Elevator With Dual Lifting Ears

Abstract

A pipe elevator having at least two pairs of opposing hanger ears is provided. One pair of hanger ears is sized to support the maximum load capacity of the elevator and these hanger ears are configured to match with draw-works lifting links having the maximum elevator load capacity. At least one pair of hanger ears is sized to support a desired subsequent elevator loading and these hanger ears are configured to match with a subsequent draw-works lifting links sufficient to support the desired subsequent elevator loading. A pipe support assembly is further provided for holding the pipe within the elevator.

Description

PRIORITY

This application claims priority to U.S. provisional application Ser. No. 62/043,938 filed Aug. 29, 2014 entitled “Elevator With Dual Lifting Ears”, the entire content of which is incorporated by reference.

FIELD OF INVENTION

This invention relates to oil well pipe handling devices typically referred to as elevators. More particularly, the present invention relates to an elevator having dual lift ears that will allow the elevator to be matched and used with lifting links of differing sizes and load capacities during the drilling of an oil and gas well.

BACKGROUND

The drilling of an oil and gas well requires multiple segments or joints of pipe to threadedly joined or strung together to form a pipe string. Such pipe segments may comprise a drill string used to support a drill bit to advance the wellbore or a casing string that lines the advancing wellbore. A pipe gripping rotary spider that fits into the opening of the rotary table of a drilling rig and a pipe lifting elevator are typically used in conjunction to join the pipe segments together to form the pipe string. The spider and the elevator are used to alternately hold and release the downhole pipe string and each additional pipe segment added to the pipe string. The spider is used to grip the wellbore pipe string as each additional pipe segment is added. The elevator is used to move and suspend each additional pipe segment above the spider in axial alignment with the wellbore pipe string gripped by the spider where the additional pipe segment can be threadedly attached to the wellbore pipe string. Elevators typically have lifting pins or ears that can be pivotally mounted on lifting links suspended from a hoist, or travelling block, on a hoist line, attached to the draw-works of a rig derrick.

Elevator are designed to accommodate a specified maximum working load and their lifting ears are designed and dimensioned to accommodate that maximum working load and to correspond with lifting links also designed to support that maximum working load. The working load is derived from the anticipated pipe string load, which is a function of wellbore depth and the weight of the pipe or casing being used.

Elevators are selected based upon their maximum working load capacity. An elevator designed for a maximum working load of 750 tons will have lifting ears sized to match with lifting links suitable for lifting 750 tons. Lifting links suitable for elevators designed for a maximum working load less than 750 tons, such an elevator having a maximum working load of 500 tons, will typically be too small and will not fit the lifting ears of an elevator designed for a maximum working load of 750 tons. Lifting links suitable for use with an elevator designed for a maximum working load of 750 tons will typically be too large and will not fit the lifting ears of an elevator designed for a maximum working load of 500 tons.

The potential lack of compatibility between the lifting links of the hoist or travelling block and the lifting ears of a selected elevator will often require drilling operators and contractors to have multiple elevators and multiple sets of lifting links on hand in order to accommodate the anticipated pipe string loads as the size of the pipe segments change during drilling operations. The rental or purchase of multiple elevators and sets of lifting links increases the cost of drilling operations. Further, the additional time required to exchange elevators and lifting links during drilling increases the time required to complete drilling operations thus increasing the cost of the well. The additional work required in changing the elevator and links also increases the risk of injury to workers performing these tasks.

It would be an advantage to have an elevator that does not have to be changed as size of pipe segments change during drilling operations. It would also be an advantage to have an elevator with lifting ears that will correspond to and be matched with lifting links of a variety of load capacities. It will also be an advantage to eliminate the need and expense of having elevators of different working load capacities and multiple sets of lifting ears on hand during drilling sized to accommodate changes in pipe sizes. It would also be an advantage to eliminate the risk posed to workers when changing elevators and links. An elevator with more than one set of lifting ears provide these advantages and give the drilling operator or contractor additional options when selecting equipment for use at a drilling location. An elevator with more than one set of lifting ears will lead to savings in equipment costs and in rig setup time ultimately reducing the cost of drilling.

