CA1198411A - Drilling apparatus - Google Patents
Drilling apparatusInfo
- Publication number
- CA1198411A CA1198411A CA000434212A CA434212A CA1198411A CA 1198411 A CA1198411 A CA 1198411A CA 000434212 A CA000434212 A CA 000434212A CA 434212 A CA434212 A CA 434212A CA 1198411 A CA1198411 A CA 1198411A
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- Canada
- Prior art keywords
- tubular
- tong
- clamping
- transfer arm
- axis
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
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Abstract
IMPROVED DRILLING APPARATUS
ABSTRACT OF THE DISCLOSURE
A drill rig having a drill rig mast and a transfer arm is described. The clamps of the transfer arm are resiliently mounted to the transfer arm so as to provide limited axial movement of the clamps and thereby of a clamped downhole tubular. This resilient support for the downhole tubular serves to reduce damage to the threaded ends of the tubular during tubular handling operations. In addition, the clamps of the transfer arm are provided with resilient clamping surfaces which serve to engage the clamped tubular frictionally, without gouging or deeply scratching the surface thereof. A pair of automatic, self centering, hydraulic tongs is provided for making up and breaking out threaded connections of tubulars having various diameters without manual adjustment of the tongs. In an alternate embodiment, a swivel sub of variable effective length operates to provide similar advantages. Furthermore a novel mounting arrangement for tongs is described.
ABSTRACT OF THE DISCLOSURE
A drill rig having a drill rig mast and a transfer arm is described. The clamps of the transfer arm are resiliently mounted to the transfer arm so as to provide limited axial movement of the clamps and thereby of a clamped downhole tubular. This resilient support for the downhole tubular serves to reduce damage to the threaded ends of the tubular during tubular handling operations. In addition, the clamps of the transfer arm are provided with resilient clamping surfaces which serve to engage the clamped tubular frictionally, without gouging or deeply scratching the surface thereof. A pair of automatic, self centering, hydraulic tongs is provided for making up and breaking out threaded connections of tubulars having various diameters without manual adjustment of the tongs. In an alternate embodiment, a swivel sub of variable effective length operates to provide similar advantages. Furthermore a novel mounting arrangement for tongs is described.
Description
IMP VIED DRILLING APPARATUS
BACKGROUND OF THE INVENTION
The present invention relates to improvements in thread protecting devices for use in a drilling apparatus, and to improved toys for making up and breaking out threaded connections in a string of Donnelly tubular such as drill pipe, for example.
Drilling rigs with transfer arms and ho-draulically actuated tongs are known to the art. U.S.
Patent Rev 26,284, issued October 17, 1967 on an application of J. I. Only et at, is one early example of such a drilling rig. Such drilling rigs provide important advantages in terms of improved safety of operation, increased speed of operation, and reduced numbers of required operating personnel, as compared with conventional drilling rigs of the prior art. However, such drilling rigs have in the past suffered from certain disadvantages.
For example, one type of prior art transfer arm utilizes clamps for Donnelly tubular, which clamps are rigidly mounted to the transfer arm during use.
Y~1hen such transfer arms are used in connection with Jo drilling rigs having standard top head drives, the threaded ends of a clamped tubular can be damaged easily, as can the clamps and the transfer arm itself if the operator is not careful to control the axial forces applied to the clamped tubular with the top head drive during make up and break out operations. Further-more, this type of prior art transfer arm provides no adequate indication of the axial forces that are briny aped to the clamped tubular, thereby further increase ivy the prospect of damaged tubular, transfer arms and clamps.
In addition, it is customary to use rigid, serrated carbide inserts in transfer arm clamps, and these inserts can deeply gouge and scratch clamped tubular during handling operations. Such gouging can materially damage a clamped tubular, for transfer arm clamps customarily grip the relatively thin walled intermediate section of a clamped tubular, rather than the tool joints.
SUMMARY OF THE INVENTION
The present invention is directed to improved mounts for transfer arm clamps, improved transfer arm clamps, and improved tongs which alleviate these and other disadvantages of the prior art.
According to a first aspect of the present invention, an improvement to drilling apparatus is provided which operates to reduce thread wear and thread breakage at the threaded connection between a towhead drive unit and a Donnelly tubular threadedly engaged with the drive unit.
This improvement is provided for a drilling apparatus of a type which comprises a mast, a drive unit guided to travel along the mast, a transfer arm positioned adjacent the mast to move a only tubular between a lowered position near round level and a raised position aligned with the mast under the drive unit, and at least one clamp mounted on the transfer 5 arm to clamp the tubular TV the arm. This drilling apparatus is used with a Donnelly tubular itch defines an upper threaded end, and the drive unit comprises a threaded element adapted to mate with the upper threaded end of the tubular. In accordance with this 10 aspect of the invention, means are provided for resin-gently biasing one of the tubular and the threaded element against the other when the threaded element is brought into contact and mated with the tubular during make up operations, in order to permit axial movement 15 of said one of the tubular and the threaded element along the longitudinal axis of the tubular in the raised position, thereby reducing wear and damage to the upper threaded end of the tubular, as well as to the threaded element.
In a further embodiment, the invention contemplates a drilling apparatus which comprises a mast and a transfer arm positioned adjacent the mast to move down hole tubular between a lowered position near ground level and a raised position aligned with the mast. The improvement comprises at least one clamp adapted to grip a down hole tubular having at least one threaded end, and a means for mounting the clamp to the transfer arm such that the clamp is movable along an axis which is substantially parallel to the longitudinal axis of a tubular clamped in the at least one clamp. A
means resiliently biases the clamp to a rest position with respect to the transfer arm. The mounting means and biasing means cooperate to permit movement of the clamp under axial toads applied to a clamped down hole tubular during tubular handling operations, thereby reducing wear and damage to the threaded end of the clamped tubular.
Two distinct embodiments of this invention are disk cussed in detail below. In the firs-t, the transfer arm clamp is mounted to the transfer arm so as to move along an axis parallel to the longitudinal axis of -the clamped tubular. At least one sprint is mounted to bias the clamp to a rest position with respect to the arm, which rest position is situated such that -the -tubular is biased resiliently -toward -the -threaded element during wake up operations when the arm is in thy raised position In the second preferred embodiment of Figures 7 and I, the threaded element is mounted to the drive unit such -that it is the threaded element which is movable along an axis parallel to the direction of movement of the drive unit in the mast. This threaded element is, of course, rotatable by the drive unit. At least one spring is mounted to bias the -threaded element to a rest position with respect to the drive unit, which rest position is situated such that the threaded element is biased toward the tubular during make up operations when the arm is in the raised position.
This aspect of the invention provides two important ad van-taxes over the prior art approach of rigidly mounting the threaded element of the drive unit in place on the drive unit, and rigidly mounting the transfer arm clamps on the transfer arm. First, since one of the threaded element of the drive unit and the clamped tubular is mounted to move axially under applied loads, this movable element can move axially as necessary to reduce loads applied to the threaded end of the tubular during make up and break out operations. In addition, the position of the movable element (either the position of the clamped -tubular with respect to the transfer arm, or alternately the position of the biased threaded element with respect to the drive unit) provides an immediate, visual indication of the magnitude of the axial loads being applied to the clamped tubular. In this way, an operator is provided with the information needed to allow him to protect the clamped tubular from excessive axial loads. Both of these advantages cooperate to reduce the incidence of thread damage to a clamped tubular during handling operations.
According to a second feature of this invention, a drilling apparatus is provided with a pair of tongs positioned to make up and break out threaded lengths of Donnelly tubular from a string.
These tongs aye mounted on a platform which is positioned to translate along a guide toward and away from the axis of the string. Means are provided for rotating the second tong with respect to the first tong about the string axis in order selectively to tighten and loosen the threaded connection between the first and second lengths. In the preferred embodiment described below, the second or upper -tong rests on the first or luger tong, and the second tong is guided in its rotation on the first tong by an arcuate guide which is affixed to one of the first and second tongs, and an arcuate track which is affixed to the other of the first and second tongs. The track is positioned such that the guide interlocks with the track to limit movement of the second tong with respect to the first tong to rotation in the arc defined by the guide.
This mounting arrangement for two tongs has been found to be particularly effective. The manner of mounting the tongs on a platform which is guided for movement between a storage position and a clamping position allows the tongs to be stowed simply and easily when necessary, yet to be moved into an open-alive position when needed. Furthermore, the come bination of the arcuate guide and arcuate track used to mount the second tong to the first provides the nieces-spry guidance in a particularly simple and reliable manner.
According to a third feature of this invent lion, a drilling apparatus is provided with a pair of hydraulically actuated, self centering tongs positioned to make up and break out threaded lengths of down hole tubular from a string. Because these tongs are self-centering, they operate to center a tubular about a predetermined clamping axis for tubular ox widely varying diameters. These tongs can therefore be used for a wide range of tubular without manual adjustment In this way the need for manual adjustment is reduced or eliminated, and therefore the speed of operation of the tongs is increased.
S The self centering toys of this invention provide -the important advantage that in assembling a stripy of tubular such as drill pipe, the toys can be used to center an upper length of drill pipe prior to mutiny the upper length to a lower length, included in the string. In this way, even crooked tubular such as drill pipe may be assembled without ever requiring manual centering of the upper length. The toys of this invention provide an important safety advantage, in that operators can, to a large extent, stay away from moving lengths of -tubular, and can instead achieve the necessary control over the tubular by remote manipulation of the toys of this invention.
According to a fourth feature of this invent lion, a transfer arm clamp is provided with at least one resilient clamping surface. Preferably, this clamping surface is formed of a plastic material such as high density polyurethane in which there may be embedded a granular abrasive material such as sand or carbide to avoid axial slipping of clamped tubular.
the resilient clamping surfaces of this fourth feature of the invention serve to reduce the degree to which a clamped tubular is scratched or guyed by the transfer arm clamps, thereby reducing damage to and extending the operational life of clamped tubular.
As used herein, the term "Donnelly tubular"
denotes a length of a tube, rod or pipe of the type used in well drilling and finishing operations. This term is to be understood to include, without limit-anion, such items as drill pipe, drill killers, pro--diction tubing, sucker rods, and the like.
This invention, together with further objects and attendant advantages, will best be understood ho reference to the following detailed description taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
_ _ _ _ FIGURE 1 is a partial side elevation Al view showing a drilling rig which incorporates a first preferred embodiment of the invention described above, in which the transfer arm is shown in a lowered, substantially horizontal position.
FIGURE lo is a partial side elevation Al view of the structure of Figure 1 showing the transfer arm in a raised, substantially vertical position.
FIGURE pa is a sectional view taken along line aye of Figure 1.
FIGURE 2b is a sectional view taken along line 2b-2b of Figure 1.
FIGURE 2c is an enlarged side elevation Al view in partial cutaway of a portion of the drill rig of Figure 1.
FIGURE 3 it an enlarged view in partial cutaway of a portion of the transfer arm of Figure 1, with Fits. lo & 4= FIGURE 4 is an enlarged view in partial cutaway of a second preferred embodiment which cores-ponds to the structure of figure 3, appearing with Phase lo & 3.
FIGURE 5 is a sectional view taken along line 5-5 of Figure 1j appearing with Figs. 1 and 6.
FIGURE 6 is a sectional view taken along line 6-6 of Figure 1, appearing with jigs. 1 and 5.
FIGURE 7 is an elevation Al view of a drive unit coupled to a tubular by a second preferred embody-mint of the invention.
FIGURE 8 is a sectional view taken along line I of Figure 7.
DETAILED DESCRIPTION OF THE
PROSE TRY PREFERRED EMBODIMENTS
Referring now to the drawirlcJs, Err 1 shows a side elevation Al view of relevarlt portions of a mobile or portable drilling fly which embodies a first embodiment of the present invention describe briefly above.
FIRST PREFERRED EMBODIMENT
As shown in Figure 1, the drilling rig is mounted on a wheeled carrier or semi-trailer 10, and a mast 20 is mounted near the end of the carrier or semitrailer 10. Although shown here mounted on a wheeled carrier or semi-trailer, the drilling rig may be mounted on a portable substructure which may be either separate from or form a part of a carrier or semi-trailer. the mast 20 extends substantially vertically when it is set up for use, as shown in figures 1 and lay A transfer arm 30 is pivot ably mounted to the rear of the carrier 10 at a pivot 34. hydraulic cylinder 36 is provided to move the transfer arm 30 between a lowered, substantially horizontal position (as shown in Figure 1) and a raised, substantially vertical position (as shown in Figure lo). Means, such as slips 40, for supporting a string of Donnelly tubular are also mounted on the carrier 10. The slips 40 serve to transfer the weight of a string 42 of Donnelly tubular onto hydraulic jacks (not shown) via the carrier 10 or, alternatively, onto a substructure (also not shown) during certain phases of the tubular handling operation.
As best shown in Figure lay the illustrated drill rig also includes a power swivel 50 which is provided with a rotatable member 52. This power swivel 50 is arranged to move vertically within the mast 20, and it includes means for rotatlny the rotatable member 52. In this embodiment the power swivel 50 is used both to flit and to rotate individual lengths of Donnelly tubular, as well as the stripy 42 of Donnelly tubular.
I've portions of the drilling rich described above are structures which form the working environment for the present invention. These structures are familiar to those skilled in the art and accordingly will not be described in detail here.
