CN117581005A

CN117581005A - Lowering and recovering tool

Info

Publication number: CN117581005A
Application number: CN202280046058.2A
Authority: CN
Inventors: 乔治·詹姆斯·米乔德; 斯图尔特·乔治·威尔逊; 查尔斯·厄尔·诺维拉; 科林·沃尔特·布洛克; 杰夫·斯坎德斯
Original assignee: Beyond Energy Service Technology Co
Current assignee: Beyond Energy Service Technology Co
Priority date: 2021-07-09
Filing date: 2022-07-07
Publication date: 2024-02-20
Also published as: GB202318983D0; AU2022306881A1; MX2024000412A; CA3124148A1; EP4367362A1; CA3222380A1; US20240271495A1; WO2023279192A1; GB2622176A

Abstract

A drop-recovery tool for oilfield operations, the tool comprising: a first section comprising a valve cover and a split retainer, the first section comprising a cavity having an inner diameter adapted to allow insertion of a second section therethrough, and wherein the first section is adapted to be secured to a tool (such as a bearing assembly); and the second section having an elongated body with an outer diameter smaller than an inner diameter of the first section, the second section comprising: a rail adapted to secure a holder, the holder extending from the split holder into the rail; an inlet channel adapted to receive the retainer on the first section; a release channel adapted to allow release of the retainer from the track; wherein the second section is adapted to be mounted on a drill string or the like and is releasably insertable into the cavity of the first section by inserting the holder into the track.

Description

Lowering and recovering tool

Technical Field

The present invention relates to a novel tool for the oil and gas industry, and more particularly to a novel drop-in-recovery tool.

Background

It is common practice to lower, place, set and retrieve downhole tools within a wellbore to perform various functions including sealing the wellbore or for transporting measurement devices to monitor parameters such as pressure or temperature within the well. Typically, wellbores are cased using drill pipe, casing, or tubing strings that are designed in a manner that provides a predetermined location for placement and setting of such downhole tools.

The running and retrieving tools commonly used in the industry have a J-slot profile that is widely used in the industry. However, the J-slot profile is not very user friendly because there is typically a process of lowering and rotating the tool when encountering the entry profile of the J-slot until the pin engaging the J-slot descends, then continuing to move down until the tool is stopped, then rotating again to engage the J-slot to retrieve the tool.

Other mechanisms used by Rotary Control Devices (RCDs) require the use of shear pins and subject the shear pins to shear forces as part of the function of the installation and retrieval tool. Again, this is not very user friendly and requires constant maintenance by the operator to replace the shear pins. There are other designs that use air or hydraulic pressure to actuate the tool from the surface via a hose and console. However, this adds time to the process, risk of the hose being squeezed, and unnecessary equipment and NPT costs.

The running tool is used to place and set other downhole tools in the well. Once the downhole tool is set in place, it may remain there for a period of time, ranging from hours to days. At the same time, the running tool is brought back to the ground surface.

Running and downhole tools have been designed to run, operate and retrieve using "wires" or single strands of non-power cables known as "slicklines". However, all of the drop-and-retrieve tools currently in use the same type of connection. These connections allow the running tool to safely transport the tool or assembly to a predetermined location, then release the tool and be brought back to the surface while the tool or assembly remains in place within the wellbore. Once it is time to retrieve the tool or component, the running tool will be run back downhole and attempt to "reconnect" with the tool at the connection point. In view of the type of connection used, it is necessary to navigate the running tool very precisely to engage the connection point and thus be able to remove the tool or component from its set-up position and lift it to the wellbore surface.

In view of the prior art regarding connections for drop-in-out tools, there remains a need to provide a more durable, user friendly connection. The present invention aims to overcome at least some of the disadvantages currently encountered.

Disclosure of Invention

The present invention overcomes some of the disadvantages of the prior art by providing a user-friendly drop-in-recovery tool that self-positions the J-pin to a complementary mating profile by simply moving the string up and down.

