to flow from the launcher body into the central bore where the drop member may move down the tubing string. The method actuates the visual indicator assembly with the drop member as the drop member moves from the launcher bore into the central bore.
An advantage of a preferred embodiment is that it provides a dart launcher that may be used in high fluid pressures situations. In addition, the disclosed embodiments provide an apparatus and method to easily launch a ball, dart, or plug with minimal human intervention. Still further, the disclosed embodiments provide a modular apparatus that allows for variation in the size of the ball, dart, or plug launched. Sill further, the disclosed embodiment provides a visual indicator for an operator to confirm the successful launch of the ball, dart, or plug that does not rely on complicated electronics systems that may be prone to failure in harsh operating environments.
So that the manner in which the features, advantages and objects of the invention, as well as others which will become apparent, are attained, and can be understood in more detail, more particular description of the invention briefly summarized above may be had by reference to the embodiments thereof which are illustrated in the appended drawings that form a part of this specification. It is to be noted, however, that the drawings illustrate only a preferred embodiment of the invention and are therefore not to be considered limiting of its scope as the invention may admit to other equally effective embodiments.
The present invention will now be described more fully hereinafter with reference to the accompanying drawings which illustrate embodiments of the invention. This invention may, however, be embodied in many different forms and should not be construed as limited to the illustrated embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. Like numbers refer to like elements throughout, and the prime notation, if used, indicates similar elements in alternative embodiments or positions.
In the following discussion, numerous specific details are set forth to provide a thorough understanding of the present invention. However, it will be obvious to those skilled in the art that the present invention may be practiced without such specific details. Additionally, for the most part, details concerning drilling rig operation, well tool manufacture, well tool operation, well tool uses, and the like have been omitted inasmuch as such details are not considered necessary to obtain a complete understanding of the present invention, and are considered to be within the skills of persons skilled in the relevant art.
Referring to
Dart launcher 11 also includes a launcher body 17, a dart release assembly 19, and a visual indicator assembly 21. Top pup 13 and bottom pup 15 may secure to or couple to launcher body 17 on opposite ends of launcher body 17 so that top pup 13 and bottom pup 15 are coaxial with an axis 23 of a central bore 25 of launcher body 17 (
Referring to
Referring to
A shaft of piston 41 passes through a spring 51 disposed within actuator bore 43. An end of the shaft of piston 41 will couple to a spring perch 53 disposed within actuator bore 43 opposite pressure chamber 39 in the dart hold position. Spring perch 53 may move through actuator bore 43 with piston 41 in response to application of pressure to pressure chamber 39. Spring 51 will be positioned to bias spring perch 51 to the dart hold position of
Release housing 37 defines actuator bore 43 and a rod bore 59. Rod bore 59 and actuator bore 43 are separated by a chamber wall 61 having a port for communication between actuator bore 43 and rod bore 59. Spring perch 53 may include a protrusion extending into the port of chamber wall 61 such that a release rod 63 may couple to spring perch 53. As shown in
Referring to
As shown in
Referring to
Referring to
Indicator housing 75 will secure to launcher body 17 so that indicator rod 77 will extend into an indicator bore 93. A seal 94 will be positioned within indicator housing 75 to seal an outer diameter of indicator housing 75 to indicator bore 93. Indicator bore 93 extends from an exterior surface of launcher body 17 to launcher bore 27. A keyhole 95 may be formed in an interior end of indicator bore 93. Interior end 76 of indicator rod 77 inserts into keyhole 95 so that indicator rod 77 may rotate on an axis 97. Flapper 83 will be spaced along axis 97 from interior end 76 so that interior end 76 may fully seat within keyhole 95. When indicator rod 77 is positioned within indicator bore 93 and seated within keyhole 95, flapper 83 will extend into launcher bore 27. In the illustrated embodiment, flapper 83 will extend from indicator rod 77 such that axis 29 of launcher bore 27 may pass through an outer end of flapper 83. In other embodiments, the outer end of flapper 83 may be proximate to axis 29 of launcher bore 27, but axis 29 may not pass through the outer end of flapper 83.
As shown in
As shown in
During operation of dart launcher 11, dart release assembly 19 will be in the position shown in
When release of dart 33 is desired, pressure will be supplied to port 47 to act on piston head 45. This will result in movement of piston 41 from the position shown in
As dart 33 moves through launcher bore 27, it will contact flapper 83 as shown in
Accordingly, the disclosed embodiments provide numerous advantages. For example, the disclosed embodiments provide a dart launcher capable of launching darts, balls, or plugs of different sizes. In addition, the disclosed embodiments provide a pressure balancing system to prevent premature release of the dart that may be caused by hydraulic pressure within the launcher bore. The disclosed embodiments also allow for maintenance of circulation pressure within the coupled tubing string while dropping the dart. Still further, the disclosed embodiments provide a visual indicator of a successful dart launch, that requires no external energy source, can be seen from a distance, and is easy to assemble.
It is understood that the present invention may take many forms and embodiments. Accordingly, several variations may be made in the foregoing without departing from the spirit or scope of the invention. Having thus described the present invention by reference to certain of its preferred embodiments, it is noted that the embodiments disclosed are illustrative rather than limiting in nature and that a wide range of variations, modifications, changes, and substitutions are contemplated in the foregoing disclosure and, in some instances, some features of the present invention may be employed without a corresponding use of the other features. Many such variations and modifications may be considered obvious and desirable by those skilled in the art based upon a review of the foregoing description of preferred embodiments. Accordingly, it is appropriate that the appended claims be construed broadly and in a manner consistent with the scope of the invention.
Claims
1. A wellbore drop member launcher comprising:
- a launcher body defining a central bore having a central bore axis, the launcher body having a lower end configured to attach to a string of pipe extending into a wellbore;
- the launcher body defining a launcher bore having a launcher bore axis at an angle to the central bore axis, the launcher bore in fluid communication with the central bore;
- a release assembly coupled to the launcher body and having a release rod protruding into the launcher bore to prevent movement of a drop member positioned within the launcher bore in a drop member hold position;
- wherein the release assembly is configured to move the release rod to a drop member release position to selectively release the drop member positioned within the launcher bore; and
- a visual indicator assembly coupled to the launcher body and configured to provide a mechanically produced visual indication that the drop member has moved from the launcher bore to the central bore.
2. The wellbore drop member launcher of claim 1, wherein the release assembly comprises:
- a piston assembly coupled to the release rod and configured to move the release rod between the drop member hold position and the drop member release position; and
- wherein the piston assembly biases the release rod to the drop member hold position.
3. The wellbore drop member launcher of claim 2, further comprising:
- a release body housing interposed between the piston assembly and the launcher body, the release rod at least partially disposed within the release body housing when in the drop member hold position and a portion of the piston assembly coupling to the release rod within the release body housing;
- a window having a length formed in a portion of a release body housing;
- an indicator screw threaded into the portion of the piston assembly so that an end of the screw is visible through the window; and
- wherein the indicator screw moves from a first end of the window to a second end of the window when the piston assembly operates to move the release rod between the drop member hold and the drop member release positions, providing a visual indication of release assembly actuation.
4. The wellbore drop member launcher of claim 3, wherein:
- the release rod defines a pressure passage extending from an end of the release rod disposed within the launcher bore through a center of the release rod to an annular chamber within the release body housing; and
- wherein the pressure passage is configured to equalize pressure between the release body housing and the launcher bore to prevent premature dart member release.
5. The wellbore drop member launcher of claim 2, wherein the piston assembly is a hydraulically actuated piston assembly.
6. The wellbore drop member launcher of claim 2, wherein the piston assembly is a pneumatically actuated piston assembly.
7. The wellbore drop member launcher of claim 1, wherein the visual indicator assembly comprises:
- an indicator bore defined by the launcher body extending from an exterior of the launcher body to the launcher bore;
- an indicator housing coupled to the launcher body proximate to the indicator bore;
- an indicator rod extending through the indicator housing into the indicator bore;
- a flapper on an end portion of the indicator rod;
- wherein the flapper is perpendicular to the indicator rod and extends from the indicator bore into the launcher bore;
- an arm secured to an end of the indicator rod that protrudes from the indicator housing and located so as to be visible to an operator;
- wherein the arm extends from the indicator rod perpendicular to the indicator rod and parallel to the flapper; and
- wherein as the drop member passes the flapper it rotates the flapper, indicator rod, and arm to indicate release of the drop member.
8. The wellbore drop member launcher of claim 7, further comprising:
- a pre-release detent formed in a surface of the indicator rod;
- a post-release detent formed in a surface of the indicator rod axially aligned with the pre-release detent and circumferentially spaced from the pre-release detent; and
- a spring plunger disposed within the indicator housing and adapted to insert into the pre-release detent to limit rotation of the indicator rod prior to passage of the drop member; and
- the spring plunger further adapted to release from the pre-release detent to allow rotation of the indicator, rod as the drop member passes and insert into the post-release detent to prevent further rotation of the indicator rod following passage of the drop member.