SUMMARY

An elevator having dual lifting pins or lifting ears is disclosed. The elevator is comprised of an elevator body having a first pair of hanger ears sized to support a desired first anticipated working load and second pair of hanger ears sized to support a desired second anticipated working load. The first and second pairs of hanger ears are shaped to mate with a lifting links sized and configured for a corresponding specified working load and a corresponding hanger ear shape. Each hanger ear of the first and second pairs of hanger ears is fitted with an ear guard to prevent accidental mismatching of lifting links with hanger ears of improper size or unsuitable load capacity.

In one embodiment the elevator will have a ring-shaped body providing a central opening for receiving a tubular pipe segment. The ring-shaped body may be a ring inwardly tapered to support a plurality of tapered slips or it may be comprised of a plurality of inwardly tapered vertical plates arranged around a central open with each tapered vertical plate supporting a tapered slip. The slips slide vertically downward and upward on the inwardly tapered surfaces of the body or vertical plates and this upward and downward movement causes the slips to move radially inward and outward with respect to the central opening of the elevator body to grip and release a tubular pipe segment. Pipe gripping dies may be provided on each of the slips in order to enhance the grip of the slips on the pipe segment when the pipe segment is held and supported by the elevator.

The slips are attached by a linkage to a timing ring also having a central opening that is positioned above the elevator body. The timing ring and linkage allow the slips to be moved vertically downward and upward in unison with respect to the elevator body. Hydraulic cylinders having extendable and retractable piston rods attached to the timing ring are mounted on the body. Extension and retraction of the piston rods will move the timing ring and the attached slips upward and downward and radially inward an outward as the slips move along the elevator body. Preferably the hydraulic cylinders are double acting cylinders having attached fluid lines that are remotely operated by moving fluid into and out of the cylinders through the attached fluid lines to extend and retract the cylinder piston rods.

To use the elevator a desired pair of hanger ears is selected from the first and second pairs of hanger ears and the selected pair of hanger ears is mated with selected lifting links suspended from a hoist line and associated draw-works of a drilling rig. The selected lifting links are configured to correspond with the selected pair of hanger ears. The ear guards provided around the hanger ears, and the shape of the hanger ears, prevent the selected pair of hanger ears from being mounted on lifting links that are too small or too large. This will guard against matching the selected pair of lifting ears with lifting links that do not correspond with the working load capacity of the elevator and lifting ears.

The piston rods of the hydraulic cylinders are then extended to lift the timing ring to move the slips upward and horizontally outward away from the central opening of the elevator body providing sufficient clearance to allow a pipe segment to be inserted into the central opening. After the pipe segment enters the central opening of the elevator body, the piston rods of the hydraulic cylinders are retracted to lower the timing ring to move the slips downward and radially inward into the central opening of the elevator body to engage the pipe segment. The hoist and draw-works are then used to lift the lifting links and the pivotally attached elevator with the pipe segment supported by the slips. The weight of the pipe segment on the slips further forces the slips downward and inward along the inwardly tapered surfaces of the body or vertical plates to enhance the hold on the pipe segment. With the pipe segment supported by the slips of the elevator and the elevator supported on the lifting links, the elevator may be moved to position the pipe segment relative to the wellbore pipe string being held in place by a rotary spider. The pipe segment may then be joined to the wellbore pipe string by threadedly attaching the pipe segment to the wellbore pipe string. After the pipe segment is attached to the wellbore pipe string, the spider is manipulated to release the wellbore pipe string leaving the pipe segment and the newly attached wellbore pipe string supported by the elevator.

DRAWINGS

FIG. 1 is a top view of the dual ear elevator of the present invention.

FIG. 2 is an elevation cross-section view of the elevator of FIG. 1.

FIG. 3 is an isometric view of the elevator of FIG. 1 with the elevator timing ring in an upward position.

FIG. 4 is an isometric view of the elevator of FIG. 1 with the elevator timing ring in a downward position.

