WO2007124418A2

WO2007124418A2 - Two-door elevator

Info

Publication number: WO2007124418A2
Application number: PCT/US2007/067080
Authority: WO
Inventors: Brian Ellis; Stanislaw Casimir Sulima; Craig Weems; Faisal Yousef
Original assignee: Nabors Global Holdings Ltd.
Priority date: 2006-04-21
Filing date: 2007-04-20
Publication date: 2007-11-01
Also published as: WO2007124418A3; US20080093870A1

Abstract

An elevator assembly (100) for moving a tubular member (200), the elevator assembly comprising first and second doors (120a, 120b) each connected to a front side of a body (110) such that the first and second doors rotate between open and closed positions, wherein the body and the doors collectively encircle the tubular member when the doors are in the closed position and wherein a center of mass of the elevator assembly remains substantially unchanged regardless of whether the first and second doors are in the open or closed position.

Description

TWO-DOOR ELEVATOR

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of U.S. Provisional Application No. 60/793,782, entitled "TWO-DOOR ELEVATOR," filed April 21, 2006, the disclosure of which is hereby incorporated herein by reference.

[0002] This application is also related to commonly-assigned US Utility Application No. , entitled "TWO-DOOR ELEVATOR," filed concurrently herewith, the disclosure of which is hereby incorporated herein by reference.

[0003] This application is also related to commonly-assigned GCC Application No. , entitled "TWO-DOOR ELEVATOR," filed concurrently herewith, the disclosure of which is hereby incorporated herein by reference.

BACKGROUND

[0004] Elevators are hinged mechanisms that close around drillpipe or other drill string components to facilitate lowering into or lifting out of a wellbore. One type of elevator, sometimes called a "single hinge split elevator," has two halves or arms which swing away from the pipe when in an open position. In a closed position, the elevator arms latch together, forming a Io ad- bearing ring around the pipe.

[0005] Another type of elevator, sometimes called a "side door elevator," has a single door that swings open and closed. The "side door" elevator tends to become imbalanced when the door is open. That is, the weight of the door causes the elevator to rotate or tilt toward the door. This can make the elevator difficult to control. Additionally, engaging the pipe with the elevator is difficult without direct worker intervention. Typically, a worker manually straightens the elevator for engagement and locking.

[0006] The "single hinge split" type elevator also tends to tilt. Additionally, the natural state of this type of elevator is closed, which makes it difficult to engage the pipe as workers or hydraulics fight against the pull of gravity on the arms. Moreover, heavy ears on the elevator often exacerbate the difficulties associated with the "single hinge split" type elevator. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] The present disclosure is best understood from the following detailed description when read with the accompanying figures. It is emphasized that, in accordance with the standard practice in the industry, various features may not be drawn to scale. In fact, the dimensions of the various features may be arbitrarily increased or reduced for clarity of discussion.

[0008] Fig. 1 is a perspective view of apparatus depicted in a first mode of operation according to one or more aspects of the present disclosure.

[0009] Fig. 2 is partial perspective view of the apparatus shown in Fig. 1 depicted in the operational mode shown in Fig. 1.

[0010] Fig. 3 is a perspective view of the apparatus shown in Figs. 1 and depicted in another mode of operation.

[0011] Fig. 4 is a partial perspective view of the apparatus shown Figs. 1-3 depicted in the operational mode shown in Fig. 3.

[0012] Fig. 5 is a perspective view of the apparatus shown in Figs. 1-4 depicted in yet another mode of operation.

[0013] Fig. 6 is a perspective view of the apparatus shown in Figs. 1-5 depicted in the operational mode shown in Fig. 5.

[0014] Fig. 7 is a perspective view of the apparatus shown in Figs. 1-6 depicted in the operational mode shown in Fig. 5.

[0015] Fig. 8 is a perspective view of the apparatus shown in Figs. 1-7 depicted in the operational mode shown in Figs. 1 and 2.