According to one aspect of the present invention there is provided a run-out-retrieve tool for oilfield operations, the tool comprising:

-a first section comprising a valve cover and a split retainer, the first section comprising a cavity having an inner diameter adapted to allow insertion of a second section therethrough, and wherein the first section is adapted to be secured to a tool (such as a bearing assembly); and

-the second section having an elongated body with an outer diameter smaller than an inner diameter of the first section, the second section comprising:

-a rail adapted to secure a holder extending from the split holder to the rail;

-an inlet channel adapted to receive the holder on the first section;

-a release channel adapted to allow release of the holder from the track;

wherein the second section is adapted to be mounted on a drill string or the like and is releasably insertable into the cavity of the first section by inserting the holder into the track.

According to a preferred embodiment of the invention, the retainer comprises a plurality of J-pins extending radially inwardly from the first section and adapted to fit within the track on the second section.

According to a preferred embodiment of the invention, the rail comprises an upper lifting shoulder and a lower shoulder and a channel therebetween, wherein the upper lifting shoulder and the lower shoulder are separable from each other upon application of pressure to the lower shoulder by the holder.

According to a preferred embodiment of the invention, the lower shoulder of the rail comprises a plurality of channel entry points adapted to guide a corresponding plurality of holders into the rail. Preferably, a plurality of said channels are funnel-shaped entry points.

According to a preferred embodiment of the invention, the upper lifting section of the track comprises:

-a plurality of sloped wall segments, wherein each sloped wall segment comprises a lower end and an upper end; and

-a nesting gap at the upper end of each of the plurality of diagonal wall segments;

wherein the nesting gap is adapted to secure the holder during operation when the tool is moved in a downward direction within the wellbore.

According to a preferred embodiment of the invention, the lower shoulder of the track will separate by movement longitudinally away from the upper lifting shoulder, thereby creating a plurality of release channels (exit points) associated with the respective holders to release the second section from the first section and leave the first section in a predetermined position within the wellbore, when sufficient pressure is applied to the lower shoulder during operation.

According to another preferred embodiment of the invention, the lower shoulder and the upper lifting shoulder comprise complementary nesting contours at the edges where they meet, which complementary nesting contours are adapted to hold the lower shoulder and the upper lifting shoulder in place during rotational movement of the drill string. Preferably, the complementary nesting profile comprises a zigzag pattern.

According to a preferred embodiment of the invention, the lower shoulder has a plurality of protrusions which combine with a plurality of complementary protrusions located in the lower part of the lifting shoulder of the track to form a plurality of said funnel-shaped entry points.

Preferably, the inlet channel comprises a first side member located on a first side of the inlet channel and a second side member located on a second side of the inlet channel, wherein each member is inclined towards the track inlet point. Preferably, the first side member is fixed, and wherein the second side member comprises: a fixed upper portion and a movable lower portion.

According to a preferred embodiment of the invention, the upper portion of the second side member is located at the upper lifting shoulder of the rail and the lower portion of the second side member is located at the lower shoulder of the rail.

According to a preferred embodiment of the invention, the nesting gap is a semi-circular opening adapted to secure the bearing assembly in place on the drop-in-take-up tool. Preferably, the retainer nesting gap is offset from the inlet channel.

According to a preferred embodiment of the invention, the nesting gap comprises a sloped wall on a first adjacent side to allow upward movement of the retainer to be directed along the channel towards the nesting gap. Preferably, the nesting gap comprises a wall parallel to the longitudinal axis of the drill string on the second adjacent side.

According to another aspect of the present invention there is provided a run-out-retrieve tool for oilfield operations, the tool comprising:

-the second section having an elongated body with an outer diameter smaller than the inner diameter of the first section;

wherein the first and second sections are releasably secured together in operation by engagement of a plurality of concentrically oriented J-pins on the first section with tracks on the second section.