FIG. 5 is a schematic side elevation view of the elevator of FIG. 1 suspended on a first selected pair of elevator lifting ears by lifting links having a load capacity and configuration corresponding to that of the first selected pair of lifting ears.

FIG. 6 is a schematic side elevation view of the elevator of FIG. 5 suspended on a second selected pair of elevator lifting ears by lifting links having a load capacity and configuration corresponding to that of the second selected pair of elevator lifting ears.

DESCRIPTION OF THE EMBODIMENT

FIGS. 1 through 4 show an embodiment of the dual ear elevator (10) of Applicant's invention. FIG. 1, a top view, shows the elevator (10) comprised of ring-shaped body (12) having a central circular opening (20). The body (12) is shown having a square external profile (11) but the external profile may be circular, rectangular, or any other suitable shape. Positioned within the central opening (20) is a pipe support assembly (22).

Attached to the body (12) are a plurality of pairs of hanger ears, shown as opposing hanger ears (14) and opposing hanger ears (16). Each of the opposing hanger ears (14) is sized to support the maximum load capacity of the elevator (10) and is shaped to match with a corresponding lifting link (L1) supported on a draw-works assembly of a drilling rig. The lifting links (L1) are sized and configured to have the same maximum load capacity as the corresponding hanger ears (14) and elevator (10). Each of the opposing hanger ears (16) are sized to support a desired secondary lessor load capacity of the elevator (10) and are shaped to match with a corresponding lifting link (L2) supported on a draw-works assembly of a drilling rig. The lifting links (L2) are sized and configured to have the same load capacity as the corresponding hanger ears (16).

FIG. 2 is a vertical cross-section view of the elevator (10) cut along lines A-A of FIG. 1. As shown in FIG. 2, opposing first hanger ears (14) have a shape and profile (14a) that prevents attachment of lift links having a rated load capacity less than the rated load capacity of hanger ears (14). Each hanger ear (14) is provided with a detachable ear guard (15) to further prevent the attachment and use of lifting links having a rated load capacity less than the rated load capacity of ears (14). Similarly, opposing second hanger ears (16) have a shape and profile (16a) that prevents attachment of lifting links having a greater rated load capacity than the rated load capacity of ears (16). Each hanger ear (16) is also provided with a detachable ear guard (17) to further prevent the attachment and use of lifting links having a rated load capacity greater that the rated load capacity of ears (16). The ear guards (15) and (17) will serve to prevent detachment of the hanger ears from the corresponding lifting links that may cause the elevator (10) to malfunction or be dropped from the lifting links. Ear guards (15) and (17) may be attached and detached from the hanger ears (14) and (16) by insertion and removal of bolts (13) as shown in FIG. 3 or by a insertion and removal of a key (19a) from keyway (19b) of a latch and key mechanism (19) shown in FIG. 4.

The pipe support assembly (22), best seen in FIGS. 2-4, is comprised of a plurality of vertically oriented inwardly tapered slip carrier plates (24) arrayed around the internal periphery of the central opening (20) of the body (12). Each of the slip carrier plates (24) slidably supports a tapered slip (26) that is attached to a timing ring (27) by linkage (23). The slips (26) may have at least one pipe gripping die (28) attached to each slip (26), though multiple pipe gripping dies (28) may be stacked vertically long each slip (26) as shown. The dies (28) may have a pipe engagement surface (28a) that is smooth as shown or surface (28a) may have a plurality of gripping teeth. The pipe engagement surface (28a) of the dies (28) may also be V-shaped as shown and arranged as described in Applicants U.S. Pat. No. 7,775,270. The carrier plates (24) and the slips (26) may be configured with machine slides (29) such as interconnecting dovetail slides or T-slot slides to facilitate movement of the slips (26) on the slip carriers (24).

A plurality of hydraulic cylinders (25), or other similar liner actuators, each having an extendable and retractable piston rod (25a) is mounted between the body (12) and timing ring (27). Extension and retraction of the piston rod (25a) moves the timing ring (27) upward and downward which then, by means of the attaching linkage (23), slides the slips (26) vertically upward and downward on the inwardly tapered surfaces of the tapered vertical carrier plates (24). This upward and downward movement of the slips (26) along the tapered surface of the carrier plates causes the slips (26) to move horizontally and radially inward and outward with respect to the central opening (20) of the elevator body (12).

