Field of the Invention

The present invention relates to a device and a system for lifting holding and lowering casing joints and assembled casing strings.

Background

In down-hole drilling and extraction processes, casing, also called tubulars or piping, is run down the wellbore for the purposes of drilling, performing operations or producing oil from the well. Casing is made up by connecting multiple threaded casing sections together and feeding them into the wellbore. Typically, casing sections have a tapered female thread at one end and a tapered male thread at the other end. The male end of a first casing section is threaded into the female end of a second casing section to makeup the casing string. Rotation of the first casing into the second casing is conducted until the tapered ends engage one another.

A typical system making up casing strings includes an elevator assembly housing a related gripping assembly and connected directly or indirectly to a travelling block, a flush mount or top mount spider, each having its own dedicated gripping assembly, connected directly or indirectly at the rig floor.

A typical procedure for making up casing strings involves picking up a new joint of casing to be made up by the elevator assembly. The elevator assembly is raised to raise the casing joint into position above a casing string to be made up, the casing string being gripped in place by a flush mount or top mount spider. The elevator assembly is then lowered so that the male thread of the casing joint is engaged with the female thread of the uppermost casing of the casing string.

The threads between the new casing joint and the uppermost casing of the casing string are then made up. The elevator then grips the new casing joint and is picked up to transfer the weight of the newly made up connection from the flush mount or top mount spider, so that the spider can be released. The elevator assembly then lowers the newly made up connection to the rig floor, which is then gripped again by the spider. The elevator assembly is then lowered, transferring the load to the spider, then the elevator is released and is prepared to pick up the next casing joint to be made up.

A reverse procedure is practiced for breaking out casing joints from a casing string. Elevators and spiders conduct a number of complex operations and are typically made up of numerous moving and working parts. These tools must be able to carry large loads while gripping the casing joint to be made up, and the casing string. It must be easily operated and rapidly maintainable during wellbore operations.

A constant need and interest therefore exists in the art to develop improved casing handling tools.

Summary

A tubular handling tool is provided for use as an elevator, comprising one or more slips movably retained by an upper ring and a lower ring, wherein the one or more upper rings and the one or more lower rings provide constraint against radial expansion forces. A frame for a tubular handling tool is further provided for use as an elevator comprising an upper ring and a lower ring in a vertically spaced relationship to one another and each having a central opening for receiving a casing section; and one or more removable means for connecting the upper ring and the lower ring and attaching the frame to a top drive or travelling block.

A tubular handling tool is further provided for use as a top mount spider comprising one or more slips movably retained by one or more upper rings and one or more lower rings, wherein the one or more upper rings and the one or more lower rings provide constraint against radial expansion forces.

A tubular handling tool is further provided for use as a flush mount spider comprising one or more slips movably retained by one or more upper rings and one or more lower rings.

A slip is further provided comprising a removable sliphead. Brief Description of the Drawings

The present invention will now be described in greater detail, with reference to the following drawings, in which: Figure 1 is an isometric view of one example of the elevator of the present invention;

Figure 2 is a cross-sectional view of one example of the elevator of the present invention;

Figure 3 is a top plan view of one example of the elevator of the present invention;

Figure 4 is an isometric view of a clevis pin of a present invention; Figure 5 is a cross-sectional elevation view of a clevis pin of the present invention;

Figure 6 is an isometric of one example of the top mount spider of the present invention;

Figure 7 is a cross-sectional view of one example of the top mount spider of the present invention; Figure 8 is a top plan view of one example of the top mount spider of the present invention;

Figure 9 is an isometric view of one example of the flush mount spider of the present invention;

Figure 10 is a cross section view of one example of the flush mount spider of the present invention;

Figure 11 is a top plan view of one example of the flush mount spider of the present invention;

Figure 12 is a first isometric view of one example of a slip and a die carrier of the present invention; Figure 13 is a second isometric view of one example of a slip and a die carrier of the present invention;

Figure 14 is an isometric view one example of a sliphead of the present invention.

Figure 15a is a first detailed view of a segment of the present modular gripping assembly, showing the actuator timing plate and slip head; Figure 15b is a second cross sectional detailed view of a segment of the present modular gripping assembly, showing the actuator timing plate and slip head; and

Figure 16 is a perspective view of one embodiment of a typical operational setup using a number of tools of the present invention.

Description of the Invention

The present invention relates to device and a system for supporting, raising and lowering casing strings. The present invention more specifically relates to an elevator, a top mount spider and a flush mount spider (FMS) and their related gripping assemblies.

With reference to Figures 1, 2 and 3, the present elevator 2 comprises one or more upper rings 4 and one or more lower rings 6 having multiple slip frames 8 supported by the upper rings 4 and lower rings 6 and arranged around the elevator 2. The upper rings 4 and lower rings 6 also preferably provide radial constraint to the components inside the elevator 2, such that the elevator 2 can withstand the radially expanding forces typically seen due to the axial loads experience by the elevator when lifting and lowering the casing string.