Turning now to Figures pa, 2b, and 2c, the drilling rig of Figure 1 includes a pair of remotely controlled, self-centering, hydraulic wrenches (or "tongs" as they are called herein) 60,70. As best shown in Figure 2c, the lower hydraulic tong 70 is rigidly mounted to a base 72 which includes a Verdi-gaily oriented tube 74. As shown in Figure 2b, a pair of spaced, parallel guides 76 are rigidly mounted to the carrier 10. A support plate 78 is slid ably in-stalled within the guides 76 such that the support plate 78 is free to slide laterally along the length of the guides 76. A column 80 is rigidly mounted to the support plate 78 such that the column 80 fits within the tube 74.
A hydraulic cylinder 82 is positioned within the column 80 and is secured at one end to the support plate 78 and at the other end to the base 72. Thus, the base, and therefore the hydraulic tongs 60,70, are raised when the hydraulic cylinder 82 is extended. As will be explained in detail below, hydraulic cylinder 82 is used to control the height of the hydraulic tongs 60,70 during use. Locking screws 73 serve to lock the angular position of the tube 74 with respect to the column 80.
As best shown in Figure 2c, a second Howe draulic cylinder I is mounted between the carrier 10 and the lower end owe the column 80. This second hydraulic cylinder 84 is oriented substantially penal-lot to the bed of the carrier 10, and it operates to move the support plate 78 within the guides 76, thereby laterally displacing the hydraulic tongs 60,70. The second hydraulic cylinder 84 is used to move the hydraulic tongs 60,70 between a first position (as shown in Figure 2c) in which the tongs 60,70 are aligned over the axis of the string 42 of Donnelly tubular, and a retracted, second position (shown in dotted lines in Figure lay in which the tongs 60,70 are laterally displaced away from the axis of the string 42. In this way, the tongs 60,70 can readily be moved to a retracted position in which they do not impede or otherwise interfere with access to the string 42 of tubular.
As best shown in Egress pa and 2b, the upper hydraulic tong 60 is supported directly over the lower hydraulic tong 70 by means of two spaced archaic guides 90. Each of these guides 90 is mounted to the upper surface of the lower hydraulic tong 70. The upper hydraulic tong 60 is provided with two guide tracks 92 on its lower surface. Each of these guide tracks 92 is provided with an arcuate cut-out 94 which allows the respective guides 90 to contact the lower surface of the upper hydraulic tong 60 directly. The guide tracks 92 serve a guiding function in that they limit the movement of the upper hydraulic tong 60 with respect to I
the lower hydraulic tong 70 to rotation about the clamping axis. In this preferred embodiment, the upper hydraulic tong 60 is not secured to the guides 90, and i-t is merely the weight of the upper hydraulic tony 50 which holds the upper tony 60 in place with the yules 90 situated within the cut-outs 94 of the respective guide tracks 92. Preferably, grease fittings (no-t shown) are provided to introduce lubricants such as grease between the guides 90 and the respective guide tracks 92.
Upper and lower ever arms 96 are rigidly mounted to the upper hydraulic tong 60 by means of fasteners such as bolts 98. A third hydraulic cylinder 100 is mounted between the ends of the lever arms 96 and the base 72. As best shown in Figure pa, this third hydraulic cylinder 100 acts to rotate the upper hydraulic tong 60 with respect to the lower hydraulic tong 70~ The extent of rotation is indicated in Figure pa by the angle marked by the arrows 102. When the hydraulic cylinder 100 is extended the upper hydraulic tong 60 is rotated in a counterclockwise direction as seen from above; conversely, when the hydraulic cry-finder 100 is retracted the upper hydraulic tong 60 is rotated in a clockwise direction as seen from above.
Each of the hydraulic tongs 60,70 is preferably a self-centering clamp adapted to grip the tool joint of a respective length of Donnelly tubular.
Roth tongs 60,70 can comprise similar clamps. In this preferred embodiment, these clamps are self-centering without manual adjustment. That is, each clamp open-ales to grip a length ox Donnelly tubular about a fixed, predetermined clamping axis, regardless of the diameter of the clamped tubular. With the tongs 60,70 mounted as shown in Figure 1, this clamping axis is oriented vertically and passes through the point 104 of Figure pa.
The detailed structure of the clamps used in the tongs 60,70 will be described below in connection with Figure 6. Here it is enough to emphasize that because each of the tongs 60,70 operates to clamp a clamped tubular about a predetermined clamping axis, regardless of the diameter of the clamped tubular, no manual adjustment is needed to use the toys 60,70 with various diameters of Donnelly tubular. This is an important advantage, for it is routine to use a single set of hydraulic tongs 60,70 with Donnelly tubular having a wide range of diameters during a single well drilling and finishing operation. Because the need for manual adjustment of the tongs 60,70 is eliminated, the embodiment shown in the drawings operates more simply and quickly than hydraulic tongs of the prior art which do not provide automatic self centering as described above.
Turning now to the transfer arm shown in Figures 1 and lay a pair of clamps 120,122 are mounted to the transfer arm 30 by means of a support structure, which in this embodiment includes a shaft 130 which is slide ably mounted to the transfer arm 30 by means of two spaced guide structures 140,142. These guide structures 140,142 serve to maintain the shaft 130 in precise alignment with respect to the transfer arm 30 while allowing the shaft 130 limited axial movement.
The shaft 130 is provided with two spaced flanges 132,134, each of which is positioned near a respective one of the guide structures 140,142. Coil springs 150,152 are positioned concentrically about the shaft 130 so as to bear between the guide structures 140,142 and a respective one of the flanges 132,134. Each of the coil springs 150,152 resiliently resists the movement of the shaft 130 in a respective axial direct lion. Thus, the coil springs 150,152 act to bias the shaft 130 resiliently -to a rest position. Preferably, the coil springs 150,152 are proportioned so as to allow the shaft 130 to move approximately six inches to either side of this rest position. Preferably, the spring constant of these coil springs 150,152 is in the range of 1,000 to 2,000 pounds per inch of axial travel.
Figure 3 shows a detailed view in partial cutaway of a portion of the transfer arm 30 and the shaft 130, in which it can be clearly seen that the guide structure 140 includes a bushing 144 which acts to guide the axial movement of the shaft 130 with respect to the transfer arm 30. This bushing 144 also serves as a contact surface for the coil spring 150.
Preferably, the flange 132 is welded to the shaft 130 as shown in Figure 3.
figure 4 shows a portion of a second prefer-red embodiment of this invention, corresponding to the portion of Figure 3, which differs primarily in that a number of smaller coil springs 149' are substituted for the larger concentric coil spring 150. This second preferred embodiment includes the transfer arm 30, the guide structure 140, and the shaft 130 of the first preferred embodiment. However, this second preferred embodiment includes a somewhat modified flange 132' which is welded to the shaft 130. This modified flange 132' defines a plurality of openings 147' spaced around a circle centered on the shaft 130. Each of these openings 147' serves as a guide for a respective bolt 148', each of which is screwed into a respective threaded opening in a contact surface 146'. In each I
case, a coil spring 149' is mounted concentrically around the respective bolt 148' such that it bears at one end against the contact surface 146' and at the other end against the flange 132'. This second prefer red embodiment functions identically to the first, however, since none of the coil springs 149' is consign trig with the shaft 130, the coil springs 149' is concentric with the shaft 130, the coil springs 149' can readily be replaced as necessary without disassem-bring the shaft 130 from the guide structures 140,142.
Thus, the structure of Figure 4 is readily maintained and repaired in the field..
As previously mentioned, the clamps awry rigidly mounted to respective ends of the shaft 130. These two clamps are identical in structure, and will be described in detail in connection with Figure 6, which is a cross-sectional view of clamp 122.
Before describing the clamps 120,122 in detail, it should be noted that these clamps are, with certain exceptions to be explained in detail below, identical to the clamps described in co-pending apply-cation Serial No. 182,771, filed August 29, 1980, (now U.S. Patent No. 4,366,606) assigned to the assignee of the present invention. Reference can be made to that patent for its detailed description of -this clamp.
Turning now to Figure 6, clamp 122 includes two opposed clamping members 160,162 which are goner-ally rectangular in cross-section and are mounted to slide freely within a damping member guide structure which defines two mating rectangular cavities 170,172.
The clamping members 160,162 are precisely guided by the guide cavities 170,172 such that clamping members 160,162 are restricted to movement along a straight line. The guide cavities 170,172 are formed between two parallel side plates. Only one of these side plates 174 is shown in Figure 6; however, the second side plate (not shown) is parallel]. to and spaced from the side plate 174 such that the clamping members 160,162 move between the two side plates. Rocker arms 180,182 are mounted to the clamping members 160,162 about pivot points 184,186, respectively. Each of these rocker arms 180,182 is mounted to pivot about a respective pivot 188,1~0 supported by a cross-arm 192.
In addition, a hydraulic cylinder 194 is mounted between pivot points 196,198 on the ends of the rocker arms 180,182. Thus, as the hydraulic cylinder 194 varies the separation between the pivot points 196,198 on the rocker arms 180,182, the rocker arms 180,182 are caused to pivot about the pivot points 188,190, thereby causing the clamping members 160,162 to move along the straight line defined by the guide cavities 170,172.
A centering collar 200 is rotatable mounted on a pin 202 such that the centering collar 200 is free to rotate about an axis substantially parallel to the clamped tubular 230. A pair of link members 204,206 are mounted between the centering collar 200 and the rocker arms 180,182, respectively. As shown in Figure 6, the link members 204,206 are attached to the eon-toning collar 200 at two distinct attachment points 208,210, respectively. These attachment points 208,210 are selected such that, in the view shown in Figure 6, the centering collar 200 is caused to rotate in a clockwise manner when the clamping members 160,162 are moved toward one another, and in a counterclockwise manner when the clamping members 160,162 are moved away from one another.
~3~98~1 The attachment points 208,210 as well as the lengths of the link members 204,206 are chosen such that the centering collar 200 causes the two clamping members 160,162 to be symmetrically disposed with respect to the clamping axis 212. The clamping axis 212 can be thought of as a line passing through the axial center line of a clamped Donnelly tubular. In that the clamping members 160,162 are maintained in symmetrical positions with respect to the clamping axis 212, a clamped Donnelly tubular 230 is therefore consistently clamped in a predetermined position, regardless of the diameter of the clamped tubular 230.
The pin 202 is mounted in elongated slots (not shown) defined in the side plates 174. These elongated slots are oriented with their longest dime-soon pointing towards the clamping axis 212. These slots reserve to restrict the movement of the pin 202 in a direction parallel to the direction of movement of the clamping members 160,162 while allowing limited travel of the pin 202 towards and away from the clamp-in axis 212. This limited movement is provided to accommodate the slight change in separation between the cross-arm 192 and the clamping members 160,162 as the rocker arms 180,1~2 assume varying angular positions.
As shown in Figure 6, each of the clamping members 160,162 includes a respective clamping surface 220,222. In this embodiment, each of the clamping surfaces 220,222 is formed of a wear-resistant plastic material such as a high density polyurethane. Prefer-ably, a granular abrasive, such as sand or carbide for example, is embedded in the plastic material to improve the gripping characteristics of the clamping surfaces.
The clamping surfaces are mounted to the clamping members 160,162 by means of fasteners 224.
Because the clamping surfaces 220,222 are formed of a resilient plastic material, they are adapted to engage and grip the clamped tubular 230 frictionally without guying the surface of the tubular 230 and without leaving deep clamping marks on the tubular 230. As shown in Figure 1, the clamps 120,122 are used to grip the clamped tuber 230 at inte~med~
tale positions between the tool joints 232,234. Such intermediate portions generally have thinner walls which are more easily damaged by clamps than are the tool joints 232,234. The clamps 120,122 minimize gouging and other damage to the clamped tubular 230 by providing resilient clamping surfaces 220,222 which are adapted to engage the clamped tubular 230 frictionally without leaving deep scratches or gouges. Scratching or gouging can be a significant problem with transfer arms of the prior art, foe tubular are often not precisely straight. Also, the clamped tubular 230 is subjected to large accelerations as the transfer arm 30 is moved from the lowered position shown in Figure 1 to the raised position shown in Figure lay These con-dictions can cause ordinary clamps of the type having rigid, serrated clamping surfaces to leave undesirable scratches or gouges in the intermediate portions of -the clamped tubular 230.
Referring now to Figure 5, means are provided for rotating the shaft 130 and thereby the clamps 120,122 with respect to the transfer arm 30. This rotating means includes a plate 250 which is provided with an arc-shaped cutout 252 as well as four key ways 254. The upper portion of the shaft 130 is provided with four mating keys 256 which are positioned to slide within the key ways 254 in the plate 250. The keys 256 and the key ways 254 cooperate to allow the shaft 130 I
to slide axially within the plate 250 while trays-mutating torque from the plate 250 to the shaft 130.
The plate 250 is held in place against the guide structure 1~2 by means of a pin 258 which is positioned inside the arc-shaped cutout 252 in the plate 250.
Preferably, means (not shown) are provided for adjust-in the position of the pin 258 in order to adjust the stop positions of the plate 250.