[0016] Fig. 9 is a flow-chart diagram of a method according to one or more aspects of the present disclosure. DETAILED DESCRIPTION

[0017] It is to be understood that the following disclosure provides many different embodiments, or examples, for implementing different features of various embodiments. Specific examples of components and arrangements are described below to simplify the present disclosure. These are, of course, merely examples and are not intended to be limiting. In addition, the present disclosure may repeat reference numerals and/or letters in the various examples. This repetition is for the purpose of simplicity and clarity and does not in itself dictate a relationship between the various embodiments and/or configurations discussed. Moreover, the formation of a first feature over or on a second feature in the description that follows may include embodiments in which the first and second features are formed in direct contact, and may also include embodiments in which additional features may be formed interposing the first and second features, such that the first and second features may not be in direct contact.

[0018] The present disclosure relates generally to an elevator for lifting and lowering tubulars or other downhole components, such as pipe or drill string components. More specifically, the present disclosure is directed towards an elevator assembly comprising two doors. The doors may be constructed and connected to the elevator assembly such that the center of mass of the elevator assembly remains in substantially the same location, regardless of whether the doors are open or closed. The elevator assembly may further comprise one or more spring- locking assemblies and/or one or more load-locking assemblies. Additionally, cylinders used to open and close the doors may hold the doors in position.

[0019] Referring to Figs. 1-3 collectively, illustrated are perspective and partial views of an elevator assembly 100 according to one or more aspects of the present disclosure. The elevator assembly 100 includes a body 110, a first door 120a rotatably coupled to the body 110 by a first hinge pin 125a, and a second door 120b rotatably coupled to the body 110 by a second hinge pin 125b. The first door 120a includes a clevis, flange or other attachment means (hereafter referred to as a clevis) 130a protruding therefrom, and the second door 120b includes a similar clevis 130b protruding therefrom. One end of a compression cylinder or other type of actuator (such actuator types hereafter collectively referred to as an actuator) 135a is pinned or otherwise rotatably coupled to the clevis 130a of the first door 120a, whereas the other end of the actuator 135a is pinned or otherwise rotatably coupled to a first flange 140a extending from the body 110. One end of another actuator 135b is pinned or otherwise rotatably coupled to the clevis 130b of the second door 120b, whereas the other end of the actuator 135b is pinned or otherwise rotatably coupled to a second flange 140b extending from the body 110. The elevator assembly 100 also includes ears 145a, 145b extending in opposing directions from the body 110, as well as one or more inserts 150 directly or indirectly coupled to and/or recessed within the inner diameter 112 of the body 110, the first door 120a and/or the second door 120b.

[0020] The load-locking assembly may include a load-locking cavity or recess 124a in the first door 120a, and a corresponding load-locking projection 124b in the second door 120b. Additionally, the second door 120b may have a bottom portion 122b and atop portion 121b. The top portion 121b may include a spring or other device that would tend to separate the top portion 121b and the bottom portion 122b, and possibly cause some of the top portion 121b to project above the rest of the elevator assembly 100. Upon loading the elevator assembly 100 by engaging a tubular member (not shown), the weight of the collar or other portion of the tubular member would first engage the top portion 121b of the second door 120b. The weight would then overcome the resistance of the spring in the top portion 121b, and the top portion 121b would move downwardly, such that the load-locking projection 124b in the second door 120b engages the load-locking recess 124a in the first door 120a.

[0021] For example, in the exemplary embodiment shown in Figs. 1-3, the second door 120b includes an upper portion 121b and a lower portion 122b which are kept in rotational alignment relative to the hinge pin 125b by alignment guides 123b, which are best shown in Fig. 3. The upper portion 121b is free to translate a short distance axially relative to the lower portion 122b (in an up-and-down direction relative to the page in the orientations shown in Figs. 1-3). However, the upper portion 121b is spring-biased upwards, away from the lower portion 122b. Consequently, when the elevator 100 is not engaged with a tubular member, there is a slight gap between the upper portion 121b and the lower portion 122b, as best shown in Fig. 3. However, during the operational mode shown in Figs. 1 and 2, the weight of a tubular member (not shown) engaged by the elevator 100 urges the upper portion 121b down towards the lower portion 122b. Consequently, a projection 124b extending from the second door 120b translates into an aperture 124a of the first door, thereby locking the first and second doors 120a, 120b together and preventing them from inadvertently opening.