A slip 10 may be slidingly received into each of said slip frames 8. An insert carrier 12 may then be attached to each of said slips 10. An actuator timing plate 14 connects to a sliphead 16 at an upper end of each slip 10, and further connects to one or more cylinders 15 that are raised or lowered to actuate setting and releasing of the elevator 2 on the casing sections.

A lowermost of the present lower rings 6, preferably serves two purposes. It bears the load of elevator 2 including the casing string weight and preferably also it acts as a stabbing bell 6A, which partially guides and aligns the casing section into the elevator 2. The present design avoids the need of including an additional set of stabbing bells that then must be separately mounted on the elevator 2. A reducer may further be used in conjunction with the stabbing bell 6A, to accommodate smaller diameter casing.

Optionally, removable lifting ears can be connectable to the elevator 2 to connect indirectly with a travelling block.

With reference to Figures 4 and 5, more preferably, the lifting ears of the elevator 2 are in the form of a clevis assembly with pins 22. The clevis assembly 22 of the present invention are preferably non-integral to the elevator 2 and are preferably made from a plate or bar material. The clevis assembly 22 is removably attached to the elevator 2 by inserting a lower end of the clevis pin through the upper rings 4 and lower rings 6 and locking the lower end in place by a retaining means 24 preferably in the form of a retaining nut or any other suitable and well known means of securing the lower end of the clevis assembly 22 to the elevator 2. Further preferably the lower end of the clevis assembly 22 is machined with a profile to accommodate a split load ring 26 between a lower face of the lower ring 6 and the retaining nut 24. The split load ring 26 acts to absorb and distribute a portion of the load from the casing string, to lessen wear on the lower end of the clevis assembly 22.

An upper end of the clevis assembly 22 is preferably forked with a bail retainer pin 28 that can be locked onto the bails of a top drive or to a travelling block.

Figures 6, 7 and 8 illustrate one embodiment of a top mount spider 18 of the present invention. It has a series of upper rings 104 and lower rings 106 that provide radial constraint to the components inside the top mount spider 18, such that the top mount spider 18 can withstand the radially expanding forces typically seen during make up and break out operations. More preferably, the upper rings 104 and lower rings 106 each take the form of one or more split rings, rotatably connected at a first end by a hinge 162 and secured together at a second end to form full rings.

Multiple slip frames 108 supported by the upper rings 104 and lower rings 106 and arranged around the top mount spider 18. A slip 110 is slidingly received into each of said slip frames 108, and an insert carrier 112 is supported on each of said slips 110. An actuator timing plate 114 connects to a sliphead 116 at an upper end of each slip 110, and further connects to one or more cylinders 115 to actuate setting and releasing of the top mount spider 18 on the casing string at the well floor.

More preferably a lowermost ring of lower ring 106 is formed with one or more key slots 107 that align matching key slots 109 at a lower end of slip frames 108.

Preferably, a locking plate (not shown) slides through these key slots 107, 109 and holds the slip frame 108 to the lower rings 106.

With reference to Figures 9, 10 and 11, a flush mount spider 60 of the present invention is shown. The flushmount spider 60 has a singular upper ring 204 and a lower ring 206 having multiple slip frames 208 supported by the upper ring 204 and lower ring 206 and arranged around the flush mount spider 60. A slip 210 is slidingly received into each of said slip frames 208, and an insert carrier 212 is supported on each of said slips 210. An actuator timing plate 214 connects to a sliphead 216 at an upper end of each slip 210, and further connects to one or more cylinders 215 to actuate setting and releasing of the flush mount spider 60 on the casing string at the well floor.

More preferably the lower ring 206 is formed with one or more key slots 207 that align matching key slots 209 at a lower end of slip frames 208. Preferably, a locking plate (not shown) slides through these key slots 207, 209 and holds the slip frame 208 to the lower rings 206.

One or more support shoulders or lugs 20 extend radially from the upper ring 204, to engage with a rotary table, such that the flush mount spider 60 can be seated into the rotary table (not shown).

With reference to Figures 12 and 13, the slips 10, 110, 210 of the present invention are preferably slidingly received in the slip frames 8, 108, 208 and rotationally constrained by engagement of the side edges of the slips 10,110,210 with shoulders of the slip frames 8,108,208.

Guide means 32, preferably in the form of a mating profiles formed on the side edges of the slip 10,110,210 and the slip frames 8,108,208, guide the slips radially outwardly when raised and radially inwardly when lowered by actuation of the cylinders 15,115,215. Most preferably, guide means 32 take the form of a tongue and groove system that comprises either a tongue formed on the side edges of the slip 10, 110, 210 and a groove formed on the shoulders of the slip frame 8, 108, 208 or vice versa

The insert carrier 12, 112, 212 of the present invention provides a unique means of carrying one or more dies 30, 130,230 on the insert carrier 12, 112, 212, which can in turn be easily removed from the slip 10, 110, 210 and replaced. This allows for rapid change out of the dies 30, 130, 230 should they be come worn or damaged, and eliminates the need for removing individual dies from a slip 10, 110, 210. A slot and tab profile 34, 134, 234 on the slip 10, 110, 210 and die carrier 12, 112, 212 acts as a means to radially retain the insert carrier 12, 112, 212 within the slip 10, 110, 210.