FIG. 5 and FIG. 6 show the elevator (10) suspended from lifting links of a hoist line of a travelling block attached to the draw-works of a rig derrick in use to support pipe segment (P). As shown in FIG. 5 opposing hanger ears (16) have been selected from the group of hanger ears (14) and (16) of the elevator (10) and the selected hanger ears (16) have been attached to links (L2) selected to correspond to the size and working load capacity of selected hanger ears (16). Ear guards (17) were detached to allow lifting links (L2) to be placed in fitted support contact with profile (16a) of first hanger ears (16) and reattached to guard against detachment of links (L2). If the shape of lifting links (L2) does not properly fit within guard (17) or upon profile (16a), it will be an indication of improper combination of lifting link (L2) with hanger ear (16). The distinguishing profile (16a) of hanger ears (16) and shape of guards (17) serves to prevent an improper combination and mounting of hanger ears (16) with lifting links (L2).

The piston rods (25a) of the hydraulic cylinders (25) are then extended as shown in FIG. 3 to lift the timing ring (27) of gripping assembly (22) to move the slips (26) upward on the slip carrier plates (24) and horizontally outward from the central opening (20) of the elevator body (12) to allow a pipe segment (P) to be inserted into the central opening of the elevator (10). After the pipe segment (P) enters the central opening (20) of the elevator body (12), piston rods (25a) of the hydraulic cylinders (25) are retracted to lower the timing ring (22), causing slips (26) as shown in FIG. 4 to move downward on the slip carrier plates (24) and radially inward into the central opening (20) of the elevator body to hold pipe segment (P) with the dies (28).

Lifting links (L2) are lifted by the draw-works to raise the attached elevator (10) on the hangers (16) and the pipe segment (P). The weight of the pipe segment (P) on the slips (26) further forces slips (26) downward along the inwardly tapered surfaces of the slip carrier plates (24) to secure the grip of dies (28) upon pipe segment (P). Pipe segment (P) may then be moved into a desired position for attachment to a wellbore pipe string. After pipe string (P) is threadedly attached to the wellbore pipe string, piston rods (25a) of the hydraulic cylinders (25) are extended as shown in FIG. 3 to move the slips (26) upward along the slip carrier plates (24) and radially outward from the central opening (20) of the elevator body (12) to release pipe segment (P) to allow pipe segment (P) to be removed from the central opening of the elevator (10).

Should well operations require the elevator to support a pipe load greater than the maximum working load of lifting links (L2) and second hanger ears (16), lifting links (L2) may be removed from hanger ears (16) by reversing the attachment process to allow transition to first hanger ears (14) and lifting links (L1) as shown in FIG. 6 to provide a greater load capacity. The process of attaching lifting links (L1) and hanger ears (14) is the same as that described for attachment of lifting ears (16) to lifting links (L2).

While this invention has been particularly shown and described with references to a preferred embodiment, it will be understood by those skilled in the art that such depiction is merely exemplary of the present invention and that various modifications and improvements may be made invention o without departing from its spirit and the scope. For example, the above described embodiment utilizes two pairs of opposing hanger ears that may be selected for attachment to selected lifting links. However, the elevator (10) may have other arrangements of hanger ears, such as three or four pairs of opposing hanger ears each having differing working load capacities to corresponding selected lifting links, that may be used to support the elevator (10) with a supported pipe segment.

Claims

1. An elevator for support a length of pipe comprising:

(a) a body; and

(b) at least two pairs of hanger ears attached to said body, each said pair of hanger ears configured to have a different maximum load capacity.

2. The elevator recited in claim 1 wherein each hanger ear of said pair of hanger ears is configured to match with a selected corresponding lifting link.

3. The elevator recited in claim 2 wherein said selected corresponding lifting link has a load capacity less than or equal to the load capacity of said matching hanger ear.

4. The elevator recited in claim 3, further comprising ear guards upon each said pair of hanger ears.

5. The elevator recited in claim 4 wherein each said hanger ear has a shape and a profile that prevents attachment of a non-corresponding lifting link.

6. The elevator recited in claim 5 wherein said ear guards on said hanger ears prevent the attachment of a non-corresponding lifting link.

7. The elevator recited in claim 3 further comprising a pipe support assembly.

8. The elevator recited in claim 7 wherein said pipe support assembly is comprised of a plurality of extendable and retractable slips and wherein at least one pipe gripping die is mounted on each of said slips.

9. A pipe elevator comprising:

(a) a body:

(b) a first pair of hanger ears attached to said body, said first pair of hanger ears sized to support a desired maximum load capacity; and

(c) a second pair of hanger ears attached to said body, said second pair of hanger ears sized to support a desired secondary load capacity.

10. The pipe elevator recited in claim 9, wherein:

(a) said ears of said first pair of hanger ears are shaped to match with a pair of lifting links sized and configured to correspond with the load capacity of said first pair of hanger ears; and

(b) said ears of said second pair of hanger ears are shaped to match with a pair of lifting links sized and configured to correspond with the load capacity of said second pairs of hanger ears.

11. The pipe elevator recited in claim 10, further comprising ear guards positioned on each said ear of said first and second pair of hanger ears.

11. The pipe elevator recited in claim 11 wherein said body is ring-shaped to provide a central opening for receiving a pipe segment.

13. The pipe elevator as recited in claim 12, further comprising:

(a) a plurality of slips distributed peripherally about said central opening of said ring-shaped body;

(b) a plurality of pipe gripping dies distributed on each said slip;

(c) a timing ring;

(d) a linkage attaching each said slip to said timing ring; and

(e) a plurality of hydraulic cylinders mounted to said body, said hydraulic cylinders having an extendable and retractable piston rod attached to said timing ring.

14. The pipe elevator as recited in claim 13 wherein each said slip of said plurality of slips is slidably mounted upon a vertically oriented inwardly tapered plate.

15. The pipe elevator as recited in claim 14 wherein said gripping dies have a V-shaped pipe engagement surface.

16. A method of for attaching a pipe segment to a wellbore pipe string comprising the steps of:

(a) providing a pipe elevator having at least two pairs of hanger ears, each said pair of hanger ears having a different maximum load capacity;

(b) selecting a first pair of hanger ears of a desired load capacity from said provided pairs of hanger ears;

(c) providing a plurality of sets of lifting links, said pairs of lifting links configured to have a different load capacity;

(d) selecting a first set of lifting links, said first set of lifting links having a load capacity matching said desired load capacity of said first selected pair of hanger ears;

(e) attaching said first set of lifting links to said first selected pair of hanger ears; and

(f) raising said first set of lifting links thereby lifting said elevator on said first selected pair of hanger ears whereby a pipe segment is supported on said elevator.

17. The method of claim 16, further comprising the additional steps of:

(a) detaching said first set of lifting links from said first selected pair of hanger ears;

(b) selecting a second pair of hanger ears from said provided pairs of hanger ears;

(c) selecting a second set of lifting links from said provided plurality of sets of lifting links, said second set of lifting links having a load capacity matching said load capacity of said second selected pair of hanger ears;

(d) attaching said second set of lifting links to said second selected pair of hanger ears; and

(e) raising said second set of lifting links thereby lifting said elevator on said second selected pair of hanger ears whereby a pipe segment is supported on said elevator.

18. The method of claim 17 wherein said pipe elevator has a pipe support assembly comprising:

(a) a plurality of slips distributed peripherally about a central opening in said elevator;

(b) a plurality of pipe gripping dies distributed on each said slip;

(c) a timing ring;

(d) a linkage attaching each said slip to said timing ring; and

(e) a plurality of hydraulic cylinders mounted to said body, said hydraulic cylinders having an extendable and retractable piston rod attached to said timing ring whereby extension and retraction of said piston rod will move said plurality of slips to hold and release said pipe segment.