According to a preferred description of the present invention, a running and retrieving tool is provided for deploying/retrieving a Bearing Assembly (BA) to/from a Rotary Control Device (RCD) housing in an offshore application. Preferably there is a dual redundancy safety feature that other tools cannot provide, i.e. when the RRT is pulled back to the derrick, the RRT cannot release itself and drop onto the rig due to the profile geometry of the rail and the split ring that requires around 10000 pounds of force to disengage the tool.

According to a preferred embodiment of the present invention there is provided a J-track lowering and retrieving tool which is compact, simple to operate, user friendly, and at the same time has the feature of improving its safety during operation.

According to a preferred embodiment of the present invention, a running-retrieving tool is provided that does not require clockwise or counter-clockwise rotation of the drill string for any reason, such as the need to connect or release the tool, but only up and down axial movement to perform all of the functions desired. With pressure control, with a conventional J-slot configuration, it may be necessary to reduce the annulus pressure to allow the drill string to rotate to align the J-slot with the tool, which may result in leakage between the drill pipe and the annulus. It is well known that the annulus is designed primarily for stripping applications in the case of pressure control, if desired. Since the present invention requires only axial movement, there is no longer a need to manipulate the annulus pressure to operate the tool, thereby increasing safety.

Drawings

The invention may be more completely understood in consideration of the following description of various embodiments of the invention in connection with the accompanying drawings, in which:

FIG. 1 is a side view of a prior art drop-in-take-off tool connection;

FIG. 2 is a side cross-sectional view of a drop-in-take-back tool connection according to a preferred embodiment of the present invention;

FIG. 3 is a close-up enlarged side cross-sectional view of the drop-in-take-back tool connection of FIG. 2 in accordance with a preferred embodiment of the present invention;

FIG. 4 is a perspective view of a valve cover and split retainer mounted on a bearing assembly in accordance with a preferred embodiment of the present invention;

FIG. 5 is a close-up enlarged perspective view of a valve cover and split retainer mounted on a bearing assembly in accordance with a preferred embodiment of the present invention;

FIG. 6 is a perspective view of a spindle comprising J-shaped rails in accordance with a preferred embodiment of the present invention;

FIG. 7 is a close-up enlarged perspective view of a spindle including a J-track in accordance with a preferred embodiment of the present invention;

FIG. 8 is a side view of a mandrel including J-rails mounted on a tubular body according to a preferred embodiment of the present invention;

FIG. 9 is a side view of a valve cover and split retainer with a bearing assembly mounted thereon and inserted onto a spindle containing a J-track in accordance with a preferred embodiment of the present invention;

fig. 10a to 10d are side views of a valve cover and J-track at various points of insertion of a J-pin into the J-track, according to a preferred embodiment of the present invention.

Detailed Description

According to a preferred description of the present invention, a running and retrieving tool is provided for deploying/retrieving a Bearing Assembly (BA) to/from a Rotary Control Device (RCD) housing in an offshore application. Preferably, it is compatible with 5-1/2 to 6-5/8 drill strings and 7-3/4 "or 9" through hole bearing assemblies. According to a preferred embodiment, all components are universal in these size ranges, except for the spindle, valve cover and centralizer.

Preferably, in operation, the tool pierces the bearing assembly with the box end of the spindle above the bearing assembly and the pin end of the spindle below the lower seal element of the bearing assembly. Both ends of the mandrel are threaded for direct connection to the drill string (100) as required by the customer. As the primary tensile load bearing component of the tool, the mandrel is designed and manufactured to meet or exceed the tensile strength of the drill string.

During deployment, the tool (50) supports the weight of the bearing assembly (60) by means of a locking ring. The locking ring is latched in a groove formed between the valve cover (3) and the split retainer (4). For assembly, the tool (50) is pierced through the bearing assembly (60) until the lower shoulder of the split J-profile contacts the stop exclusion zone of the valve cover. In this position, the split keeper (4) engages the top of the valve cover (3) to retain the locking ring (7) in the locked position.