The inner face of slips 8,108,208 of the present invention are most preferably formed with a vertical upper surface 38, 138, 238 and an inclined lower surface 40, 140, 240 on the inner face of the slip 10, 110, 210. A shoulder 36, 136, 236 exists between the vertical upper surface 38, 138, 238 and the inclined lower surface 40, 140, 240. The outer face of the insert carrier 12, 112, 212 of the present invention are most preferably formed with a vertical upper surface 50, 150, 250 and an inclined lower surface 52, 152, 252 of. A ledge 48, 148, 248 is formed at the intersection of the vertical upper surface 50, 150, 250 and the inclined lower surface 52, 152, 252.

Axial loads from the casing section or casing string are preferably transferred into the mating inclined lower surfaces 40, 140, 240 of slip 10,110, 210 and inclined lower surfaces 52, 152, 252 of the insert carrier 12, 112, 212. These mating lower inclined surfaces serve to support a portion of the axial load of the casing section or string and transfer some of the load bearing burden away from a thinner toe end of the slip 10, 110, 210 to a thicker upper portion of the slip 10, 110, 210. A portion of the axial load is also preferably carried in the shoulder 36,136,236 of the upper surface of the

38,138,238 of the slip. This advantageously transfers some load away from a somewhat thinner lower inclined surface 40,140,240 to the somewhat thicker upper surface 38,138,238.

A singular retaining means 46,146,246 serves to retain the dies 30 to the insert carrier. Most preferably the singular retaining means takes the form of a singular die and insert carrier retainer plate 46, 146, 246 that is screwed, bolted or otherwise suitably removably attached to a top surface of the insert carrier 12, 112, 212. The retainer plate 46, 146, 246 can be easily removed for inspection or replacement of the die 30, 130, 230 or insert carrier 12, 112, 212 without the need for removing separate plates for the die carrier and for the die.

With reference to Figure 14, a sliphead 16, 116, 216 is preferably separately machined and bolted to the slip 10, 110, 210. Unlike slip heads that are traditionally casted or welded to a slip, the present sliphead 16, 116, 216 can easily be disconnected to service the slip 10, 110, 210 or insert carrier 12, 112, 212.

Figures 15a and 15b show further details of a preferred embodiment of the present actuator timing plate 14, 114, 214 and sliphead 16, 116, 216. Each sliphead 16,116, 216 is preferably machined separately to the slip 10, 110, 210 itself and removably affixed to an upper end of each slip 10,110, 210. The sliphead 16,116, 216 preferably comprises one or more rollers or cam followers 42, 142, 242 or more preferably one or more pairs of rollers or cam followers 42,142, 242 in an axially spaced arrangement with one another. The cam followers 42, 142,242 are rollably received in one or more cam follower caps 44,144, 244 located around the actuator timing plate 14, 114, 214. The actuator timing plate 14, 114, 214 is further connected to one or more cylinders (not shown) to actuate setting and releasing of the slips 10, 110, 210 on the casing sections or the casing string. To set the slips 10, 110, 210 on the casing sections or casing string, the cylinders push the actuator timing plate 14, 114, 214 down. This in turn leads the slips 10, 110, 210 to travel both downwardly and radially inwardly along slip frames 8, 108, 208. Radial movement of the slips 10, 110, 210 is accommodated in the actuator timing plate 14, 114, 214 by corresponding radial movement of the cam followers 42, 142, 242 inside the cam follower caps 44, 144, 244.

In a typical operation, as illustrated in Figure 16, the present elevator assembly 2 and other optional devices are attached directly or indirectly to a travelling block. The elevator 2 is then lowered to a position near the rig floor to permit single joint elevator 200 to pick up a new joint of casing that has been raised from a pipe rack adjacent to the rig.

The elevator 2 is raised, coupled to the single joint elevator 200 by two of the four elevator support bars 3 to thereby pull the casing joint up and along the rig's v-door ramp until it is raised above the existing casing string, set in a flush mount spider 60 or a top mount spider 18.

The elevator 2 is lowered to allow the male thread of the casing joint to engage the female thread of the uppermost casing of the casing string.

The threads are then made up between the new casing joint and the uppermost casing of the casing string, set in the flush mount spider 60 or top mount spider 18.

Once made up, the single joint elevator 200 is released and the slips 10 in elevator 2 are set. The weight of the entire casing string, previously supported by a flush mount spider 60 or top mount spider 18, will now be transferred to the elevator 2, once the flush mount spider 60 or top mount spider 18 has been opened. The newly connected casing and casing string is then lowered into the well bore until the uppermost casing of the casing string reaches the rig floor. The flush mount spider 60 or top mount spider 18 is then set on the new uppermost casing, thereby taking over the load of the entire casing string. Once the flushmount spider 60 or top mount spider 18 is set, the elevator assembly 2 can be released, allowing the single joint elevator 200 to prepare to pick-up a new joint of casing.

In the foregoing specification, the inventions have been described with a specific embodiments thereof; however, it will be evident that various modifications and changes may be made thereto without departing from the broader spirit and scope of the invention.