[0022] At least a portion of each of the ears 145a, 145b may be integral to the body. However, as best shown in Fig. 3, a portion of each of the ears 145a, 145b may include one or more discrete members 147a, 147b coupled to the integral portion of the ears 145a, 145b, such as by mechanical fasteners 148a, 148b, among other possible coupling means. The ears 145a, 145b, including any discrete components 147a, 147b, 148a, 148b thereof, may be mirror-images of each other, or otherwise be symmetrical relative to the centerline of the elevator 100. The ears 145a, 145b may additionally be located in a plane substantially coinciding with the center of mass of the elevator.

[0023] The spring- Io eking assemblies 155a, 155b may have a moveable locking pin 156 which is held in a position that is outside of a spring- Io eking cavity 158 when the door is open. When the door is closed, a locking spring 157 pushes the moveable locking pin 156 into the spring-locking cavity 158, causing the door to be locked in the closed position. In order to open the door, hydraulic or pneumatic pressure may be used to compress the locking spring 157.

[0024] For example, in the exemplary embodiment shown in Figs. 1-3, the first and second doors 120a, 120b are locked in a closed position via the spring-locking assemblies 155a, 155b, respectively. The locking assemblies 155a, 155b each include a retractable member 156 and a spring 157 which biases the retractable member 156 towards the position shown in Fig. 2 in which the member 156 is received within an aperture 158 of the corresponding first or second door 120a, 120b. The spring 157 may be or comprise one or more compression springs, Bellville springs, and/or other biasing means. As shown in Fig. 4, the member 156 is configured to be retracted out of the aperture 158 to unlock the corresponding first or second door 120a, 120b and allow rotation of the door around the corresponding hinge pin 125a, 125b.

[0025] Such retraction may be via pneumatic or hydraulic pressure or vacuum supplied to an inner chamber 159 of the assemblies 155a, 155b. For example, each assembly 155a, 155b may include a pneumatic or hydraulic fitting 160 for fluidicly coupling the inner chamber 159 with a hose or other connection means extending to a pneumatic or hydraulic pressure or vacuum source. In the exemplary embodiment shown in Figs. 2 and 4, the inner chamber 159 is configured to receive pneumatic or hydraulic fluid, which acts to urge the member 156 against the spring 157, thereby retracting the member 156 from the aperture 158 of the door 120a. However, other means for retracting the member 156 from the aperture 158 are also within the scope of the present disclosure. [0026] Referring to Fig. 5, with continued reference to Figs. 1-4, illustrated is a perspective view of another mode of operation of the elevator 100 in which the actuators 135a, 135b have contracted in length and, thereby, opened the first and second doors 120a, 120b. The actuators 135a, 135b may each be or comprise a pneumatic or hydraulic cylinder having a cylinder barrel end coupled to the corresponding flange 140a, 140b, and another end from which extends a piston rod coupled to the corresponding clevis 130a, 130b. The actuators 135a, 135b may be coupled to the corresponding flange 140a, 140b and clevis 130a, 130b by pins, threaded fasteners, and/or other mechanical fastening means 165 configured to allow rotation. For example, like the clevises 130a, 130b, the flanges 140a, 140b may include a clevis or other flared portion configured to receive a flange extending from the cylinder barrel end of the actuators 135a, 135b and a clevis pin extending therethrough.

[0027] The doors 120a, 120b, actuators 135a, 135b, and/or locking assemblies 155a, 155b may be constructed and positioned within the elevator assembly 100 such that the center of mass of the elevator assembly 100 remains in substantially the same location regardless of whether the doors 120a, 120b are in the open position shown in Fig. 5 or the closed position shown in Figs. 1-4. For example, as the doors 120a, 120b move towards the open position shown in Fig. 5, they would tend to transition the center of mass of the elevator 100 away from the center of mass of the elevator 100 when the doors are closed, where such transition is generally in a direction similar to the direction in which the doors open. However, at the same time the doors 120a, 120b are opening, the locking pin 156 of the locking assemblies 155a, 155b and/or the piston rod of the actuators 135a, 135b are moving in a direction opposite to the direction in which the doors are opening. It is this transition of the mass of the locking pins 156 and/or piston rods, for example, that counterbalances the movement of the mass resulting from opening the doors. Consequently, the elevator 100 can remain neutrally balanced whether the doors are in or moving towards the open or closed position, or the center of mass of the elevator 100 can otherwise remain substantially unchanged as the doors move between the open and closed positions. This may, accordingly, reduce or eliminate the need for a worker to straighten or tilt the elevator assembly 100 after it has engaged a tubular member.