As illustrated in fig. 8 and 9, the drill string (100) includes a running tool (50) (see fig. 8) and an RCD (60) mounted on a valve cover (3) and a split retainer (4) (see fig. 9) securing the running tool therein.

As illustrated in fig. 4 and 5, the valve cover (3) includes a split retainer (4), a plurality of evenly spaced and circumferentially positioned J-pins (8) that will form a connection between the valve cover and the split retainer (4). The valve cover (3) is also provided with a plurality of cup point set screws (14), a steel hanging ring (22), a threaded rod (11) and a nut (12) so as to fix the split type retainer (3) on the valve cover (3).

As illustrated in fig. 6 and 7, the running tool (50) comprises a split J-profile (10) consisting of two sections (10 a) and (10 b) which, in operation, are mutually locked by means of complementary saw-tooth profiles. The lowering tool is also provided with a lock ring (7), a J-shaped profile split type cap (6), a split type centralizer (1), a split type shearing ring (9), brass Niu Koutou (13) and a plurality of groups of different screws (15, 16, 17, 18, 20 and 21).

In operation, the running tool (50) is deployed by lowering the drill pipe (100) until the bearing assembly (60) is within the RCD housing. Once the bearing assembly (60) is secured within the RCD housing, the drill string (100) is lifted such that the locking collar (7) disengages the bearing assembly (60), which requires an over-tension of 10000 lbf. Lifting is continued until the J-pins (8) protruding radially inwardly through the valve cover (3) contact the lifting surface (40) of the split J-profile. At this time, the fixation of the bearing assembly (60) can be verified by overdrawing. The drill rod (100) is then lowered again until the lower shoulder (80) of the split J-profile contacts the stop exclusion zone of the valve cover. At this point, the J-shaped pin (8) has entered the release path of the J-profile. Finally, the drill string (100) is lifted and the J-track running tool (50) is extracted from the now deployed bearing assembly (60). Continuing to lift, the running tool (50) is returned to the drill floor where it can be disconnected from the drill string (100) and set aside for later use in retrieving the bearing assembly (60).

To retrieve the bearing assembly (60), the J-track running tool (50) is reattached to the drill string (100) and then lowered. The centralizer (1) of the mandrel (5) ensures sufficient concentricity before the split J-profile (10) of the J-track running tool enters the valve cap (3). Further lowering of the split J-profile (10) results in the J-pin (8) contacting the guide surfaces (1030 and 1032) of the split J-profile (10). When the J-pin (8) contacts the guide surfaces (1030 and 1032), the force exerted thereon forces the split J-profile (10) to rotate into a smooth alignment with the J-pin (8).

According to a preferred embodiment of the invention, the insertion point of the J-pin into the J-track is defined as a channel adapted to guide the J-pin from a first lower position located outside the J-track to a second higher position located inside the J-track. Preferably, the channel is provided with two members (one on each side of the channel), each member being inclined towards the insertion point, similar to a funnel. According to a further preferred embodiment, the channel comprises a first side member and a second side member, wherein said first side member is fixed and the second side member is movable. According to the embodiment illustrated in fig. 2-10, the second side member portion is positioned on the split J-profile lower shoulder and is separated from another portion of the second side member upon application of sufficient pressure to the split J-profile lower shoulder. After entry through the insertion point, the J-pin is guided to a nesting point where it is positioned in a semicircular opening adapted to secure the bearing assembly in place on the drop-in-take tool. The nesting point of the J-pins is preferably offset from the channel to prevent the tool from slipping off and losing the bearing assembly during the retrieval operation. Preferably, the J-pin is guided to the nesting point by a sloped wall that guides the movement of the J-pin obliquely to the nesting point. Preferably, on the other side of the nesting point, the wall is parallel to the length of the drill pipe.