A hydraulic cylinder is positioned between an attachment point 262 in the plate 250 and the extreme end section of the transfer arm 30. This hydraulic cylinder 266 acts to rotate the plate 250 and thereby the shaft 130 through a 90 arc. The pin 252 acts as a stop which defines the two extreme rotational positions of the plate 250 and thrower the shaft 130. Figure 5 shows the pin 258 in a first position and the hydraulic cylinder 266 attached to the first attachment point 262. When so configured, the hydraulic cylinder 266 acts to rotate the plate 250 in a counterclockwise direction through an arc of 90. By merely moving the pin 258 from the position shown in Figure 6 to the alternate position 260 and then removing the hydraulic cylinder 266 from the first attachment point 262 to the second attachment point 26~, the hydraulic cylinder 266 can be made to rotate the plate 250 in a clockwise direction through an angular arc of 90.
The hydraulic cylinder 266 is used to rotate the shaft 130 and therefore the clamps 120,122 to facilitate the loading and unloading of tubular to and from the clamps 120,122. When the clamps 120,122 are rotated such that the line between the pin 202 and the clamping axis 212 is substantially horizontal, the clamps 120,122 are facing to the side, and tubular can readily be rolled into or out of the clamps 120,122.
By means of the alternate attachment points 262,264, the cylinder 266 can readily be configured to rotate the clamps 120,122 to whichever side of the transfer arm is more convenient. Conversely, when the hydraulic 5 cylinder 266 is used to rotate the clamps 120,122 to the position shown in Figures l and lay the clamped tubular 230 is positioned in line with the axis of the string 42 when the trarlsfer arm 30 is in the raised position shown in Figure lay lo The hydraulic tongs 60,70 are each self-centering clamps substantially identical in structl1re to the clamp of Figure 6. The single difference between the tongs 60,70 and the clamp of Figure 6 is that each of the tongs 60,70 is provided with a con-ventional, rigid, hard clamping surface instead of the resilient clamping surfaces 220,222 shown in Figure 6.
These rigid clamping surfaces, which bear only on the tool joints of the respective tubular, are adapted to provide a firm grip which substantially prevents a clamped tubular from rotating in the tongs 60,70.
It should be understood that the present invention is not limited to the particular type of self-centering clamp shown in Figure 6. To the con-tray, other types of self-centering clamps, such as those shown in described in co-pending patent apply-cations Serial No. 074,547, filed September if, 1979, (now U.S. Patent No. 4,303,270), assigned -to the assignee of the present invention, provide a self-centering action by means of other structures.
Having described the structure Ox the pro-furred embodiments of the drawings, the operation of this structure can now be described by tracing the steps needed to add and remove a length of Donnelly -- 19 _ tubular to a string. The first step in adding a length is to position the transfer arm 30 in the lower, substantially horizontal position shown in Figure 1 and to rotate the clamps 120,122 to the side positiorm A
length of Donnelly tubular 230 is then placed in the clamps 120,122 and the clamps are closed to grip the clamped tubular 230 securely. This clamped tubular 230 defines tool joints 232,234 at opposite ends thereof, and the lower tool joint 232 includes a threaded end 236. The transfer arm 30 is then pivoted about the pivot 34 to the raised, substantially vertical position shown in figure lay At this point, the hydraulic cylinder 266 is used to rotate the clamps 120,122 to the position shown in figure lay In this rotated position the clamped tubular 230 is aligned with the axis of the string 42.
Once the clamped tubular 230 is in the rotated position, the power swivel 50 is then lowered onto the upper tool joint 234 of the clamped tubular 230. As the power swivel 50 is lowered, the rotatable member 52 of the power swivel 50 is rotated to engage the threads of the rotatable member 52 with the threads of the upper tool joint 234. During this operation, the coil spring 150 acts to support the clamped tubular 230 resiliently such that the clamped tubular 230 is free to move downward under the axial forces applied to the tubular 230 by the power swivel 50. In this way, strain on the threads of the upper tool joint 234 it maintained at an acceptable level while the threaded connection is being made up.
In addition, the degree of compression of the spring 150 as well as the axial position of the clamped tubular 230 provide a visual indication to the operator of the drill rig as to the magnitude of the axial forces which are being applied by the power swivel 50 to the clamped tubular 230. This visual indication assists the operator in controlling the pudgier swivel 50 so as not to exert undue axial forces on -the clumped tubular 230. Because the clamped tubular 230 is free to move axially under applied forces, the precise pOSitiOIl of the power swivel 50 is less critical.
The combination of axial movement of the clamped tubular 230 as well as resilient biasing of the position of the clamped tubular 230 provides important protection to the clamped tubular, thereby making tubular handling operations less sensitive to operator error and consequently reducing operator damage to clamped tubular. In addition, the resilient clamping surfaces 220,222 of the clamps 120,122 reduce the incidence of clamping marks on the intermediate section of the clamped tubular 230 and thereby increase the useful working life of these tubular.
Once the upper tool joint 234 has been mated with the power swivel 50, the clamps 120,122 are opened and the transfer arm 30 is lowered, leaving the tubular 230 suspended from the power swivel 50. The power swivel 50 is then lowered to bring the tubular 230 into contact with the uppermost length of tubular included in the string 42. The tongs 60,70 are positioned by means of the cylinder 82 such that the upper tong 60 is positioned adjacent the lower tool joint 232 of the tubular 230, and the lower tong 70 is positioned adjacent the uppermost tool joint of the string 42.
The upper tong 60 can be closed partially about the tubular 230 to center the lower end of the tubular 230 about the clamping axis, so as properly to align the tubular 230 for mating with the string 42. The rotate able member 52 of the power swivel 50 is then rotated so as to engage the threaded end 236 of the tubular 230 with the uppermost portion of the string 42. The power swivel 50 is, however, not used to complete the mutiny of the tubular 230 with the string 42.
Rather, the tongs 60,70 are closed and then the hydraulic cylinder 100 is used to rotate the upper tong 60 so as to tighten the threaded connection between the tubular 230 and the string 42. Standard pressure regulators are preferably used to control the hydraulic pressure used to drive the hydraulic cylinder 100, and thereby precisely to control the make up torque. Once the tubular 230 is secured to the string 42, the slips 40 and the tongs 60,70 are loosened; the power swivel 50 is then used to support and rotate the tubular 230, which is now an integral part of the string 42.
When a length of Donnelly tubular is to be removed from a drill string, the above-described operations are substantially reversed. First, the power swivel 50 is used to raise the string 42 such that the uppermost tubular is raised above the carrier 10. The slips 40 are then used to support the weight of the drill string 42, and the tongs 60,70 are post-toned such that the upper tong 60 bears on the lower tool joint of the uppermost tubular of the string 42.
The tongs 60,~0 are then used to break the threaded connection between the uppermost tubular and the string, and then the swivel 50 is used to rotate the uppermost tubular and thereby to separate it from the string.
The transfer arm 30 is positioned to the vertical position and the clamps 120,122 are clamped on the uppermost tubular suspended from the swivel 50. The swivel is then rotated to break the threaded connection between the uppermost tubular and the swivel 50.
I
During this operation the upper sprint 152 resists the upward movement of the clamped tubular under the axial load applied by the swivel 50. As before, the coil spring 152 acts to allow limited axial motion and to provide a visual indication of the axial loads briny applied to the clamped Tyler In this joy, excessive forces on the threads of the upper tool joint 234 are reduced during tubular handling operations. Once the clamped tuber has been separated from the swivel 50, the transfer arm 30 is then towered to bring the clamped tubular to the position shown in Figure 1.
The tongs 60,70 provide a number of important advantages. Because each of the toys 60,70 utilizes a self-centering clamp such as the one shown in Figure 6, manual adjustment of the tongs is not required when varying size tubular are used. The combination of the transfer arm 30 and the tongs 60,70 results in a highly automated drill rig which to a great extent eliminates the need for operators to remain in dangerous positions near the moving tubular as it is installed in and removed from the drill string. This is an important safety consideration which also reduces the number of personnel required to operate the drill rig, and thereby the drooling costs.
From the foregoing, it should be apparent that an improved drill rig has been described which markedly reduces clamp damage and thread damage to clamped tubular during tubular handling operations.
In addition, this invention provides self-centering tongs which supply the torque necessary for reproduce-able and effective maze up and break out of threaded connections in a drill string, and which can be used to center and properly align lengths of tubular. Of course, it should be understood that the novel tong mounting system described above can be used with toys which do not provide a self centering function.
THE SECOND PREFERRED EMBODIMENT
Turning now to Egress 7 and 8, a second preferred embodiment of this invention will now be described.
As shown in Figure 7, this second preferred embodiment includes a swivel sub 350, which its threadedly engaged with a threaded tube 342 included in a power swivel 340. The swivel sub 350 of this invention is adapted to be threadedly connected with the upper end 332 of a clamped Donnelly tubular 330.
my way of general background, the power swivel 340 is mounted to move vertically within a drill rig mast 300. The tubular 330 is clamped in a transfer arm 310 by means of two clamps 320, the upper of which is shown in Figure 7. Figure 7 shows only portions of the drilling apparatus and the transfer arm 310, and the remaining portions which are not illustrated in Figure 7 are identical to the first preferred embodiment shown and described above. In use, the power swivel 340 operates to rotate the swivel sub 350 and thereby the tubular 330 during drilling operations.
In order to engage the tubular 330 with the power swivel 340, the power swivel 340 is used to rotate the swivel sup 350 as the swivel sub 350 is lowered onto the clamped tubular 330. In this way, the lower end of the swivel sub 350 threadedly engages the upper end 332 of the tubular 330. After this has been accomplished, the tubular 330 is then released from the clamps 320, and drilling operations continue.
The clamp 320 differs from the transfer arm clamps discussed above in that the clamp 320 is mounted Lo to the transfer arm 310 at a fixed axial position, and is not free to move longitudinally along the longitude final axis of the tubular 330.
As explained above, damage and breakage to the threads of the upper end 332 of the tubular 330 can result if the entire demurred force supplied by the power swivel 340 is brought to bear on the upper end 332 of the tubular 330 before the threaded connection is fully made up. This second preferred embodiment of the invention avoids this problem by providing an improved swivel sub 350 which includes means for resiliently allowing the effective length of the swivel sub 350 to vary within predetermined limits in order to reduce the axial forces applied to partially made up threaded joints.
Figure 8 shows a cross-sectional view of the swivel sub 350 which is made up of two major coupon-ens: an upper sleeve 360 and a lower sleeve 380. The upper sleeve 360 includes an upper collar 362 which defines an array of internal upper threads 368 adapted to threadedly engage the threaded tube 342 of the power swivel 340. The upper sleeve 360 also defines an array of internal splints 364, oriented to extend longitude finally along the length of the upper sleeve 360. An internal shoulder 366 is defined at the lower end of the internal splints 364. The upper sleeve 360 defines a lower stop surface 370 at its lowermost outer sun-face.
The lower sleeve 330 includes a lower collar 382 which is threadedly held in place at the lower end of the lower sleeve 380. This lower collar 382 defines an array of lower external threads 384 sized and shaped to threadedly engage the upper end 332 of the tubular 330. This lower collar 382 defines an upper annular extension 386 positioned around the lower sleeve 380 so as to define an annular recess 388 there between. The uppermost surface of this annular extension 386 defines a stop surface 390 which is aligned to abut the upper stop surface 370 of the upper sleeve 360.
The lower sleeve 380 defines an array of external splints 392 sized to mate with the internal splints 364. In addition, the lower sleeve 380 defines an external shoulder 394 positioned to abut the inter-net shoulder 366 of the upper sleeve 360 when the lower sleeve 380 is in a fully extended position with respect to the upper sleeve 360. A packing collar 396 is threadedly connected to the upper end of the lower sleeve 380, and the packing collar 396 defines a recess which receives an annular packing element 398. A
packing retaining ring 400 is threadedly engaged on the upper end of the lower sleeve 380 to confine the packing element 398 in place.
A coil spring 410 is positioned around the lower sleeve 380 between the lower collar 382 and the upper sleeve 360. This coil spring 410 operates to bias the lower sleeve 380 away from the upper sleeve 360 into the extended or extracted position shown in Figure 8. When compressive axial forces are applied tending to push the lower sleeve 380 into the upper sleeve 360, the spring 410 resiliently resists such retraction. However, sufficient compressive forces will cause the lower sleeve 380 to telescope within the upper sleeve 360. Thus, the splints 364,392 operate to transmit rotary motion from the upper sleeve 360 to the lower sleeve 380, while allowing the lower sleeve 380 to move axially within the upper sleeve 360. The upper and lower stop surfaces 370,390 define the maximum extent to which the lower sleeve 380 can telescope within the upper so eve Preferably, the upper and lower collars 362,382 are held in place on the resees-live sleeves 360,380 by means of a locking agent such as LACTATE in order to insure that break out does not occur.
In the preferred embodiment of Figures 7 anal 8, the lower threads 384 on the lower collar 382 are 4-1/2 inch APT IF threads. For this embodiment, the swivel sub 350 is stressed for about 500,000 pounds.