9. The wellbore drop member launcher of claim 7, wherein the flapper, indicator rod, and arm rotate ninety degrees.
10. A wellbore drop member launcher comprising:
- a launcher body defining a central bore having a central bore axis, the launcher body having a lower end configured to attach to a tubing string extending into a wellbore;
- the launcher body defining a launcher bore having a launcher bore axis at an angle to the central bore axis, the launcher bore in fluid communication with the central bore;
- a release assembly coupled to the launcher body and having a release rod protruding into the launcher bore to prevent movement of a drop member positioned within the launcher bore into the tubing string;
- wherein the release assembly is configured to move the release rod with a piston assembly from a drop member hold position to a drop member release position to selectively release the drop member;
- wherein the piston assembly biases the release rod to the drop member hold position;
- a pressure passage defined by the release rod and configured to equalize pressure between a compressible portion of the piston assembly and the launcher body to prevent premature drop member release, the pressure passage extending from an end of the release rod disposed within the launcher bore through a center of the release rod to an annular chamber within the piston assembly;
- an indicator housing coupled to the launcher body proximate to an indicator bore defined by the launcher body and extending from an exterior of the launcher body to the launcher bore;
- an indicator rod extending through the indicator housing into the indicator bore, the indicator rod having a flapper on an end portion of the indicator rod and an arm secured to an opposite end of the indicator rod;
- wherein the flapper and the arm are perpendicular to the indicator rod and parallel to each other;
- wherein the flapper extends from the indicator bore into the launcher bore and the arm is located so as to be visible to an operator;
- wherein as the drop member passes the flapper it will rotate the flapper, indicator rod, and arm to indicate release of the drop member.
11. The wellbore drop member launcher of claim 10, further comprising:
- a release body housing coupling the piston assembly to the launcher bore, the release rod partially disposed within the release body housing;
- a window having a length formed in a portion of a release body housing;
- an indicator screw threaded into a portion of the piston assembly so that an end of the screw is visible through the window; and
- wherein the indicator screw moves from a first end of the window to a second end of the window when the piston assembly operates to move the release rod, providing a visual indication of release assembly actuation.
12. The wellbore drop member launcher of claim 10, wherein the piston assembly is a hydraulically actuated piston assembly.
13. The wellbore drop member launcher of claim 10, wherein the piston assembly is a pneumatically actuated piston assembly.
14. The wellbore drop member launcher of claim 10, further comprising:
- a pre-release detent formed in a surface of the indicator rod;
- a post-release detent formed in a surface of the indicator rod axially aligned with the pre-release detent and circumferentially spaced from the pre-release detent; and
- a spring plunger disposed within the indicator housing and adapted to insert into the pre-release detent to limit rotation of the indicator rod prior to passage of the drop member; and
- the spring plunger further adapted to release from the pre-release detent to allow rotation of the indicator rod as the drop member passes and insert into the post release detent to prevent further rotation of the indicator rod following passage of the drop member.
15. The wellbore drop member launcher of claim 10, wherein the flapper, indicator rod, and arm rotate ninety degrees.
16. A method for launching a drop member into a wellbore tubing string, comprising:
- (a) providing a launcher body having a central bore with a central bore axis and a launcher bore with a launcher bore axis at an angle to the central bore axis and in fluid communication with the central bore;
- (b) placing a drop member in the launcher bore and resting the drop member on a release rod of a release assembly coupled to the launcher body;
- (c) coupling a visual indicator assembly to the launcher body so that the visual indicator assembly is in communication with the launcher bore at a location downstream from the release assembly;
- (d) coupling the launcher body in line with the tubing string so that the central bore of the launcher body aligns with a body passage through the tubing string;
- (e) actuating the release assembly to allow the drop member to move from the launcher body into the central bore where the drop member may move down the tubing string; and
- (f) actuating the visual indicator assembly with the drop member as the drop member moves from the launcher bore into the central bore.
17. The method of claim 16, wherein step (e) comprises applying hydraulic pressure to a piston assembly of the release assembly to move the release rod from the launcher bore.
18. The method of claim 16, wherein step (e) comprises applying pneumatic pressure to a piston assembly of the release assembly to move the release rod from the launcher bore.
19. The method of claim 16, wherein step (f) comprises:
- moving a flapper of the visual indicator assembly with the drop member to rotate an indicator rod and an arm coupled to the indicator rod; and
- signaling to an operator that the drop member has moved into the central bore with rotation of the arm.
20. The method of claim 19, wherein further comprising:
- securing a spring plunger within a housing of the visual indicator assembly adapted to insert into a pair of circumferentially spaced detents; and
- limiting rotation of the indicator rod by inserting a plunger of the spring plunger into the detents.
Type: Application
Filed: Dec 27, 2011
Publication Date: Jun 27, 2013
Applicant: VETCO GRAY INC. (Houston, TX)
Inventors: Chad Eric Yates (Houston, TX), Shripad Hedge (Bangalore), Dinesh Narayan (Bangalore)
Application Number: 13/337,985
International Classification: E21B 33/13 (20060101);