According to the illustrated preferred embodiment, the second member is substantially aligned with the nesting point and is inclined downwardly so as to guide the J-pin towards a contact point, defined as the abutment of the lower portion of the second member of a channel with the first member of an adjacent channel, upon a release operation. During a release operation, the pressure exerted by the J-pin on the contact point will force the split retainer downward, preferably forcing the split retainer portion to rotate, causing the J-pin to release from the drop-retrieve tool and thus the bearing assembly from the drop-retrieve tool.

According to the illustrated preferred embodiment, the second member of a channel abuts the first member of an adjacent channel, thereby guiding an adjacent J-pin into the adjacent channel.

According to a preferred embodiment of the present invention, as illustrated in fig. 10 a-10 d, the insertion point of the J-pin into the J-track (1020) is defined as a channel (1010) adapted to guide the J-pin (8) from a first lower position (as shown in fig. 10 a) located outside the J-track to a second higher position (as shown in fig. 10 b) located inside the J-track (1020). Preferably, the channel (1010) is provided with two members (one on either side of the channel) (1030 and 1032), each member being inclined towards the insertion point, similar to a funnel. According to yet another preferred embodiment, the channel (1010) comprises a first side member and a second side member, wherein said first side member (1030) is fixed, and wherein said second member is composed of two parts, a fixed upper part (1034) and a movable lower part (1036). According to the embodiment illustrated in fig. 2 to 10, the second member (1032) is composed of two parts (1034 and 1036). A lower portion (1036) of the second side member (1032) is located on the split J-profile lower shoulder and is separated from another portion (1034) of the second member (1032) upon application of sufficient pressure to the split J-profile lower shoulder. After entering through the insertion point (channel (1010)), the J-pin (8) is guided to a nesting point (or nesting gap) (1040) where the J-pin (8) is located in a semicircular opening adapted to secure the bearing assembly in place on the drop-and-retrieve tool. The J-pin (8) nesting gap (1040) is preferably offset from the channel (1010) to prevent the tool from slipping off and losing the bearing assembly during the retrieval operation. Preferably, the J-pin (8) is guided to the nesting gap (1040) by a sloped wall (1050) that slantingly guides the movement of the J-pin (8) up through the channel toward the nesting gap (1040). Preferably, on the other side of the nesting gap (1040), the wall (1060) is parallel to the length of the drill string or drill pipe.

According to the illustrated preferred embodiment, the second member (1032) is substantially aligned with the nesting gap (1040) and is inclined downwardly so as to guide the J-pin (8) towards a contact point (1070) defined as the abutment of the lower portion (1036) of the second member (1032) of a channel (1010) with the first member (1030) of an adjacent channel, upon a release operation (see fig. 10c and 10 d). During a release operation, the pressure exerted by the J-pin (8) at the contact point (1070) will force the split retainer (4) downward, preferably forcing the split retainer (4) to partially rotate, thereby forming a release channel (1080), resulting in release of the J-pin (8) from the drop-retrieve tool and thus release of the bearing assembly from the drop-retrieve tool (50).

The continued lowering action causes the locking ring (7) to be in latching engagement with the split keeper (4), and finally the lower shoulder (10 b) of the split J-profile contacts the stop exclusion zone (# #) of the valve cover to be lifted. According to a preferred embodiment of the invention, the force required to extract the bearing assembly (60) from the RCD housing would normally not exceed 10,000 lbf, i.e. the release force of the lock ring (7), and thus the bearing assembly (60) would be transported to the ground surface with the lock ring supporting the weight of the Bearing Assembly (BA). If the extraction force of the bearing assembly (60) exceeds 10,000 pounds force, the lock ring (7) will disengage the split retainer (4) and the J-pin (8) will then contact the split J-profile lifting surface (40). In this position, the required extraction force will be transferred from the lifting surface (40) of the split J-profile to the J-pin (8). The bearing assembly (60) is withdrawn from the RCD housing and conveyed back to the drill floor as long as the required withdrawal force does not exceed the shearing capacity of the preconfigured split shear ring (9). If the extraction force exceeds the shearing capacity of the split shear ring (9), the split shear ring (9) will shear downward and rotate away from the J-pins (8), allowing the J-track lowering tool (50) to be conveyed back to the drill floor. Once returned to the drill floor, the operator can re-fix the split shear ring (9) with greater shear capacity (more and/or stronger shear elements) and then another recovery attempt can be made.