The spring 410 in this preferred embodiment provides a spring constant in the range of about 100-400 pounds per inch. The biasing force developed by the spring 410 urges the lower threads 384 of the lower collar 382 into engagement with the upper end 332 of the tubular lo 330, while allowing the lower collar 382 to be pushed upwardly as necessary to avoid thread damage to the upper end 332 of the tubular 330. In this preferred embodiment, the maximum travel of the lower sleeve 380 with respect to the upper sleeve 360 between the extended position shown in Figure 8 and the retracted position, in which the stop surfaces 370,390 are in contact, is about one and one-half times the axial make up travel when the lower threads 384 are engaged on the upper end 332 of the tubular 330. Of course, for threads larger than the awl/ inch PUFF thread described above, it may well be preferable to use a spring with a higher spring constant than that described above, and conversely, smaller spring con-slants may be suitable for smaller threads.
From the foregoing, it should be apparent that an improved swivel sub 350 has been described which acts to provide a resilient biasing force during make up operations with a clamped tubular 330. This resilient biasing force can reduce thread loading *trade mark 34~
during make up operations, and thereby reduce thread damage. Furthermore, the swivel sub 350 gives an open-atop a positive measure of the forces briny applied on threads during make up operations. In particular, the S operator can visually yaucJe the separation button the two stop surfaces 370,390 in order to determine the magnitude of forces being applied to the upper end 332 of the tubular 330. The vertical position of the power swivel 340 in the drill fly mast 300 can then be adjusted to maintain this downward force on the upper end 332 within the desired range. In this way, the need for extremely precise control of the vertical position of the power swivel 340 is largely avoided.
Of course, it should be understood that the embodiments illustrated in the drawings and discussed above are illustrative examples set forth to describe preferred embodiments of the invention in detail.
Various changes and modifications to the preferred embodiments described above can be made without depart-in from the spirit and scope of the present invention which is defined by the following claims, including all equivalents.
BACKGROUND OF THE INVENTION
The present invention relates to improvements in thread protecting devices for use in a drilling apparatus, and to improved toys for making up and breaking out threaded connections in a string of Donnelly tubular such as drill pipe, for example.
Drilling rigs with transfer arms and ho-draulically actuated tongs are known to the art. U.S.
Patent Rev 26,284, issued October 17, 1967 on an application of J. I. Only et at, is one early example of such a drilling rig. Such drilling rigs provide important advantages in terms of improved safety of operation, increased speed of operation, and reduced numbers of required operating personnel, as compared with conventional drilling rigs of the prior art. However, such drilling rigs have in the past suffered from certain disadvantages.
For example, one type of prior art transfer arm utilizes clamps for Donnelly tubular, which clamps are rigidly mounted to the transfer arm during use.
Y~1hen such transfer arms are used in connection with Jo drilling rigs having standard top head drives, the threaded ends of a clamped tubular can be damaged easily, as can the clamps and the transfer arm itself if the operator is not careful to control the axial forces applied to the clamped tubular with the top head drive during make up and break out operations. Further-more, this type of prior art transfer arm provides no adequate indication of the axial forces that are briny aped to the clamped tubular, thereby further increase ivy the prospect of damaged tubular, transfer arms and clamps.
In addition, it is customary to use rigid, serrated carbide inserts in transfer arm clamps, and these inserts can deeply gouge and scratch clamped tubular during handling operations. Such gouging can materially damage a clamped tubular, for transfer arm clamps customarily grip the relatively thin walled intermediate section of a clamped tubular, rather than the tool joints.
SUMMARY OF THE INVENTION
The present invention is directed to improved mounts for transfer arm clamps, improved transfer arm clamps, and improved tongs which alleviate these and other disadvantages of the prior art.
According to a first aspect of the present invention, an improvement to drilling apparatus is provided which operates to reduce thread wear and thread breakage at the threaded connection between a towhead drive unit and a Donnelly tubular threadedly engaged with the drive unit.
This improvement is provided for a drilling apparatus of a type which comprises a mast, a drive unit guided to travel along the mast, a transfer arm positioned adjacent the mast to move a only tubular between a lowered position near round level and a raised position aligned with the mast under the drive unit, and at least one clamp mounted on the transfer 5 arm to clamp the tubular TV the arm. This drilling apparatus is used with a Donnelly tubular itch defines an upper threaded end, and the drive unit comprises a threaded element adapted to mate with the upper threaded end of the tubular. In accordance with this 10 aspect of the invention, means are provided for resin-gently biasing one of the tubular and the threaded element against the other when the threaded element is brought into contact and mated with the tubular during make up operations, in order to permit axial movement 15 of said one of the tubular and the threaded element along the longitudinal axis of the tubular in the raised position, thereby reducing wear and damage to the upper threaded end of the tubular, as well as to the threaded element.
In a further embodiment, the invention contemplates a drilling apparatus which comprises a mast and a transfer arm positioned adjacent the mast to move down hole tubular between a lowered position near ground level and a raised position aligned with the mast. The improvement comprises at least one clamp adapted to grip a down hole tubular having at least one threaded end, and a means for mounting the clamp to the transfer arm such that the clamp is movable along an axis which is substantially parallel to the longitudinal axis of a tubular clamped in the at least one clamp. A
means resiliently biases the clamp to a rest position with respect to the transfer arm. The mounting means and biasing means cooperate to permit movement of the clamp under axial toads applied to a clamped down hole tubular during tubular handling operations, thereby reducing wear and damage to the threaded end of the clamped tubular.
Two distinct embodiments of this invention are disk cussed in detail below. In the firs-t, the transfer arm clamp is mounted to the transfer arm so as to move along an axis parallel to the longitudinal axis of -the clamped tubular. At least one sprint is mounted to bias the clamp to a rest position with respect to the arm, which rest position is situated such that -the -tubular is biased resiliently -toward -the -threaded element during wake up operations when the arm is in thy raised position In the second preferred embodiment of Figures 7 and I, the threaded element is mounted to the drive unit such -that it is the threaded element which is movable along an axis parallel to the direction of movement of the drive unit in the mast. This threaded element is, of course, rotatable by the drive unit. At least one spring is mounted to bias the -threaded element to a rest position with respect to the drive unit, which rest position is situated such that the threaded element is biased toward the tubular during make up operations when the arm is in the raised position.
This aspect of the invention provides two important ad van-taxes over the prior art approach of rigidly mounting the threaded element of the drive unit in place on the drive unit, and rigidly mounting the transfer arm clamps on the transfer arm. First, since one of the threaded element of the drive unit and the clamped tubular is mounted to move axially under applied loads, this movable element can move axially as necessary to reduce loads applied to the threaded end of the tubular during make up and break out operations. In addition, the position of the movable element (either the position of the clamped -tubular with respect to the transfer arm, or alternately the position of the biased threaded element with respect to the drive unit) provides an immediate, visual indication of the magnitude of the axial loads being applied to the clamped tubular. In this way, an operator is provided with the information needed to allow him to protect the clamped tubular from excessive axial loads. Both of these advantages cooperate to reduce the incidence of thread damage to a clamped tubular during handling operations.
According to a second feature of this invention, a drilling apparatus is provided with a pair of tongs positioned to make up and break out threaded lengths of Donnelly tubular from a string.
These tongs aye mounted on a platform which is positioned to translate along a guide toward and away from the axis of the string. Means are provided for rotating the second tong with respect to the first tong about the string axis in order selectively to tighten and loosen the threaded connection between the first and second lengths. In the preferred embodiment described below, the second or upper -tong rests on the first or luger tong, and the second tong is guided in its rotation on the first tong by an arcuate guide which is affixed to one of the first and second tongs, and an arcuate track which is affixed to the other of the first and second tongs. The track is positioned such that the guide interlocks with the track to limit movement of the second tong with respect to the first tong to rotation in the arc defined by the guide.
This mounting arrangement for two tongs has been found to be particularly effective. The manner of mounting the tongs on a platform which is guided for movement between a storage position and a clamping position allows the tongs to be stowed simply and easily when necessary, yet to be moved into an open-alive position when needed. Furthermore, the come bination of the arcuate guide and arcuate track used to mount the second tong to the first provides the nieces-spry guidance in a particularly simple and reliable manner.
According to a third feature of this invent lion, a drilling apparatus is provided with a pair of hydraulically actuated, self centering tongs positioned to make up and break out threaded lengths of down hole tubular from a string. Because these tongs are self-centering, they operate to center a tubular about a predetermined clamping axis for tubular ox widely varying diameters. These tongs can therefore be used for a wide range of tubular without manual adjustment In this way the need for manual adjustment is reduced or eliminated, and therefore the speed of operation of the tongs is increased.
S The self centering toys of this invention provide -the important advantage that in assembling a stripy of tubular such as drill pipe, the toys can be used to center an upper length of drill pipe prior to mutiny the upper length to a lower length, included in the string. In this way, even crooked tubular such as drill pipe may be assembled without ever requiring manual centering of the upper length. The toys of this invention provide an important safety advantage, in that operators can, to a large extent, stay away from moving lengths of -tubular, and can instead achieve the necessary control over the tubular by remote manipulation of the toys of this invention.
According to a fourth feature of this invent lion, a transfer arm clamp is provided with at least one resilient clamping surface. Preferably, this clamping surface is formed of a plastic material such as high density polyurethane in which there may be embedded a granular abrasive material such as sand or carbide to avoid axial slipping of clamped tubular.
the resilient clamping surfaces of this fourth feature of the invention serve to reduce the degree to which a clamped tubular is scratched or guyed by the transfer arm clamps, thereby reducing damage to and extending the operational life of clamped tubular.
As used herein, the term "Donnelly tubular"
denotes a length of a tube, rod or pipe of the type used in well drilling and finishing operations. This term is to be understood to include, without limit-anion, such items as drill pipe, drill killers, pro--diction tubing, sucker rods, and the like.
This invention, together with further objects and attendant advantages, will best be understood ho reference to the following detailed description taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
_ _ _ _ FIGURE 1 is a partial side elevation Al view showing a drilling rig which incorporates a first preferred embodiment of the invention described above, in which the transfer arm is shown in a lowered, substantially horizontal position.
FIGURE lo is a partial side elevation Al view of the structure of Figure 1 showing the transfer arm in a raised, substantially vertical position.
FIGURE pa is a sectional view taken along line aye of Figure 1.
FIGURE 2b is a sectional view taken along line 2b-2b of Figure 1.
FIGURE 2c is an enlarged side elevation Al view in partial cutaway of a portion of the drill rig of Figure 1.
FIGURE 3 it an enlarged view in partial cutaway of a portion of the transfer arm of Figure 1, with Fits. lo & 4= FIGURE 4 is an enlarged view in partial cutaway of a second preferred embodiment which cores-ponds to the structure of figure 3, appearing with Phase lo & 3.
FIGURE 5 is a sectional view taken along line 5-5 of Figure 1j appearing with Figs. 1 and 6.
FIGURE 6 is a sectional view taken along line 6-6 of Figure 1, appearing with jigs. 1 and 5.
FIGURE 7 is an elevation Al view of a drive unit coupled to a tubular by a second preferred embody-mint of the invention.
FIGURE 8 is a sectional view taken along line I of Figure 7.
DETAILED DESCRIPTION OF THE
PROSE TRY PREFERRED EMBODIMENTS
Referring now to the drawirlcJs, Err 1 shows a side elevation Al view of relevarlt portions of a mobile or portable drilling fly which embodies a first embodiment of the present invention describe briefly above.
FIRST PREFERRED EMBODIMENT
As shown in Figure 1, the drilling rig is mounted on a wheeled carrier or semi-trailer 10, and a mast 20 is mounted near the end of the carrier or semitrailer 10. Although shown here mounted on a wheeled carrier or semi-trailer, the drilling rig may be mounted on a portable substructure which may be either separate from or form a part of a carrier or semi-trailer. the mast 20 extends substantially vertically when it is set up for use, as shown in figures 1 and lay A transfer arm 30 is pivot ably mounted to the rear of the carrier 10 at a pivot 34. hydraulic cylinder 36 is provided to move the transfer arm 30 between a lowered, substantially horizontal position (as shown in Figure 1) and a raised, substantially vertical position (as shown in Figure lo). Means, such as slips 40, for supporting a string of Donnelly tubular are also mounted on the carrier 10. The slips 40 serve to transfer the weight of a string 42 of Donnelly tubular onto hydraulic jacks (not shown) via the carrier 10 or, alternatively, onto a substructure (also not shown) during certain phases of the tubular handling operation.
As best shown in Figure lay the illustrated drill rig also includes a power swivel 50 which is provided with a rotatable member 52. This power swivel 50 is arranged to move vertically within the mast 20, and it includes means for rotatlny the rotatable member 52. In this embodiment the power swivel 50 is used both to flit and to rotate individual lengths of Donnelly tubular, as well as the stripy 42 of Donnelly tubular.
I've portions of the drilling rich described above are structures which form the working environment for the present invention. These structures are familiar to those skilled in the art and accordingly will not be described in detail here.
Turning now to Figures pa, 2b, and 2c, the drilling rig of Figure 1 includes a pair of remotely controlled, self-centering, hydraulic wrenches (or "tongs" as they are called herein) 60,70. As best shown in Figure 2c, the lower hydraulic tong 70 is rigidly mounted to a base 72 which includes a Verdi-gaily oriented tube 74. As shown in Figure 2b, a pair of spaced, parallel guides 76 are rigidly mounted to the carrier 10. A support plate 78 is slid ably in-stalled within the guides 76 such that the support plate 78 is free to slide laterally along the length of the guides 76. A column 80 is rigidly mounted to the support plate 78 such that the column 80 fits within the tube 74.