[0028] Referring to Figs. 6-8, collectively, illustrated are perspective views of the elevator 100 shown in Figs. 1-5 in the operational mode depicted in Fig. 5 where the elevator 100 is also being engaged with a tubular member 200. The tubular member 200 is a conventional or future-developed tubular member used in, for example, the oil services industry. For example, the tubular member 200 includes a collar 210 having a greater outer diameter relative to the substantial length of the tubular member 200.

[0029] In the operational mode shown in Fig. 6, the first and second doors 120a, 120b are opened by operating the actuators 135a, 135b, respectively. The elevator assembly 100 is then oriented relative to the tubular member 200 such that the flanges 140a, 140b extending from the body 110 contact the outer surface of the tubular member 200. The flanges 140a, 140b may be tapered at, for example, about 45° (e.g., see Fig. 3). Accordingly, the flanges 140a, 140b may function to tilt the elevator assembly 100 into axial alignment with the tubular member 200 as a result of the contact between the flanges 140a, 140b and the outer surface of the tubular member 200, as shown in Fig. 7. Thereafter, as shown in Fig. 8, the doors 120a, 120 may be closed around the tubular member 200 by operating the actuators 135a, 135b, respectively. As the doors 120a, 120b reach the fully closed position, the spring- locking assemblies 155a, 155b force the locking pins 156 into the locking apertures 158 (e.g., see Figs. 2 and 4). Subsequently, the elevator assembly 100 may be lifted vertically relative to the tubular member 200, and ultimately the weight of the tubular member 200 will bias the upper portion 121b of the second door 120b downward to engage the locking pin 124 of the second door 120b with the locking aperture 124a of the first door 120a (i.e., engaging the load-locking assembly). Thus, the doors 120a, 120b become double-locked, further ensuring that the tubular member 200 does not inadvertently escape the elevator assembly 100.

[0030] Additionally, during the operation described above with respect to Figs. 1-8, the doors 120a, 120b may be configured to aid in centralizing the elevator assembly 100 relative to the tubular member 200 when initially orienting the elevator assembly 100 relative to the tubular member 200. Moreover, it should be noted that the doors 120a, 120b may open and close concurrently or independently in any sequence, whether such operation is manual or automatic, and whether such operation is controlled remotely or locally.

[0031] As described above, the elevator assembly 100 may also include dyes or inserts 150. The inserts 150 coupled to or otherwise associated with the second door 120b may be fixed to the top portion 121b and allowed to float with respect to the bottom portion 122b. The remaining inserts 150 may all float relative to the body 110 and/or the first door 120a. In this manner, when a load is introduced, the insert 150 associated with the second door 120b may be configured to move, thereby causing the top portion 121b to move downwardly, such that the load-locking projection 124b in the second door 120b engages the load-locking recess 124a in the first door 120a. In addition to providing an alternative to using a collared tubular, the inserts 150 may also be configured to allow the elevator assembly 100 to engage or otherwise be utilized with multiple ranges of tubular sizes, such as in embodiments in which the inserts 150 are replaceable components effectively decreasing or increasing the inner engaging profile of the elevator assembly 100.

[0032] The elevator assembly 100 may also include a failsafe indicator that provides the operator with an indication that the doors 120a, 120b have locked. This indicator may be particularly useful for automatic closing of the doors, whether hydraulic or pneumatic.

[0033] Referring to Fig. 9, illustrated is a flow-chart diagram of a method 900 for moving a tubular member according to one or more aspects of the present disclosure. The method 900 is an exemplary embodiment of the implementation of one or more of the operational modes described above with respect to Figs. 1-8, and may utilize the elevator assembly 100 shown in Figs. 1-8.

[0034] The method 900 includes a step 910 comprising orienting an elevator assembly around the tubular member such that the axis of the elevator assembly is substantially aligned with the axis of the tubular member. The method 900 also includes a step 920 comprising closing the elevator assembly around the tubular, wherein the elevator assembly comprises first and second doors each connected to a front side of a body such that the first and second doors rotate between open and closed positions, wherein the body and the doors collectively encircle the tubular member when the doors are in the closed position, and wherein a center of mass of the elevator assembly remains substantially unchanged regardless of whether the first and second doors are in the open or closed position. The method 900 also includes a step 930 comprising locking the elevator assembly doors in the closed position.

[0035] The closing step 920 may comprise pneumatically or hydraulically operating first and second actuators operable to open and close the first and second doors. The locking step 930 may comprise inserting first and second locking pins into corresponding first and second cavities, respectively, in the first and second doors, respectively. The locking step 930 may alternatively or additionally comprise applying an axial load to atop part of the second door thereby translating the top part of the second door towards a bottom part of the second door resulting in the insertion of a locking projection extending from the top part of the second door into a corresponding cavity in the first door. [0036] In view of all of the above and Figs. 1-8, it should be clear to those skilled in the art that the present disclosure introduces an elevator assembly for moving a tubular member, the elevator assembly comprising first and second doors each connected to a front side of a body such that the first and second doors rotate between open and closed positions, wherein the body and the doors collectively encircle the tubular member when the doors are in the closed position, and wherein a center of mass of the elevator assembly remains substantially unchanged regardless of whether the first and second doors are in the open or closed position. The elevator assembly may further comprise first and second spring-locking assemblies configured to lock the first and second doors, respectively, in the closed position. The first and second spring-locking assemblies may each include a locking pin biased towards the corresponding first or second door and configured to be received within a locking aperture of the first or second door when the first or second door is in the closed position. The elevator assembly may further comprise a load-locking assembly configured to lock the doors in the closed position upon application of an axial load to the elevator assembly. The load-locking assembly may comprise a load-locking cavity located in the first door and a load-locking projection extending from the second door, wherein the application of the axial load results from the weight of the tubular member and causes the load-locking projection to enter the load-locking cavity. The elevator assembly may further comprise first and second actuators operable to open and close the first and second doors, respectively. The actuators may be hydraulic actuators or pneumatic actuators.

[0037] The present disclosure also introduces a method for moving a tubular member, comprising orienting an elevator assembly around the tubular member such that the axis of the elevator assembly is substantially aligned with the axis of the tubular member, closing the elevator assembly around the tubular, wherein the elevator assembly comprises first and second doors each connected to a front side of a body such that the first and second doors rotate between open and closed positions, wherein the body and the doors collectively encircle the tubular member when the doors are in the closed position, and wherein a center of mass of the elevator assembly remains substantially unchanged regardless of whether the first and second doors are in the open or closed position, and locking the elevator assembly doors in the closed position. Closing the elevator assembly may comprise pneumatically or hydraulically operating first and second actuators operable to open and close the first and second doors. Locking the elevator assembly doors in the closed position may comprise inserting first and second locking pins into corresponding first and second cavities, respectively, in the first and second doors, respectively. Locking the elevator assembly doors in the closed position may alternatively or additionally comprise applying an axial load to a top part of the second door thereby translating the top part of the second door towards a bottom part of the second door resulting in the insertion of a locking projection extending from the top part of the second door into a corresponding cavity in the first door.

[0038] The present disclosure also introduces an elevator assembly for moving a tubular member, comprising first and second doors each connected to a front side of a body such that the first and second doors rotate between open and closed positions, wherein the body and the doors collectively encircle the tubular member when the doors are in the closed position, and first and second spring-locking assemblies configured to lock the first and second doors, respectively, in the closed position. The first and second spring- locking assemblies may each include a locking pin biased towards the corresponding first or second door and configured to be received within a locking aperture of the first or second door when the first or second door is in the closed position. The elevator assembly may further comprise a load-locking assembly configured to lock the doors in the closed position upon application of an axial load to the elevator assembly. The load-locking assembly may comprise a load-locking cavity located in the first door and a load-locking projection extending from the second door, wherein the application of the axial load results from the weight of the tubular member and causes the load-locking projection to enter the load-locking cavity. The elevator assembly may further comprise first and second actuators operable to open and close the first and second doors, respectively. The actuators may be hydraulic or pneumatic actuators.

[0039] The foregoing outlines features of several embodiments so that those skilled in the art may better understand the aspects of the present disclosure. Those skilled in the art should appreciate that they may readily use the present disclosure as a basis for designing or modifying other processes and structures for carrying out the same purposes and/or achieving the same advantages of the embodiments introduced herein. Those skilled in the art should also realize that such equivalent constructions do not depart from the spirit and scope of the present disclosure, and that they may make various changes, substitutions and alterations herein without departing from the spirit and scope of the present disclosure.

Claims

WHAT IS CLAIMED IS:

1. An elevator assembly for moving a tubular member, comprising: first and second doors each connected to a front side of a body such that the first and second doors rotate between open and closed positions, wherein the body and the doors collectively encircle the tubular member when the doors are in the closed position, and wherein a center of mass of the elevator assembly remains substantially unchanged regardless of whether the first and second doors are in the open or closed position.

2. The elevator assembly of claim 1 further comprising first and second spring- locking assemblies configured to lock the first and second doors, respectively, in the closed position.

3. The elevator assembly of claim 2 wherein the first and second spring-locking assemblies each include a locking pin biased towards the corresponding first or second door and configured to be received within a locking aperture of the first or second door when the first or second door is in the closed position.

4. The elevator assembly of claim 1 further comprising a load-locking assembly configured to lock the doors in the closed position upon application of an axial load to the elevator assembly.

5. The elevator assembly of claim 4 wherein the load-locking assembly comprises a load-locking cavity located in the first door and a load-locking projection extending from the second door, and wherein the application of the axial load results from the weight of the tubular member and causes the load-locking projection to enter the load-locking cavity.

6. The elevator assembly of claim 1 further comprising first and second actuators operable to open and close the first and second doors, respectively.

7. The elevator assembly of claim 6 wherein the actuators are hydraulic actuators.

8. The elevator assembly of claim 6 wherein the actuators are pneumatic actuators.

9. A method for moving a tubular member, comprising: orienting an elevator assembly around the tubular member such that the axis of the elevator assembly is substantially aligned with the axis of the tubular member; closing the elevator assembly around the tubular, wherein the elevator assembly comprises first and second doors each connected to a front side of a body such that the first and second doors rotate between open and closed positions, wherein the body and the doors collectively encircle the tubular member when the doors are in the closed position, and wherein a center of mass of the elevator assembly remains substantially unchanged regardless of whether the first and second doors are in the open or closed position; and locking the elevator assembly doors in the closed position.

10. The method of claim 9 wherein closing the elevator assembly comprises pneumatically operating first and second actuators operable to open and close the first and second doors.

11. The method of claim 9 wherein closing the elevator assembly comprises hydraulically operating first and second actuators operable to open and close the first and second doors.

12. The method of claim 9 wherein locking the elevator assembly doors in the closed position comprises inserting first and second locking pins into corresponding first and second cavities, respectively, in the first and second doors, respectively.

13. The method of claim 9 wherein locking the elevator assembly doors in the closed position comprises applying an axial load to a top part of the second door thereby translating the top part of the second door towards a bottom part of the second door resulting in the insertion of a locking projection extending from the top part of the second door into a corresponding cavity in the first door.

14. An elevator assembly for moving a tubular member, comprising: first and second doors each connected to a front side of a body such that the first and second doors rotate between open and closed positions, wherein the body and the doors collectively encircle the tubular member when the doors are in the closed position; and first and second spring-locking assemblies configured to lock the first and second doors, respectively, in the closed position.

15. The elevator assembly of claim 14 wherein the first and second spring-locking assemblies each include a locking pin biased towards the corresponding first or second door and configured to be received within a locking aperture of the first or second door when the first or second door is in the closed position.

16. The elevator assembly of claim 14 further comprising a load-locking assembly configured to lock the doors in the closed position upon application of an axial load to the elevator assembly.

17. The elevator assembly of claim 16 wherein the load-locking assembly comprises a load-locking cavity located in the first door and a load-locking projection extending from the second door, and wherein the application of the axial load results from the weight of the tubular member and causes the load-locking projection to enter the load-locking cavity.

18. The elevator assembly of claim 14 further comprising first and second actuators operable to open and close the first and second doors, respectively.

19. The elevator assembly of claim 18 wherein the actuators are hydraulic actuators.

20. The elevator assembly of claim 18 wherein the actuators are pneumatic actuators.