According to a preferred embodiment illustrated in fig. 2 to 10, the lifting surface (40) of the upper portion (10 a) of the split J-profile (10) comprises semi-circular holes adapted to receive the J-pins (8) and to temporarily lock the J-pins in place when pressure is applied upwards into the respective holes by the J-pins during the lifting operation. This nested shape arrangement greatly reduces the risk of the J-pin slipping out of position and rotation when the bearing assembly (60) is pulled out of the drill hole, and the subsequent risk of the bearing assembly (60) being lost.

According to a preferred embodiment of the invention, the tool does not need to rotate the drill string clockwise or counter-clockwise for any reason, but rather moves strictly axially up and down to perform all functions.

With pressure control, with a conventional J-slot configuration, it may be necessary to reduce the annulus pressure to allow the drill pipe to rotate to align the J-slot with the tool, which may result in leakage between the drill pipe and the annulus. As is well known in the art, the annulus is designed primarily for stripping applications in pressure control situations, if desired. According to a preferred embodiment of the invention, there is no need to manipulate the annulus pressure to operate the tool, since only axial movement is required, thereby increasing the safety factor.

Description of the techniques

According to a preferred embodiment of the invention, the J-track lowering tool consists of the following main components: a valve cover; a split holder;

according to a preferred embodiment of the invention, the valve cover functions to attach to the top of the bearing assembly and provide an interface for deploying and retrieving the Bearing Assembly (BA). Typically, the valve cover is made of alloy steel and is surface nitrided. In the embodiment described above, it weighs about 230 pounds.

According to a preferred embodiment of the invention, the function of the split retainer is to secure to the top of the valve cover where it forms an internal recess in which the locking ring will lock and unlock during deployment and retrieval operations. Typically, according to the present embodiment, the split retainer is made of alloy steel, surface nitrided.

According to a preferred embodiment of the invention, the function of the J-pin is to transfer axial loads between the valve cover and the split J-profile. Typically, according to this embodiment, the J-pins are made of alloy steel, surface nitrided.

According to a preferred embodiment of the invention, the function of the mandrel is to provide means for connecting the running tool to the drill string. Typically, according to this embodiment, the mandrel is made of alloy steel, the surface of which is treated with a Rilcoat coating (only the central body region).

According to a preferred embodiment of the invention, the function of the split centralizer is to improve concentricity/alignment prior to tool penetration. Typically, according to this embodiment, the split centralizer is made of aluminum.

According to a preferred embodiment of the present invention, the function of the J-profile split cap is to capture the locking ring. Typically, according to this embodiment, the J-profile split cap is made of alloy steel, surface nitrided.

According to a preferred embodiment of the invention, the function of the lock ring is to prevent the J-profile from cycling during deployment until the bearing assembly is in place; and reducing J-pin wear and bearing damage during the reclamation operation. Typically, according to this embodiment, the locking ring is made of alloy steel, the surface of which is treated with a rilcooat 4 coating.

According to a preferred embodiment of the invention, the function of the split J-profile retainer is to provide a load bearing surface for lifting the bearing assembly via the J-pins. Typically, according to this embodiment, the split J-profile retainer is made of alloy steel, surface nitrided.

According to a preferred embodiment of the invention, the split shear ring may provide an emergency means for extracting the tool from the bearing assembly. Preferably, there are 10 available positions, allowing for the installation of 2, 4, 6, 8 or 10 shear screws. Typically, according to this embodiment, the split shear ring is made of alloy steel, surface nitrided.