A hydraulic cylinder 82 is positioned within the column 80 and is secured at one end to the support plate 78 and at the other end to the base 72. Thus, the base, and therefore the hydraulic tongs 60,70, are raised when the hydraulic cylinder 82 is extended. As will be explained in detail below, hydraulic cylinder 82 is used to control the height of the hydraulic tongs 60,70 during use. Locking screws 73 serve to lock the angular position of the tube 74 with respect to the column 80.
As best shown in Figure 2c, a second Howe draulic cylinder I is mounted between the carrier 10 and the lower end owe the column 80. This second hydraulic cylinder 84 is oriented substantially penal-lot to the bed of the carrier 10, and it operates to move the support plate 78 within the guides 76, thereby laterally displacing the hydraulic tongs 60,70. The second hydraulic cylinder 84 is used to move the hydraulic tongs 60,70 between a first position (as shown in Figure 2c) in which the tongs 60,70 are aligned over the axis of the string 42 of Donnelly tubular, and a retracted, second position (shown in dotted lines in Figure lay in which the tongs 60,70 are laterally displaced away from the axis of the string 42. In this way, the tongs 60,70 can readily be moved to a retracted position in which they do not impede or otherwise interfere with access to the string 42 of tubular.
As best shown in Egress pa and 2b, the upper hydraulic tong 60 is supported directly over the lower hydraulic tong 70 by means of two spaced archaic guides 90. Each of these guides 90 is mounted to the upper surface of the lower hydraulic tong 70. The upper hydraulic tong 60 is provided with two guide tracks 92 on its lower surface. Each of these guide tracks 92 is provided with an arcuate cut-out 94 which allows the respective guides 90 to contact the lower surface of the upper hydraulic tong 60 directly. The guide tracks 92 serve a guiding function in that they limit the movement of the upper hydraulic tong 60 with respect to I
the lower hydraulic tong 70 to rotation about the clamping axis. In this preferred embodiment, the upper hydraulic tong 60 is not secured to the guides 90, and i-t is merely the weight of the upper hydraulic tony 50 which holds the upper tony 60 in place with the yules 90 situated within the cut-outs 94 of the respective guide tracks 92. Preferably, grease fittings (no-t shown) are provided to introduce lubricants such as grease between the guides 90 and the respective guide tracks 92.
Upper and lower ever arms 96 are rigidly mounted to the upper hydraulic tong 60 by means of fasteners such as bolts 98. A third hydraulic cylinder 100 is mounted between the ends of the lever arms 96 and the base 72. As best shown in Figure pa, this third hydraulic cylinder 100 acts to rotate the upper hydraulic tong 60 with respect to the lower hydraulic tong 70~ The extent of rotation is indicated in Figure pa by the angle marked by the arrows 102. When the hydraulic cylinder 100 is extended the upper hydraulic tong 60 is rotated in a counterclockwise direction as seen from above; conversely, when the hydraulic cry-finder 100 is retracted the upper hydraulic tong 60 is rotated in a clockwise direction as seen from above.
Each of the hydraulic tongs 60,70 is preferably a self-centering clamp adapted to grip the tool joint of a respective length of Donnelly tubular.
Roth tongs 60,70 can comprise similar clamps. In this preferred embodiment, these clamps are self-centering without manual adjustment. That is, each clamp open-ales to grip a length ox Donnelly tubular about a fixed, predetermined clamping axis, regardless of the diameter of the clamped tubular. With the tongs 60,70 mounted as shown in Figure 1, this clamping axis is oriented vertically and passes through the point 104 of Figure pa.
The detailed structure of the clamps used in the tongs 60,70 will be described below in connection with Figure 6. Here it is enough to emphasize that because each of the tongs 60,70 operates to clamp a clamped tubular about a predetermined clamping axis, regardless of the diameter of the clamped tubular, no manual adjustment is needed to use the toys 60,70 with various diameters of Donnelly tubular. This is an important advantage, for it is routine to use a single set of hydraulic tongs 60,70 with Donnelly tubular having a wide range of diameters during a single well drilling and finishing operation. Because the need for manual adjustment of the tongs 60,70 is eliminated, the embodiment shown in the drawings operates more simply and quickly than hydraulic tongs of the prior art which do not provide automatic self centering as described above.
Turning now to the transfer arm shown in Figures 1 and lay a pair of clamps 120,122 are mounted to the transfer arm 30 by means of a support structure, which in this embodiment includes a shaft 130 which is slide ably mounted to the transfer arm 30 by means of two spaced guide structures 140,142. These guide structures 140,142 serve to maintain the shaft 130 in precise alignment with respect to the transfer arm 30 while allowing the shaft 130 limited axial movement.
The shaft 130 is provided with two spaced flanges 132,134, each of which is positioned near a respective one of the guide structures 140,142. Coil springs 150,152 are positioned concentrically about the shaft 130 so as to bear between the guide structures 140,142 and a respective one of the flanges 132,134. Each of the coil springs 150,152 resiliently resists the movement of the shaft 130 in a respective axial direct lion. Thus, the coil springs 150,152 act to bias the shaft 130 resiliently -to a rest position. Preferably, the coil springs 150,152 are proportioned so as to allow the shaft 130 to move approximately six inches to either side of this rest position. Preferably, the spring constant of these coil springs 150,152 is in the range of 1,000 to 2,000 pounds per inch of axial travel.
Figure 3 shows a detailed view in partial cutaway of a portion of the transfer arm 30 and the shaft 130, in which it can be clearly seen that the guide structure 140 includes a bushing 144 which acts to guide the axial movement of the shaft 130 with respect to the transfer arm 30. This bushing 144 also serves as a contact surface for the coil spring 150.
Preferably, the flange 132 is welded to the shaft 130 as shown in Figure 3.
figure 4 shows a portion of a second prefer-red embodiment of this invention, corresponding to the portion of Figure 3, which differs primarily in that a number of smaller coil springs 149' are substituted for the larger concentric coil spring 150. This second preferred embodiment includes the transfer arm 30, the guide structure 140, and the shaft 130 of the first preferred embodiment. However, this second preferred embodiment includes a somewhat modified flange 132' which is welded to the shaft 130. This modified flange 132' defines a plurality of openings 147' spaced around a circle centered on the shaft 130. Each of these openings 147' serves as a guide for a respective bolt 148', each of which is screwed into a respective threaded opening in a contact surface 146'. In each I
case, a coil spring 149' is mounted concentrically around the respective bolt 148' such that it bears at one end against the contact surface 146' and at the other end against the flange 132'. This second prefer red embodiment functions identically to the first, however, since none of the coil springs 149' is consign trig with the shaft 130, the coil springs 149' is concentric with the shaft 130, the coil springs 149' can readily be replaced as necessary without disassem-bring the shaft 130 from the guide structures 140,142.
Thus, the structure of Figure 4 is readily maintained and repaired in the field..
As previously mentioned, the clamps awry rigidly mounted to respective ends of the shaft 130. These two clamps are identical in structure, and will be described in detail in connection with Figure 6, which is a cross-sectional view of clamp 122.
Before describing the clamps 120,122 in detail, it should be noted that these clamps are, with certain exceptions to be explained in detail below, identical to the clamps described in co-pending apply-cation Serial No. 182,771, filed August 29, 1980, (now U.S. Patent No. 4,366,606) assigned to the assignee of the present invention. Reference can be made to that patent for its detailed description of -this clamp.
Turning now to Figure 6, clamp 122 includes two opposed clamping members 160,162 which are goner-ally rectangular in cross-section and are mounted to slide freely within a damping member guide structure which defines two mating rectangular cavities 170,172.
The clamping members 160,162 are precisely guided by the guide cavities 170,172 such that clamping members 160,162 are restricted to movement along a straight line. The guide cavities 170,172 are formed between two parallel side plates. Only one of these side plates 174 is shown in Figure 6; however, the second side plate (not shown) is parallel]. to and spaced from the side plate 174 such that the clamping members 160,162 move between the two side plates. Rocker arms 180,182 are mounted to the clamping members 160,162 about pivot points 184,186, respectively. Each of these rocker arms 180,182 is mounted to pivot about a respective pivot 188,1~0 supported by a cross-arm 192.
In addition, a hydraulic cylinder 194 is mounted between pivot points 196,198 on the ends of the rocker arms 180,182. Thus, as the hydraulic cylinder 194 varies the separation between the pivot points 196,198 on the rocker arms 180,182, the rocker arms 180,182 are caused to pivot about the pivot points 188,190, thereby causing the clamping members 160,162 to move along the straight line defined by the guide cavities 170,172.
A centering collar 200 is rotatable mounted on a pin 202 such that the centering collar 200 is free to rotate about an axis substantially parallel to the clamped tubular 230. A pair of link members 204,206 are mounted between the centering collar 200 and the rocker arms 180,182, respectively. As shown in Figure 6, the link members 204,206 are attached to the eon-toning collar 200 at two distinct attachment points 208,210, respectively. These attachment points 208,210 are selected such that, in the view shown in Figure 6, the centering collar 200 is caused to rotate in a clockwise manner when the clamping members 160,162 are moved toward one another, and in a counterclockwise manner when the clamping members 160,162 are moved away from one another.
~3~98~1 The attachment points 208,210 as well as the lengths of the link members 204,206 are chosen such that the centering collar 200 causes the two clamping members 160,162 to be symmetrically disposed with respect to the clamping axis 212. The clamping axis 212 can be thought of as a line passing through the axial center line of a clamped Donnelly tubular. In that the clamping members 160,162 are maintained in symmetrical positions with respect to the clamping axis 212, a clamped Donnelly tubular 230 is therefore consistently clamped in a predetermined position, regardless of the diameter of the clamped tubular 230.
The pin 202 is mounted in elongated slots (not shown) defined in the side plates 174. These elongated slots are oriented with their longest dime-soon pointing towards the clamping axis 212. These slots reserve to restrict the movement of the pin 202 in a direction parallel to the direction of movement of the clamping members 160,162 while allowing limited travel of the pin 202 towards and away from the clamp-in axis 212. This limited movement is provided to accommodate the slight change in separation between the cross-arm 192 and the clamping members 160,162 as the rocker arms 180,1~2 assume varying angular positions.
As shown in Figure 6, each of the clamping members 160,162 includes a respective clamping surface 220,222. In this embodiment, each of the clamping surfaces 220,222 is formed of a wear-resistant plastic material such as a high density polyurethane. Prefer-ably, a granular abrasive, such as sand or carbide for example, is embedded in the plastic material to improve the gripping characteristics of the clamping surfaces.
The clamping surfaces are mounted to the clamping members 160,162 by means of fasteners 224.
Because the clamping surfaces 220,222 are formed of a resilient plastic material, they are adapted to engage and grip the clamped tubular 230 frictionally without guying the surface of the tubular 230 and without leaving deep clamping marks on the tubular 230. As shown in Figure 1, the clamps 120,122 are used to grip the clamped tuber 230 at inte~med~
tale positions between the tool joints 232,234. Such intermediate portions generally have thinner walls which are more easily damaged by clamps than are the tool joints 232,234. The clamps 120,122 minimize gouging and other damage to the clamped tubular 230 by providing resilient clamping surfaces 220,222 which are adapted to engage the clamped tubular 230 frictionally without leaving deep scratches or gouges. Scratching or gouging can be a significant problem with transfer arms of the prior art, foe tubular are often not precisely straight. Also, the clamped tubular 230 is subjected to large accelerations as the transfer arm 30 is moved from the lowered position shown in Figure 1 to the raised position shown in Figure lay These con-dictions can cause ordinary clamps of the type having rigid, serrated clamping surfaces to leave undesirable scratches or gouges in the intermediate portions of -the clamped tubular 230.
Referring now to Figure 5, means are provided for rotating the shaft 130 and thereby the clamps 120,122 with respect to the transfer arm 30. This rotating means includes a plate 250 which is provided with an arc-shaped cutout 252 as well as four key ways 254. The upper portion of the shaft 130 is provided with four mating keys 256 which are positioned to slide within the key ways 254 in the plate 250. The keys 256 and the key ways 254 cooperate to allow the shaft 130 I
to slide axially within the plate 250 while trays-mutating torque from the plate 250 to the shaft 130.
The plate 250 is held in place against the guide structure 1~2 by means of a pin 258 which is positioned inside the arc-shaped cutout 252 in the plate 250.
Preferably, means (not shown) are provided for adjust-in the position of the pin 258 in order to adjust the stop positions of the plate 250.
A hydraulic cylinder is positioned between an attachment point 262 in the plate 250 and the extreme end section of the transfer arm 30. This hydraulic cylinder 266 acts to rotate the plate 250 and thereby the shaft 130 through a 90 arc. The pin 252 acts as a stop which defines the two extreme rotational positions of the plate 250 and thrower the shaft 130. Figure 5 shows the pin 258 in a first position and the hydraulic cylinder 266 attached to the first attachment point 262. When so configured, the hydraulic cylinder 266 acts to rotate the plate 250 in a counterclockwise direction through an arc of 90. By merely moving the pin 258 from the position shown in Figure 6 to the alternate position 260 and then removing the hydraulic cylinder 266 from the first attachment point 262 to the second attachment point 26~, the hydraulic cylinder 266 can be made to rotate the plate 250 in a clockwise direction through an angular arc of 90.
The hydraulic cylinder 266 is used to rotate the shaft 130 and therefore the clamps 120,122 to facilitate the loading and unloading of tubular to and from the clamps 120,122. When the clamps 120,122 are rotated such that the line between the pin 202 and the clamping axis 212 is substantially horizontal, the clamps 120,122 are facing to the side, and tubular can readily be rolled into or out of the clamps 120,122.
By means of the alternate attachment points 262,264, the cylinder 266 can readily be configured to rotate the clamps 120,122 to whichever side of the transfer arm is more convenient. Conversely, when the hydraulic 5 cylinder 266 is used to rotate the clamps 120,122 to the position shown in Figures l and lay the clamped tubular 230 is positioned in line with the axis of the string 42 when the trarlsfer arm 30 is in the raised position shown in Figure lay lo The hydraulic tongs 60,70 are each self-centering clamps substantially identical in structl1re to the clamp of Figure 6. The single difference between the tongs 60,70 and the clamp of Figure 6 is that each of the tongs 60,70 is provided with a con-ventional, rigid, hard clamping surface instead of the resilient clamping surfaces 220,222 shown in Figure 6.
These rigid clamping surfaces, which bear only on the tool joints of the respective tubular, are adapted to provide a firm grip which substantially prevents a clamped tubular from rotating in the tongs 60,70.
It should be understood that the present invention is not limited to the particular type of self-centering clamp shown in Figure 6. To the con-tray, other types of self-centering clamps, such as those shown in described in co-pending patent apply-cations Serial No. 074,547, filed September if, 1979, (now U.S. Patent No. 4,303,270), assigned -to the assignee of the present invention, provide a self-centering action by means of other structures.
Having described the structure Ox the pro-furred embodiments of the drawings, the operation of this structure can now be described by tracing the steps needed to add and remove a length of Donnelly -- 19 _ tubular to a string. The first step in adding a length is to position the transfer arm 30 in the lower, substantially horizontal position shown in Figure 1 and to rotate the clamps 120,122 to the side positiorm A
length of Donnelly tubular 230 is then placed in the clamps 120,122 and the clamps are closed to grip the clamped tubular 230 securely. This clamped tubular 230 defines tool joints 232,234 at opposite ends thereof, and the lower tool joint 232 includes a threaded end 236. The transfer arm 30 is then pivoted about the pivot 34 to the raised, substantially vertical position shown in figure lay At this point, the hydraulic cylinder 266 is used to rotate the clamps 120,122 to the position shown in figure lay In this rotated position the clamped tubular 230 is aligned with the axis of the string 42.
Once the clamped tubular 230 is in the rotated position, the power swivel 50 is then lowered onto the upper tool joint 234 of the clamped tubular 230. As the power swivel 50 is lowered, the rotatable member 52 of the power swivel 50 is rotated to engage the threads of the rotatable member 52 with the threads of the upper tool joint 234. During this operation, the coil spring 150 acts to support the clamped tubular 230 resiliently such that the clamped tubular 230 is free to move downward under the axial forces applied to the tubular 230 by the power swivel 50. In this way, strain on the threads of the upper tool joint 234 it maintained at an acceptable level while the threaded connection is being made up.
In addition, the degree of compression of the spring 150 as well as the axial position of the clamped tubular 230 provide a visual indication to the operator of the drill rig as to the magnitude of the axial forces which are being applied by the power swivel 50 to the clamped tubular 230. This visual indication assists the operator in controlling the pudgier swivel 50 so as not to exert undue axial forces on -the clumped tubular 230. Because the clamped tubular 230 is free to move axially under applied forces, the precise pOSitiOIl of the power swivel 50 is less critical.
The combination of axial movement of the clamped tubular 230 as well as resilient biasing of the position of the clamped tubular 230 provides important protection to the clamped tubular, thereby making tubular handling operations less sensitive to operator error and consequently reducing operator damage to clamped tubular. In addition, the resilient clamping surfaces 220,222 of the clamps 120,122 reduce the incidence of clamping marks on the intermediate section of the clamped tubular 230 and thereby increase the useful working life of these tubular.
Once the upper tool joint 234 has been mated with the power swivel 50, the clamps 120,122 are opened and the transfer arm 30 is lowered, leaving the tubular 230 suspended from the power swivel 50. The power swivel 50 is then lowered to bring the tubular 230 into contact with the uppermost length of tubular included in the string 42. The tongs 60,70 are positioned by means of the cylinder 82 such that the upper tong 60 is positioned adjacent the lower tool joint 232 of the tubular 230, and the lower tong 70 is positioned adjacent the uppermost tool joint of the string 42.
The upper tong 60 can be closed partially about the tubular 230 to center the lower end of the tubular 230 about the clamping axis, so as properly to align the tubular 230 for mating with the string 42. The rotate able member 52 of the power swivel 50 is then rotated so as to engage the threaded end 236 of the tubular 230 with the uppermost portion of the string 42. The power swivel 50 is, however, not used to complete the mutiny of the tubular 230 with the string 42.
Rather, the tongs 60,70 are closed and then the hydraulic cylinder 100 is used to rotate the upper tong 60 so as to tighten the threaded connection between the tubular 230 and the string 42. Standard pressure regulators are preferably used to control the hydraulic pressure used to drive the hydraulic cylinder 100, and thereby precisely to control the make up torque. Once the tubular 230 is secured to the string 42, the slips 40 and the tongs 60,70 are loosened; the power swivel 50 is then used to support and rotate the tubular 230, which is now an integral part of the string 42.
When a length of Donnelly tubular is to be removed from a drill string, the above-described operations are substantially reversed. First, the power swivel 50 is used to raise the string 42 such that the uppermost tubular is raised above the carrier 10. The slips 40 are then used to support the weight of the drill string 42, and the tongs 60,70 are post-toned such that the upper tong 60 bears on the lower tool joint of the uppermost tubular of the string 42.
The tongs 60,~0 are then used to break the threaded connection between the uppermost tubular and the string, and then the swivel 50 is used to rotate the uppermost tubular and thereby to separate it from the string.
The transfer arm 30 is positioned to the vertical position and the clamps 120,122 are clamped on the uppermost tubular suspended from the swivel 50. The swivel is then rotated to break the threaded connection between the uppermost tubular and the swivel 50.
I
During this operation the upper sprint 152 resists the upward movement of the clamped tubular under the axial load applied by the swivel 50. As before, the coil spring 152 acts to allow limited axial motion and to provide a visual indication of the axial loads briny applied to the clamped Tyler In this joy, excessive forces on the threads of the upper tool joint 234 are reduced during tubular handling operations. Once the clamped tuber has been separated from the swivel 50, the transfer arm 30 is then towered to bring the clamped tubular to the position shown in Figure 1.
The tongs 60,70 provide a number of important advantages. Because each of the toys 60,70 utilizes a self-centering clamp such as the one shown in Figure 6, manual adjustment of the tongs is not required when varying size tubular are used. The combination of the transfer arm 30 and the tongs 60,70 results in a highly automated drill rig which to a great extent eliminates the need for operators to remain in dangerous positions near the moving tubular as it is installed in and removed from the drill string. This is an important safety consideration which also reduces the number of personnel required to operate the drill rig, and thereby the drooling costs.
From the foregoing, it should be apparent that an improved drill rig has been described which markedly reduces clamp damage and thread damage to clamped tubular during tubular handling operations.
In addition, this invention provides self-centering tongs which supply the torque necessary for reproduce-able and effective maze up and break out of threaded connections in a drill string, and which can be used to center and properly align lengths of tubular. Of course, it should be understood that the novel tong mounting system described above can be used with toys which do not provide a self centering function.
THE SECOND PREFERRED EMBODIMENT
Turning now to Egress 7 and 8, a second preferred embodiment of this invention will now be described.
As shown in Figure 7, this second preferred embodiment includes a swivel sub 350, which its threadedly engaged with a threaded tube 342 included in a power swivel 340. The swivel sub 350 of this invention is adapted to be threadedly connected with the upper end 332 of a clamped Donnelly tubular 330.
my way of general background, the power swivel 340 is mounted to move vertically within a drill rig mast 300. The tubular 330 is clamped in a transfer arm 310 by means of two clamps 320, the upper of which is shown in Figure 7. Figure 7 shows only portions of the drilling apparatus and the transfer arm 310, and the remaining portions which are not illustrated in Figure 7 are identical to the first preferred embodiment shown and described above. In use, the power swivel 340 operates to rotate the swivel sub 350 and thereby the tubular 330 during drilling operations.
In order to engage the tubular 330 with the power swivel 340, the power swivel 340 is used to rotate the swivel sup 350 as the swivel sub 350 is lowered onto the clamped tubular 330. In this way, the lower end of the swivel sub 350 threadedly engages the upper end 332 of the tubular 330. After this has been accomplished, the tubular 330 is then released from the clamps 320, and drilling operations continue.
The clamp 320 differs from the transfer arm clamps discussed above in that the clamp 320 is mounted Lo to the transfer arm 310 at a fixed axial position, and is not free to move longitudinally along the longitude final axis of the tubular 330.
As explained above, damage and breakage to the threads of the upper end 332 of the tubular 330 can result if the entire demurred force supplied by the power swivel 340 is brought to bear on the upper end 332 of the tubular 330 before the threaded connection is fully made up. This second preferred embodiment of the invention avoids this problem by providing an improved swivel sub 350 which includes means for resiliently allowing the effective length of the swivel sub 350 to vary within predetermined limits in order to reduce the axial forces applied to partially made up threaded joints.
Figure 8 shows a cross-sectional view of the swivel sub 350 which is made up of two major coupon-ens: an upper sleeve 360 and a lower sleeve 380. The upper sleeve 360 includes an upper collar 362 which defines an array of internal upper threads 368 adapted to threadedly engage the threaded tube 342 of the power swivel 340. The upper sleeve 360 also defines an array of internal splints 364, oriented to extend longitude finally along the length of the upper sleeve 360. An internal shoulder 366 is defined at the lower end of the internal splints 364. The upper sleeve 360 defines a lower stop surface 370 at its lowermost outer sun-face.
The lower sleeve 330 includes a lower collar 382 which is threadedly held in place at the lower end of the lower sleeve 380. This lower collar 382 defines an array of lower external threads 384 sized and shaped to threadedly engage the upper end 332 of the tubular 330. This lower collar 382 defines an upper annular extension 386 positioned around the lower sleeve 380 so as to define an annular recess 388 there between. The uppermost surface of this annular extension 386 defines a stop surface 390 which is aligned to abut the upper stop surface 370 of the upper sleeve 360.
The lower sleeve 380 defines an array of external splints 392 sized to mate with the internal splints 364. In addition, the lower sleeve 380 defines an external shoulder 394 positioned to abut the inter-net shoulder 366 of the upper sleeve 360 when the lower sleeve 380 is in a fully extended position with respect to the upper sleeve 360. A packing collar 396 is threadedly connected to the upper end of the lower sleeve 380, and the packing collar 396 defines a recess which receives an annular packing element 398. A
packing retaining ring 400 is threadedly engaged on the upper end of the lower sleeve 380 to confine the packing element 398 in place.
A coil spring 410 is positioned around the lower sleeve 380 between the lower collar 382 and the upper sleeve 360. This coil spring 410 operates to bias the lower sleeve 380 away from the upper sleeve 360 into the extended or extracted position shown in Figure 8. When compressive axial forces are applied tending to push the lower sleeve 380 into the upper sleeve 360, the spring 410 resiliently resists such retraction. However, sufficient compressive forces will cause the lower sleeve 380 to telescope within the upper sleeve 360. Thus, the splints 364,392 operate to transmit rotary motion from the upper sleeve 360 to the lower sleeve 380, while allowing the lower sleeve 380 to move axially within the upper sleeve 360. The upper and lower stop surfaces 370,390 define the maximum extent to which the lower sleeve 380 can telescope within the upper so eve Preferably, the upper and lower collars 362,382 are held in place on the resees-live sleeves 360,380 by means of a locking agent such as LACTATE in order to insure that break out does not occur.
In the preferred embodiment of Figures 7 anal 8, the lower threads 384 on the lower collar 382 are 4-1/2 inch APT IF threads. For this embodiment, the swivel sub 350 is stressed for about 500,000 pounds.
The spring 410 in this preferred embodiment provides a spring constant in the range of about 100-400 pounds per inch. The biasing force developed by the spring 410 urges the lower threads 384 of the lower collar 382 into engagement with the upper end 332 of the tubular lo 330, while allowing the lower collar 382 to be pushed upwardly as necessary to avoid thread damage to the upper end 332 of the tubular 330. In this preferred embodiment, the maximum travel of the lower sleeve 380 with respect to the upper sleeve 360 between the extended position shown in Figure 8 and the retracted position, in which the stop surfaces 370,390 are in contact, is about one and one-half times the axial make up travel when the lower threads 384 are engaged on the upper end 332 of the tubular 330. Of course, for threads larger than the awl/ inch PUFF thread described above, it may well be preferable to use a spring with a higher spring constant than that described above, and conversely, smaller spring con-slants may be suitable for smaller threads.
From the foregoing, it should be apparent that an improved swivel sub 350 has been described which acts to provide a resilient biasing force during make up operations with a clamped tubular 330. This resilient biasing force can reduce thread loading *trade mark 34~
during make up operations, and thereby reduce thread damage. Furthermore, the swivel sub 350 gives an open-atop a positive measure of the forces briny applied on threads during make up operations. In particular, the S operator can visually yaucJe the separation button the two stop surfaces 370,390 in order to determine the magnitude of forces being applied to the upper end 332 of the tubular 330. The vertical position of the power swivel 340 in the drill fly mast 300 can then be adjusted to maintain this downward force on the upper end 332 within the desired range. In this way, the need for extremely precise control of the vertical position of the power swivel 340 is largely avoided.
Of course, it should be understood that the embodiments illustrated in the drawings and discussed above are illustrative examples set forth to describe preferred embodiments of the invention in detail.
Various changes and modifications to the preferred embodiments described above can be made without depart-in from the spirit and scope of the present invention which is defined by the following claims, including all equivalents.
Claims (45)
1. In a drilling apparatus comprising a mast, a drive unit guided for travel along the mast, a transfer arm positioned adjacent the mast to move a downhole tubular between a lowered position near round level and a raised position aligned with the mast under the drive unit, and at least one clamp mounted on the transfer arm to clamp the tubular to the arm, said downhole tubular defining an upper threaded end and said drive unit defining a threaded element adapted to mate with the upper threaded end of the tubular, the improvement comprising:
means for resiliently biasing one of the tubular and the threaded element against the other when the threaded element is brought into contact and mated with the tubular, in order to permit axial movement of said one of the tubular and the threaded element along the longitudinal axis of the tubular in the raised position, thereby reducing wear and damage to the upper threaded end and the threaded element.
means for resiliently biasing one of the tubular and the threaded element against the other when the threaded element is brought into contact and mated with the tubular, in order to permit axial movement of said one of the tubular and the threaded element along the longitudinal axis of the tubular in the raised position, thereby reducing wear and damage to the upper threaded end and the threaded element.
2. The invention of Claim 1 wherein said one of the tubular and the threaded element is the tubular, and wherein the biasing means comprises:
means for mounting the at least one clamp to the transfer arm to move along an axis parallel to the longitudinal axis of the tubular; and at least one spring mounted to bias the clamp to a rest position with respect to the arm, which rest position is situated such that the tubular is biased toward the threaded element during make up operations when the arm is in the raised position.
means for mounting the at least one clamp to the transfer arm to move along an axis parallel to the longitudinal axis of the tubular; and at least one spring mounted to bias the clamp to a rest position with respect to the arm, which rest position is situated such that the tubular is biased toward the threaded element during make up operations when the arm is in the raised position.
3. The invention of Claim 1 wherein said one of the tubular and the threaded element is the threaded element, and wherein the biasing means com-prises:
means for mounting the threaded element to the drive unit such that the threaded element is movable along an axis parallel to the direction of movement of the drive unit in the mast and the threaded element is rotatable by the drive unit; and at least one spring mounted to bias the threaded element to a rest position with respect to the drive unit, which rest position is situated such that the threaded element is biased toward the tubular during make up operations when the arm is in the raised position.
means for mounting the threaded element to the drive unit such that the threaded element is movable along an axis parallel to the direction of movement of the drive unit in the mast and the threaded element is rotatable by the drive unit; and at least one spring mounted to bias the threaded element to a rest position with respect to the drive unit, which rest position is situated such that the threaded element is biased toward the tubular during make up operations when the arm is in the raised position.
4. A thread saver sub for use with a top head drive in a drilling apparatus, said saver sub comprising:
an upper sleeve adapted for connection to a top head drive to rotate about a rotational axis;
a lower sleeve which defines an array of first threads adapted for connection to a plurality of mating second threads of a length of downhole tubular, said lower sleeve coupled to the upper sleeve such that the lower sleeve rotates in unison with the upper sleeve about the axis and the lower sleeve translates with respect to the upper sleeve in a direction paral-lel to the axis between an extended position and a retracted position; and a spring interposed between the upper and lower sleeves to bias the lower sleeve away from the upper sleeve to the extended position, said spring providing a biasing force effective to protect the first and second threads when the first threads are engaged with the second threads.
an upper sleeve adapted for connection to a top head drive to rotate about a rotational axis;
a lower sleeve which defines an array of first threads adapted for connection to a plurality of mating second threads of a length of downhole tubular, said lower sleeve coupled to the upper sleeve such that the lower sleeve rotates in unison with the upper sleeve about the axis and the lower sleeve translates with respect to the upper sleeve in a direction paral-lel to the axis between an extended position and a retracted position; and a spring interposed between the upper and lower sleeves to bias the lower sleeve away from the upper sleeve to the extended position, said spring providing a biasing force effective to protect the first and second threads when the first threads are engaged with the second threads.
5. The invention of Claim 4 further comprising:
means for limiting the movement of the lower sleeve with respect to the upper sleeve such that the lower sleeve is positively prevented from moving outside the range of positions between the extended and retracted positions.
means for limiting the movement of the lower sleeve with respect to the upper sleeve such that the lower sleeve is positively prevented from moving outside the range of positions between the extended and retracted positions.
6. In a drilling apparatus having a drive unit adapted to couple to and rotate an upper end of a length of downhole tubular, the improvement comprising:
an upper sleeve adapted for connection to the drive unit to rotate about a rotational axis;
a lower sleeve which defines an array of first threads adapted for connection to a plurality of mating second threads of the downhole tubular;
means for mounting the lower sleeve to the upper sleeve such that the lower sleeve is movable along the rotational axis between a retracted position and an extended position;
means, included in the mounting means, for preventing differential rotation between the upper and lower sleeves; and means for biasing the lower sleeve away from the upper sleeve into the extended position, said biasing means providing a resilient biasing force to reduce damage to the first and second threads when the lower sleeve is mated to the downhole tubular.
an upper sleeve adapted for connection to the drive unit to rotate about a rotational axis;
a lower sleeve which defines an array of first threads adapted for connection to a plurality of mating second threads of the downhole tubular;
means for mounting the lower sleeve to the upper sleeve such that the lower sleeve is movable along the rotational axis between a retracted position and an extended position;
means, included in the mounting means, for preventing differential rotation between the upper and lower sleeves; and means for biasing the lower sleeve away from the upper sleeve into the extended position, said biasing means providing a resilient biasing force to reduce damage to the first and second threads when the lower sleeve is mated to the downhole tubular.
7. The invention of Claim 6 further com-prising:
means for limiting the movement of the lower sleeve with respect to the upper sleeve such that the lower sleeve is positively prevented from moving outside the range of positions between the extended and retracted positions.
means for limiting the movement of the lower sleeve with respect to the upper sleeve such that the lower sleeve is positively prevented from moving outside the range of positions between the extended and retracted positions.
8. A thread saver sub for use with a top head drive in a drilling apparatus, said saver sub comprising:
an upper sleeve comprising:
means for defining upper threads adapted for connection to the top head drive;
means for defining an array of internal splines oriented parallel to an axial direction; and means for defining a first shoulder below the internal spines;
a lower sleeve comprising:
means for defining lower threads adapted for connection to a length of downhole tubular;
means for defining an array of external splines sized to mate with the internal splines to allow the lower sleeve to move along the axial direction with respect to the upper sleeve while preventing differential rotation therebetween; and means for defining a second shoulder positioned to engage the first shoulder to limit movement of the lower sleeve away from the upper sleeve; and a coil spring disposed around the lower sleeve and effective to create a resilient biasing force tending to bias the lower sleeve away from the upper sleeve and the first shoulder into engagement with the second shoulder.
an upper sleeve comprising:
means for defining upper threads adapted for connection to the top head drive;
means for defining an array of internal splines oriented parallel to an axial direction; and means for defining a first shoulder below the internal spines;
a lower sleeve comprising:
means for defining lower threads adapted for connection to a length of downhole tubular;
means for defining an array of external splines sized to mate with the internal splines to allow the lower sleeve to move along the axial direction with respect to the upper sleeve while preventing differential rotation therebetween; and means for defining a second shoulder positioned to engage the first shoulder to limit movement of the lower sleeve away from the upper sleeve; and a coil spring disposed around the lower sleeve and effective to create a resilient biasing force tending to bias the lower sleeve away from the upper sleeve and the first shoulder into engagement with the second shoulder.
9. The invention of Claim 8 further com-prising:
means, included in the lower sleeve, for defining a recess sized to receive a portion of the coil spring; and means, included in the recess defining means, for defining a stop surface positioned to engage the upper sleeve to limit the movement of the lower sleeve toward the upper sleeve and thereby protect the coil spring against overcompression.
means, included in the lower sleeve, for defining a recess sized to receive a portion of the coil spring; and means, included in the recess defining means, for defining a stop surface positioned to engage the upper sleeve to limit the movement of the lower sleeve toward the upper sleeve and thereby protect the coil spring against overcompression.
10. In combination with a drilling apparatus comprising means for supporting a string of downhole tubulars on a string axis, said string including a first length of downhole tubular and a second length of downhole tubular threadedly coupled to the first length, the improvement comprising:
means for defining a guide positioned in a predetermined orientation with respect to the support-ing means;
a platform positioned to translate in the guide, toward and away from the string axis;
means for moving the platform in the guide between a storage position and a clamping position;
a first tong;
means for mounting the first tong on the platform such that said first tong is operative to clamp the first length when the platform is in the clamping position;
a second tong;
means for mounting the second tong to move with the platform such that the second tong is oper-ative to clamp the second length when the platform is in the clamping position; and means for rotating the second tong with respect to the first tong about the string axis selec-tively to tighten and loosen the threaded connection between the first and second lengths.
means for defining a guide positioned in a predetermined orientation with respect to the support-ing means;
a platform positioned to translate in the guide, toward and away from the string axis;
means for moving the platform in the guide between a storage position and a clamping position;
a first tong;
means for mounting the first tong on the platform such that said first tong is operative to clamp the first length when the platform is in the clamping position;
a second tong;
means for mounting the second tong to move with the platform such that the second tong is oper-ative to clamp the second length when the platform is in the clamping position; and means for rotating the second tong with respect to the first tong about the string axis selec-tively to tighten and loosen the threaded connection between the first and second lengths.
11. The invention of Claim 10 wherein the means for mounting the second tong comprises an arcuate guide affixed to one of the first and second tongs and an arcuate track affixed to the other of the first and second tongs and positioned such that the guide fits within and interlocks with the track to limit movement of the second tong with respect to the first tong to rotation in the arc defined by the guide.
12. The invention of Claim 11 wherein the rotating means comprises a first hydraulic cylinder connected between the platform and the second tong.
13. The invention of claim 12 wherein the platform comprises:
two telescoping, vertically oriented tubes;
and a second hydraulic cylinder disposed within the tubes to control the telescoping of the tubes and therefore the height of the platform.
two telescoping, vertically oriented tubes;
and a second hydraulic cylinder disposed within the tubes to control the telescoping of the tubes and therefore the height of the platform.
14. The invention of Claim 11 wherein the arcuate guide comprises an arcuate lug, wherein the arcuate track defines an arcuate recess sized to receive and guide the lug, and wherein the weight of the second tong holds the arcuate track and the lug in engagement.
15. In combination with a drilling apparatus comprising a mast and a transfer arm positioned adjacent the mast to move down hole tubulars between a lowered position near ground level and a raised position aligned with the mast, the improvement comprising:
at least one clamp adapted to grip a down hole tubular having at least one threaded end;
means for mounting the clamp to the transfer arm such that the clamp is movable along an axis which is substantially parallel to the longitudinal axis of a tubular clamped in the at least one clamp; and means for resiliently biasing the clamp to a rest position with respect to the transfer arm;
said mounting means and biasing means cooperating to permit movement of the clamp under axial loads applied to a clamped down hole tubular during tubular handling operations, thereby reducing wear and damage to the threaded end of the clamped tubular.
at least one clamp adapted to grip a down hole tubular having at least one threaded end;
means for mounting the clamp to the transfer arm such that the clamp is movable along an axis which is substantially parallel to the longitudinal axis of a tubular clamped in the at least one clamp; and means for resiliently biasing the clamp to a rest position with respect to the transfer arm;
said mounting means and biasing means cooperating to permit movement of the clamp under axial loads applied to a clamped down hole tubular during tubular handling operations, thereby reducing wear and damage to the threaded end of the clamped tubular.
16. In combination with a drilling apparatus comprising a mast and a transfer arm positioned adjacent the mast to move down hole tubulars between a lowered position near ground level and a raised position aligned with the mast, the improvement comprising:
a pair of clamps adapted to grip down hole tubular having threaded ends;
means for mounting the clamps to the transfer arm such that the clamps are aligned on a common clamping axis and the clamps are movable in a direction parallel to the clamping axis; and means for resiliently biasing the clamps to a rest position on the clamping axis;
said mounting means and biasing means cooperating to permit a clamped down hole tubular to move resiliently along the clamping axis under applied loads, thereby reducing wear and damage to the threaded end of the clamped tubular.
a pair of clamps adapted to grip down hole tubular having threaded ends;
means for mounting the clamps to the transfer arm such that the clamps are aligned on a common clamping axis and the clamps are movable in a direction parallel to the clamping axis; and means for resiliently biasing the clamps to a rest position on the clamping axis;
said mounting means and biasing means cooperating to permit a clamped down hole tubular to move resiliently along the clamping axis under applied loads, thereby reducing wear and damage to the threaded end of the clamped tubular.
17. The invention of Claim 16 wherein each of the clamps is provided with at least one clamping member positioned to contact a clamped tubular, and further, wherein said at least one clamping member comprises:
a resilient clamping surface secured to the clamping member to contact the clamped tubular, said clamping surface acting to engage the clamped tubular frictionally, substantially without gouging the surface of the tubular.
a resilient clamping surface secured to the clamping member to contact the clamped tubular, said clamping surface acting to engage the clamped tubular frictionally, substantially without gouging the surface of the tubular.
18. The invention of Claim 17 wherein the clamping surface comprises a plastic material.
19. The invention of Claim 18 wherein the clamping surface further comprises a granular abrasive material embedded in the plastic material.
20. The invention of Claim 16 wherein the mounting means comprises:
a shaft;
means for slideably mounting the shaft to the transfer arm such that the shaft is movable with respect to the transfer arm along a direction parallel to the clamping axis; and means for mounting the clamps to the shaft.
a shaft;
means for slideably mounting the shaft to the transfer arm such that the shaft is movable with respect to the transfer arm along a direction parallel to the clamping axis; and means for mounting the clamps to the shaft.
21. The invention of Claim 20 wherein the biasing means comprises at least one coil spring positioned to bias the shaft to a predetermined position with respect to the transfer arm.
22. The invention of Claim 20 further comprising:
means for rotating the shaft to move the clamps between at least two selected rotational positions.
means for rotating the shaft to move the clamps between at least two selected rotational positions.
23. In combination with a drilling apparatus comprising a substantially vertical mast and a transfer arm pivotably mounted adjacent the mast to transfer down hole tubulars between a lower, substantially horizontal position near ground level and an upper, substantially vertical position aligned with the mast, the improvement comprising:
a support structure slideably mounted to the transfer arm such that the support structure is slideably vertically when the transfer arm is in the upper position;
a pair of clamps adapted to clamp down hole tubulars;
means for mounting the pair of clamps to the support structure such that the clamps are aligned to clamp a tubular; and means for resiliently biasing the support structure to a rest position with respect to the transfer arm;
said clamps, support structure and biasing means cooperating to allow a clamped clown hole tubular to move axially under applied loads, thereby reducing wear and damage to the clamped tubular during handling operations.
a support structure slideably mounted to the transfer arm such that the support structure is slideably vertically when the transfer arm is in the upper position;
a pair of clamps adapted to clamp down hole tubulars;
means for mounting the pair of clamps to the support structure such that the clamps are aligned to clamp a tubular; and means for resiliently biasing the support structure to a rest position with respect to the transfer arm;
said clamps, support structure and biasing means cooperating to allow a clamped clown hole tubular to move axially under applied loads, thereby reducing wear and damage to the clamped tubular during handling operations.
24. The invention of Claim 23 wherein each of the clamps is provided with at least one clamping member positioned to contact a clamped tubular, and further, wherein said at least one clamping member coamprises:
a resilient clamping surface secured to the clamping member to contact the clamped tubular, said clamping surface acting to engage the clamped tubular frictionally, substantially without gouging the surface of the tubular.
a resilient clamping surface secured to the clamping member to contact the clamped tubular, said clamping surface acting to engage the clamped tubular frictionally, substantially without gouging the surface of the tubular.
25. The invention of Claim 24 wherein the clamping surface comprises a plastic material.
26. The invention of Claim 25 wherein the clamping surface further comprises a granular abrasive material embedded in the plastic material.
27. The invention of Claim 23 wherein the support structure comprises a shaft.
28. The invention of Claim 27 further comprising:
means for rotating the shaft to move the clamps between at least two selected rotational positions.
means for rotating the shaft to move the clamps between at least two selected rotational positions.
29. In combination with a drilling apparatus comprising a mast, a swivel mounted to move vertically in the mast, said swivel comprising a rotatable threaded member, and a transfer arm positioned adjacent the mast to move down hole tubulars between a horizontal position near ground level and a vertical position aligned with the mast, said tubulars each including a threaded end adapted to mate with the threaded end of the swivel, the improvement comprising:
a pair of clamps, each adapted to grip a down hole tubular;
means for slideably mounting the pair of clamps to the transfer arm such that both clamps are positioned to clamp a down hole tubular and a clamped tubular is free to move vertically with respect to the transfer arm when the transfer arm is in the vertical position; and means for resiliently biasing the pair of pipe clamps to a rest position;
said mounting and biasing means cooperating to permit a clamped tubular to move vertically with respect to the transfer arm and the swivel when the threaded member of the swivel is mated with and separated from the threaded end of the clamped tubular, thereby reducing wear and damage to the threaded end of the clamped tubular.
a pair of clamps, each adapted to grip a down hole tubular;
means for slideably mounting the pair of clamps to the transfer arm such that both clamps are positioned to clamp a down hole tubular and a clamped tubular is free to move vertically with respect to the transfer arm when the transfer arm is in the vertical position; and means for resiliently biasing the pair of pipe clamps to a rest position;
said mounting and biasing means cooperating to permit a clamped tubular to move vertically with respect to the transfer arm and the swivel when the threaded member of the swivel is mated with and separated from the threaded end of the clamped tubular, thereby reducing wear and damage to the threaded end of the clamped tubular.
30. The invention of Claim 29 wherein each of the clamps comprises at least two opposed clamping surfaces, wherein each of the clamping surfaces is formed of a resilient material.
31. The invention of Claim 30 wherein the resilient material comprises a plastic material.
32. The invention of Claim 31 wherein the plastic material is impregnated with an abrasive material.
33. The invention of Claim 31 or 32 wherein the plastic material comprises a high density, wear resistant polyurethane.
34. The invention of Claim 30 wherein the biasing means comprises a plurality of coil springs positioned to spring bias the movement of the clamps with respect to the transfer arm.
35. The invention of Claim 29 wherein the mounting means comprises:
a shaft;
means for slideably mounting the shaft to the transfer arm; and means for mounting the clamps to the shaft.
a shaft;
means for slideably mounting the shaft to the transfer arm; and means for mounting the clamps to the shaft.
36. The invention of Claim 35 wherein the biasing means comprises at least one spring positioned to spring bias the movement of the shaft with respect to the transfer arm.
37. In combination with a drilling apparatus comprising a mast, a transfer arm positioned adjacent the mast to move down hole tubulars between a lowered position near ground level and a raised position aligned with the mast, and at least one clamp mounted on the transfer arm to clamp down hole tubulars, the improvement comprising:
at least two opposed clamping members included in the clamp, each of said clamping members comprising a resilient clamping surface fastened to the respective clamping member and disposed to engage a clamped down hole tubular frictionally, substantially without gouging the surface of the clamped tubular, such that the clamping member and clamping surfaces securely clamp the down hole tubular as it is moved between the raised and lowered positions.
at least two opposed clamping members included in the clamp, each of said clamping members comprising a resilient clamping surface fastened to the respective clamping member and disposed to engage a clamped down hole tubular frictionally, substantially without gouging the surface of the clamped tubular, such that the clamping member and clamping surfaces securely clamp the down hole tubular as it is moved between the raised and lowered positions.
38. The invention of Claim 37 wherein each resilient clamping surface comprises a plastic material.
39. The invention of Claim 38 wherein each clamping surface further comprises a granular abrasive material embedded in the plastic material.
40. The invention of Claim 38 wherein the plastic material comprises a high density, wear resistant polyurethane.
41. In combination with a drilling apparatus comprising means for supporting a string of down hole tubulars on a string axis, said string including a first length of down hole tubular and a secondlength of down hole tubular threadedly coupled to the first length, the improvement comprising:
first self centering tong means, mounted on the drilling apparatus in alignment with the supporting means, for clamping the first length of down hole tubular against rotation, said first tong means operative to clamp the first length about a first clamping axis, aligned with the string axis, for a range of diameters of the first length without manual adjustment of the first tong means;
second self centering tong means for clamping the second length of down hole tubular against rotation, said second tong means operative to clamp the second length about a second clamping axis for a range of diameters of the second length without manual adjustment of the second tong means;
means for mounting the second tong means to the drilling apparatus such that the second clamping axis is aligned with the string axis; and means for rotating the second tong means about the second clamping axis selectively to tighten and loosen the threaded connection between the first and second lengths.
first self centering tong means, mounted on the drilling apparatus in alignment with the supporting means, for clamping the first length of down hole tubular against rotation, said first tong means operative to clamp the first length about a first clamping axis, aligned with the string axis, for a range of diameters of the first length without manual adjustment of the first tong means;
second self centering tong means for clamping the second length of down hole tubular against rotation, said second tong means operative to clamp the second length about a second clamping axis for a range of diameters of the second length without manual adjustment of the second tong means;
means for mounting the second tong means to the drilling apparatus such that the second clamping axis is aligned with the string axis; and means for rotating the second tong means about the second clamping axis selectively to tighten and loosen the threaded connection between the first and second lengths.
42. The invention of Claim 41 further comprising:
means for selectively positioning the first and second tong means at a selected one of a plurality of positions along the string axis.
means for selectively positioning the first and second tong means at a selected one of a plurality of positions along the string axis.
43. The invention of Claim 41 further comprising:
means for moving the first and second tong means between a first position, in which the first and second tong means are aligned with the string axis, and a second position, in which the first and second tong means are displaced laterally with respect to the string axis.
means for moving the first and second tong means between a first position, in which the first and second tong means are aligned with the string axis, and a second position, in which the first and second tong means are displaced laterally with respect to the string axis.
44. In combination with a drilling apparatus comprising means for supporting a string of down hole tubulars on a string axis, said string including a first length of down hole tubular and a second length of down hole tubular threadedly coupled to the first length, the improvement comprising:
first self centering tong means, mounted on the drilling apparatus in alignment with the supporting means, for clamping the first length of down hole tubular against rotation, said first tong means operative to clamp the first length about a first clamping axis, aligned with the string axis, for a range of diameters of the first length without manual adjustment of the first tong means;
second self centering tong means for clamping the second length of down hole tubular against rotation, said second tong means operative to clamp the second length about a second clamping axis for a range of diameters of the second length without manual adjustment of the second tong means;
means for mounting the first tong means on the drilling apparatus such that the first clamping axis is aligned with the string axis;
means for mounting the second tong means on the first tong means such that the second clamping axis is aligned with the string axis and the movement of the second tong means is restricted to rotation about the string axis; and means for rotating the second tong means about the second clamping axis selectively to tighten and loosen the threaded connection between the first and second lengths.
first self centering tong means, mounted on the drilling apparatus in alignment with the supporting means, for clamping the first length of down hole tubular against rotation, said first tong means operative to clamp the first length about a first clamping axis, aligned with the string axis, for a range of diameters of the first length without manual adjustment of the first tong means;
second self centering tong means for clamping the second length of down hole tubular against rotation, said second tong means operative to clamp the second length about a second clamping axis for a range of diameters of the second length without manual adjustment of the second tong means;
means for mounting the first tong means on the drilling apparatus such that the first clamping axis is aligned with the string axis;
means for mounting the second tong means on the first tong means such that the second clamping axis is aligned with the string axis and the movement of the second tong means is restricted to rotation about the string axis; and means for rotating the second tong means about the second clamping axis selectively to tighten and loosen the threaded connection between the first and second lengths.
45. The invention of Claim 44 wherein the means for mounting the second tony means comprises an arcuate guide affixed to one of the first and second tong means and an arcuate track affixed to the other of the first and second tony means and positioned such that the guide interlocks with the track to limit the movement of the second tong means with respect to the first tong means to rotation about the string axis.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US51036783A | 1983-07-01 | 1983-07-01 | |
| US510,367 | 1990-04-17 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1198411A true CA1198411A (en) | 1985-12-24 |
Family
ID=24030458
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000434212A Expired CA1198411A (en) | 1983-07-01 | 1983-08-09 | Drilling apparatus |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA1198411A (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102144072A (en) * | 2008-09-05 | 2011-08-03 | 长年Tm公司 | Feed mechanism for drilling systems |
| CN106968623A (en) * | 2017-05-24 | 2017-07-21 | 上海振华重工(集团)股份有限公司 | It is a kind of that there is the iron driller that clasp forceps is unloaded on new |
| CN114753789A (en) * | 2022-05-27 | 2022-07-15 | 吴海军 | Installation device with anti-eccentricity function for oil field Christmas tree |
-
1983
- 1983-08-09 CA CA000434212A patent/CA1198411A/en not_active Expired
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102144072A (en) * | 2008-09-05 | 2011-08-03 | 长年Tm公司 | Feed mechanism for drilling systems |
| CN106968623A (en) * | 2017-05-24 | 2017-07-21 | 上海振华重工(集团)股份有限公司 | It is a kind of that there is the iron driller that clasp forceps is unloaded on new |
| CN106968623B (en) * | 2017-05-24 | 2024-03-15 | 上海振华重工(集团)股份有限公司 | Iron roughneck with shackle clamp |
| CN114753789A (en) * | 2022-05-27 | 2022-07-15 | 吴海军 | Installation device with anti-eccentricity function for oil field Christmas tree |
| CN114753789B (en) * | 2022-05-27 | 2024-04-09 | 吴海军 | Installation device with anti-eccentric function for oilfield christmas tree |
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