According to a preferred embodiment of the invention, the 5/8"-11,0.75" long button head screw functions as a shearing element. Typically, according to this embodiment, the button head screw of the split holder is made of brass or alloy steel.

Although the foregoing invention has been described in some detail for purposes of clarity and understanding, once the disclosure is familiar to those skilled in the relevant art, it will be recognized that various changes in form and detail can be made therein without departing from the true scope of the invention as defined by the following claims.

Claims

1. A drop-recovery tool for oilfield operations, the tool comprising:

-a track adapted to secure a holder extending from the split holder into the track;

-an inlet channel adapted to receive the holder on the first section;

-a release channel adapted to allow release of the holder from the track;

2. The drop-and-retrieve tool of claim 1, wherein the retainer comprises a plurality of J-pins extending radially inward from the first section and adapted to fit within the track on the second section.

3. The drop-and-retrieve tool of claim 1 or 2, wherein the track includes upper and lower lifting shoulders and a channel therebetween, wherein the upper and lower shoulders are separable from each other upon application of pressure to the lower shoulder by the retainer.

4. The drop-and-retrieve tool of claim 3, wherein the lower shoulder of the track includes a plurality of channel entry points adapted to guide a corresponding plurality of holders into the track.

5. A drop-and-retrieve tool as in claim 3, wherein a plurality of said channels are funnel-shaped entry points.

6. The drop-and-retrieve tool of claim 1, wherein the upper lifting section of the track comprises:

7. The drop-and-retrieve tool of any of claims 1-6, wherein, during operation, when sufficient pressure is applied to the lower shoulder of the track, the lower shoulder will separate by movement longitudinally away from the upper lifting shoulder, creating a plurality of release channels (exit points) associated with the respective retainers to release the second section from the first section and leave the first section in a predetermined position within the wellbore.

8. The running-retrieval tool of any one of claims 1 to 7, wherein the lower shoulder and the upper lifting shoulder include complementary nesting contours at the edges where they meet, the complementary nesting contours adapted to hold the lower shoulder and upper lifting shoulder in place during rotational movement of the drill string.

9. The drop-and-retrieve tool of claim 8, wherein the complementary nesting profile comprises a zigzag pattern.

10. The drop-and-retrieve tool of any of claims 1-9, wherein the lower shoulder has a plurality of protrusions that combine with a plurality of complementary protrusions located under a lifting shoulder of the track to form a plurality of the funnel-shaped entry points.

11. The drop-and-retrieve tool of any of claims 1-10, wherein the inlet channel includes a first side member located on a first side of the inlet channel and a second side member located on a second side of the inlet channel, wherein each member is inclined toward a track entry point.

12. The drop-and-retrieve tool of any of claims 1-11, wherein the first side member is stationary, and wherein the second side member comprises: a fixed upper portion and a movable lower portion.

13. The drop-and-retrieve tool of any of claims 1-12, wherein the upper portion of the second side member is located at the upper lifting shoulder of the track and the lower portion of the second side member is located at the lower shoulder of the track.

14. The drop-and-retrieve tool of any of claims 1-13, wherein the nesting gap is a semi-circular opening adapted to secure a bearing assembly in place on the drop-and-retrieve tool.

15. The drop-and-retrieve tool of any of claims 1-14, wherein the retainer nesting gap is offset from the inlet channel.

16. The drop-and-retrieve tool of any of claims 1-15, wherein the nesting gap includes a sloped wall on a first adjacent side to allow upward movement of the retainer to be directed along a channel toward the nesting gap.

17. The running-retrieval tool of any one of claims 1 to 16, wherein the nesting gap includes a wall parallel to a longitudinal axis of the drill string on a second adjacent side.

18. A drop-recovery tool for oilfield operations, the tool comprising: