Apparatus For Handling Drill Pipe

Abstract

Apparatus which transfers drill pipe between a horizontal attitude in a storage position and a vertical attitude over a well to be drilled is provided, the drill pipe being controlled during transfer by a pipe carriage riding on a fixed track.

Description

BACKGROUND OF THE INVENTION

In conventional drilling, drill pipe is ordinarily stacked in vertical stands inside the derrick as trips are made in and out of a well being drilled. This procedure, however, presents hazards when drilling from a floating vessel subject to pitching and rolling under wave action. Grave danger is presented if drill pipe stacked in the derrick suddenly shifts. In addition, vertical stacking of large quantities of drill pipe in the derrick on a floating vessel, with the resultant high center of gravity of the drill pipe, affects the stability of the vessel adversely.

Consequently, a pipe handling system which permits the storage of drill pipe in a horizontal attitude during trips in and out of the well, thereby providing a relatively low center of gravity, is desirable. Such a pipe handling system, however, must be sufficiently economic and safe for practical use. The drilling industry is well aware that the handling of drill pipe, particularly under pitching and rolling conditions, is a difficult and dangerous task.

SUMMARY OF THE INVENTION

The invention provides apparatus for transferring drill pipe between a horizontal attitude in a pipe rack and a vertical attitude above a hole to be drilled. The apparatus includes a track extending from above the floor of the derrick to a location near the outboard end of drill pipe stored in a pipe rack located alongside the derrick. A pipe-supporting truck is mounted on the track and moves along the track from above the floor of the derrick to the outboard end of drill pipe in the pipe rack. The truck has pipe gripping means pivotally mounted thereon for holding the outboard end of drill pipe in a suspended, movable position. As the inboard end of drill pipe is raised in the derrick, the truck proceeds along the track from the outboard end of the pipe rack to a location above the floor of the derrick, where the outboard end of the drill pipe may be released from the gripping means in the vicinity of the hole being drilled, and threaded on the part of the drill string already in the hole.

While coming out of the hole, the lower end of drill pipe broken from the drill string is moved into the gripping means on the truck, and the truck controls the drill pipe as the truck moves to the outboard end of the track and the upper end of the drill pipe is lowered in the derrick.

A pipe handling system in accordance with the invention permits storage of pipe in a pipe rack at a location below the track, the pipe rack having a transfer position therein from which drill pipe may be raised into engagement with the pipe gripping means on the truck.

Consequently, the invention provides a pipe handling system in which the center of gravity of pipe stored in the pipe rack can be maintained significantly below the floor of the derrick.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1, consisting of FIGS. 1A and 1B, is a schematic view of an embodiment of pipe handling apparatus in accordance with the invention; FIG. 1B extending from the left hand side of FIG. 1A.

FIG. 2 is a schematic sectional view taken along the line 2--2 in FIG. 1B.

FIG. 3 is a portion of the sectional view taken along the line 2--2 in FIG. 1B.

FIG. 4, consisting of FIGS. 4A and 4B, is a schematic view of another embodiment of pipe handling apparatus in accordance with the invention, with the components disposed as if pipe were being removed from the drilling string; FIG. 4B extending from the left hand side of FIG. 4A.

FIG. 5 is a schematic view of a portion of the apparatus in FIG. 4A, the components being disposed as if pipe were being transferred for adding to the drilling string.

FIG. 6, consisting of FIGS. 6A and 6B, is a schematic view of yet another pipe handling apparatus in accordance with the invention; FIG. 6B extending from the left hand side of FIG. 6A.

FIG. 7, consisting of FIGS. 7A and 7B, is a schematic, plan view of the pipe handling apparatus shown in FIGS. 6A and 6B.

FIG. 8 is an end view of the track construction illustrated in FIGS. 6A and 6B.

FIG. 9 is a schematic view of the pipe latch mechanism illustrated in FIGS. 6A and 6B, the view being taken from the opposite direction of that of FIG. 8.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

With reference to FIGS. 1, 2 and 3, a pipe rack 10 is located alongside a derrick 12. A track 14 extends from beyond the outboard end of the pipe rack 10 to a position above the floor 16 of the derrick 12, preferably in the vicinity of the drilling hole. Drill string 18 may be supported in the hole by conventional means, such as slips in a rotary table.

A track 20 curves from the inboard end of the pipe rack 10 to a position in the upper part of the derrick 12. The tracks 14 and 20 may be supported in their positions by conventional frames or other suitable supporting members. A truck 22 is mounted on the track 20, and the track 20 extends upwards in the derrick 12 to a location high enough to permit the truck 22 on the track 20 to maintain engagement with a multiple joint of drill pipe 24 disposed in a vertical attitude. A gripping means 30 for gripping the drill pipe 24 is pivotally attached to truck 22 by pivot shaft 32. The gripping means 30 may comprise a pipe latch 31.

A truck 34, which is movably mounted on track 14, has a pipe gripping means 36 pivotally attached to truck 34 by pivot shaft 38. Gripping means 36 includes a pipe latch 40, a supporting member or frame 42, and a pipe stop 44 attached to the supporting member 42. The pipe stop 44 is shown in position for handling pipe while coming out of the hole. When going into the hole, a removable pipe stop 46 (shown in broken lines) may be attached to the supporting member 42 to keep the pin end of drill pipe 24 at a position higher than the box end of the drill string 18, thereby permitting easier transfer of the drill pipe 24 into engagement with the drill pipe 18. With pipe stop 46 in place, the upper end of drill pipe 24, of course, will also be higher as shown by broken lines.

The drill pipe 24 in its vertical attitude, when going into the hole, may be transferred to conventional elevators from the gripping means 30 and 36 in order to move the drill pipe 24 directly over the drill string 18. After engagement with the elevators, pipe latch 31 and pipe latch 40 can be released by a person stationed near the pipe latch 31 and by another person located on the floor 16. In this case, the lower end of drill pipe 24 can be controlled manually. Alternatively, automatic devices may be provided for grasping the drill pipe 24, releasing the drill pipe 24 from the gripping means 30 and 36, and then moving the drill pipe 24 over the center line of the drill string 18.

For example, hydraulically actuated arms 48 and 50 may be disposed in the derrick to move between positions over the center line of the drill pipe 18 and the position of the drill pipe 24 in the gripping means 30 and 36. Remotely controlled pipe gripping jaws 52 and 54 are disposed on arms 48 and 50 to grip the drill pipe 24.

The arm 48 may be suitably mounted in a supporting structure 56 mounted on the derrick 12, the arm 48 being retractable to the side of the derrick 12 to clear the space in the derrick for other operations. The arm 50 is suitably mounted on a support structure 58 mounted in a track 60 on the derrick floor 16 in order that the arm 50 and the support structure 58 may be moved out of the way when not needed in the vicinity of the hole.

The gripping means 30 and 36 are held in spaced relation from one another by pipe 62 or other appropriate elongated member. In the embodiment illustrated the pipe 62 and the supporting member 42 are formed from the same length of pipe.

The truck 34 is connected to a drive truck 64 by a link 66 pivotally connected to truck 34 by pivot shaft 68 and pivotally connected to truck 64 by pivot shaft 70. Truck 64 is attached to conveyor chains 71 which are driven by a chain drive 72. The conveyor chains 71 are supported on and within box section beams 74, located on either side of the central axis of the pipe rack 10. Conveyor chain gears 76 and 78 are located at the ends of the box section beams 74 to complete the conveyor system, gear 76 being driven by chain drive 72 through belt 77. If one preferred, of course, truck 34 could be driven directly by chains 71 if chains 71 were run to the vicinity of the drilling hole.

When drill pipe is being removed from the hole, the drill string 18 is raised in the derrick 12, and the section of drill pipe 24 is broken from the remainder of the drill string 18. This operation may be accomplished by conventional devices. The drill pipe 24 is then located in the gripping means 30 and 36 in vertical attitude, either manually or by actuation of suitable devices such as arms 48 and 50. When the drill pipe 24 is firmly latched in the gripping means 30 and 36, the chain drive 72 is actuated to move the truck 64 away from the derrick 12 along the track 14, the truck 64 being attached to the conveyor chain 71 in a non-slipping relationship. As the truck 64 moves outward from the derrick 12 on the track 14, the truck 34 and the truck 22 follow because of connection through link 66 and pipe 62. An intermediate traveling position is illustrated in FIG. 1 in broken lines. As there shown, the top end of the drill pipe 24 has descended toward the floor 16 of the derrick 12, as the bottom end of drill pipe 24 has moved away from the floor 16.

Drive truck 64 continues out track 14 until it reaches its outboard position, at which time the chain drive 72 stops. In this position, the drill pipe 24 is suspended in horizontal attitude and is disposed above a transfer position 80 in the pipe rack 10, which is formed by V-shaped heads 83 and 85 on hydraulic lifting cylinders 82 and 84 in retracted position. On actuation, the heads 83 and 85 move upwardly until drill pipe 24 rests thereon. The gripping means 30 and 36 are released, and the heads 83 and 85 are retracted to a transfer position 80. Additional lifting cylinders, of course, may be disposed under drill pipe 24 to provide sufficient support without undue bending.

A second hydraulic lifting cylinder 86 supports cylinder 84 to permit retraction of cylinder pivotally below its normal pipe-supporting position and allow the outboard end of the drill pipe 24 to swing past the cylinder 84 as the drill pipe 24 is raised or lowered along the tracks 14 and 20.

With particular reference to FIG. 2, the track 14 comprises two spaced tubular rails 88 and 90 on which the trucks 34 and 64 ride. The track 20 comprises two parallel tubular rails 92 and 94 on which the forward truck 22 rides. The space between the rails 88 and 90, as well as between the rails 92 and 94, is maintained free of obstruction in order that the drill pipe 24 may pass between the rails and consequently pass by the track as drill pipe is raised or lowered. In this regard, it should be noted that the frame of the pipe rack which supports the rails is discontinuous along the path between the transfer position and a horizontal plane passing through the spaced rails.

Although an automated system is preferable, pipe may be transferred between the transfer position 80 in the pipe rack and the pipe storage area by any suitable system.

The automated system best shown in FIGS. 2 and 3 comprises a series of vertical conveying screws 100 which are capable of raising pipe from storage positions in pipe bins 101 up to a level where a horizontally disposed conveying screw 102 moves pipe in a horizontal attitude toward transfer position 80 in the pipe rack 10. On the other side of the pipe rack 10 a horizontally disposed conveying screw 104 moves pipe from that side of the rack toward the transfer position 80. A series of vertically disposed conveying screws 106 is located on this side of the pipe rack 10 to move pipe located in bins 108 up to a level where the conveying screw 104 can engage the drill pipe and move the pipe to the transfer position 80.

By reversing the direction of the conveying screws, pipe can also be moved to the storage bins of the pipe rack 10 from the transfer position 80. The conveying screws are of course mounted securely, such as by journal bearings 105, to permit operation under the loads involved. Each conveyor screw may be powered by a suitable power source, such as a hydraulic or electric motor.

Three sets of the conveying screw arrangement illustrated in FIG. 2, or some other suitable number, may be disposed along the length of the pipe rack in order to move the drill pipe between the storage area of the pipe rack and the transfer position 80, while providing sufficient spacing of forces on the drill pipe being moved. In order to compensate for end-wise thrust due to the rotary action of the conveyor screws when propelling a stand of pipe in the vertical and horizontal directions, one set of conveying screws utilizes screws with a left-hand helix, while the other two sets of conveyors may have screws with a right-hand helix. Additional compensation may also be obtained by adjusting the spacing between the conveyor sets to control the amount of deflection in the unsupported spans of drill pipe.

Thus, when the pipe rack is full and when going into the hole, pipe moves from the pipe rack to the transfer position 80 and is then moved up into engagement with the gripping means 30 and 36. Once the drill pipe is engaged with the gripping means 30 and 36, the drill pipe 24 is moved to a vertical attitude within the derrick 12 as described earlier. This phase of the operation starts with the taking of drill pipe from a vertical storage bin nearest the transfer position of the pipe rack 10. When this storage bin has been emptied of pipe, pipe is then taken from the vertical storage bin next nearest to the transfer position 80, etc. The rotation of the vertical and horizontal screw conveyors may be synchronized to assure that once a line of pipe is being moved, each rotation of the conveying screws expels a stand of pipe onto the transfer position 80. At that point, the V-block heads 83 and 85 of the hydraulic lifts 82 and 84 may be actuated to force the drill pipe 24 into engagement with the gripping means 30 and 36 attached to the trucks 22 and 34.

When coming out of the hole, after the trucks 22 and 24 have come to rest over the transfer position 80 in the pipe rack 10, the pipe is released to the lifting cylinders 82 and 84, the cylinders are retracted to place the pipe in transfer position 80, and the pipe is then transferred back to the storage position in the pipe rack. When coming out of the hole, of course, the first stand of pipe out of the hole will be placed in the farthest position of the pipe rack and pipe then added thereto successively, working back from the farthest position.

FIG. 3 is a partial section of the central portion of the pipe rack 10 illustrated in FIG. 2, the section in this figure being taken just to the rear of the gripping means 36 of truck 34 as illustrated by the line 2--2 in FIG. 1. As there shown, the lifting cylinder 82 has a V-block head 83 providing a transfer position 80. Drill pipe 24 to be transferred has an enlarged diameter 25 at its box end. Drill pipe moves to this transfer position 80 from the storage bins 101 by actuation of the vertical conveying screws 100, which move the pipe in one bin vertically where horizontal conveyor screw 102 engages with a stand of pipe and moves it horizontally toward transfer position 80.

One revolution of the horizontal conveyor screw 102 moves the pipe one position horizontally and one revolution of the vertical conveyor screw 100 moves the pipe one position vertically to engage the horizontal conveyor screw immediately behind the preceding drill pipe. A spacer block 110 is located within each pipe storage bin 101 in order to provide a closure at the top of the storage bin 101 when emptied of drill pipe. The spacer block 110 permits the pipe from the next succeeding bin 101 to pass over the opening of a storage bin 101 closer to the center of the pipe rack 10.

When going into the hole, the line of pipe within the engagement of the horizontal conveyor screw 102 will force the pipe beyond the end of the screw (shown by broken lines) onto the transfer position 80. When returning pipe to the pipe rack a hydraulic thrust cylinder 112, several being located along the drill pipe 24 on the transfer position 80, will upon actuation push the pipe 24 away from the V-block head 83 onto the slight inclined plane of the pipe rack support 114, where the drill pipe will roll by gravity into engagement with the horizontal conveying screw 102.

The gripping means 36 located above the lifting cylinder 82 includes a pipe latch 40 comprising a plate 116 having a slot 118 therein with cam surfaces 120 at the bottom of the plate 116 leading toward the slot 118. The slot 118 is slightly larger than the diameter of the drill pipe. A locking arm 122 is attached to the plate 116 by pivot shaft 123, which is located above one side of the slot 118. A spring 124 is attached to the locking arm 122 and the plate 116 to bias the locking arm 122 in a closed position over the slot 118. The locking arm of course may take various shapes and may be pivoted on the plate 116 at various locations, such as above the middle of slot 118, depending on the particular latching operation desired.

The inner pipe-bearing surface 126 of the locking arm 122 extends from near the pivot shaft 123 across the slot 118 and then curves back to approximately the side of the slot 118 below the pivot shaft 123. In this position, the slot is closed and the pipe 24 is held within the pipe latch. The bottom outer surface of the locking arm 122 has a cam surface 128, which cooperates with a drill pipe 124 when moved forcibly up against the cam surface 128 to move the locking arm 122 away from the slot 118.

The V-block head 83 of the lifting cylinder 82 includes an auxiliary hydraulic cylinder 130 which engages a ridge 132 on the locking arm 122 and moves the locking arm up and away from the slot 118 to the position indicated by the broken lines. Such an auxiliary cylinder may be suitably disposed at each location where the pipe latch of either gripping means 30 and 36 may be required to be opened, such as on the arms 48 and 50 in the derrick 12. Alternatively, a lug or similar extension may be provided on the locking arm 122 for accepting a lever and permitting release of the latching mechanism by movement of the lever. A raised stop 134 on the plate 116 precludes the locking arm from rotating too far.

A pivot shaft 38 connects the gripping means 36 to the frame of the truck 34. Also attached to the frame of the truck 34 is a wheel 136 which rides on the tubular rail 88. The wheel 136 is mounted on a shaft 138 which passes through the frame of the truck 34 to the other side to another wheel (not shown) which rides on tubular rail 90. The wheel 136 is preferably in the shape of a spool with two opposing beveled surfaces 135 and 137 mating with the tubular rail 88.

A wheel 140 mounted on a shaft 142 rides under the rail 88 and keeps the wheel 136 from jumping off the rail 88. The shaft 142 is attached to the truck 34 and carries a corresponding wheel (not shown) which rides under the tubular rail 90. Truck 34 has a total of four wheels similar to wheel 136 spaced thereon for stability in riding on the tubular rails 88 and 90. A total of four wheels corresponding to wheel 140 are located under each of the wheels 136.

Truck 22 has gripping means 30 connected to its frame by means of pivot shaft 32, gripping means 30 having a construction like that described for gripping means 36. Truck 22 also has wheels 144 and 146 mounted on shafts 148 and 150 in a manner similar to those with respect to truck 34. The drive truck 54 is constructed similar to truck 34, except that drive truck 64 does not have a gripping means associated with it.

The foregoing equipment may be suitably automated to permit rapid, yet safe transfer of drill pipe between a horizontal attitude in a pipe rack and a vertical attitude in a derrick. The system permits use of a remotely controlled, power-actuated elevator and the other components normally associated with a manually controlled, rotary drilling rig. It should be noted that the drill pipe is constrained during transfer to avoid sudden or unexpected movement. The system also permits drill collars to be stored when not in use in conventional fingers provided in derricks for vertical stacking.

Another embodiment in accordance with the invention is illustrated in FIGS. 4 and 5. A pipe rack 160 is disposed adjacent a derrick 162 which has a floor 164. A drill string 166 is disposed within the hole to be drilled and is supported by slips in the rotary table or by other suitable manner.

A track 168 is mounted on suitable support members and extends from above the floor 164 of the derrick 162 to a position near the outboard end of the pipe rack 160. The track 168 comprises two parallel, horizontally displaced channel beams, or other suitable members such as I-beams. A truck 170 is disposed between the beams with four wheels 172 mounted on the truck 170 in a conventional manner for riding on the inner bottom surfaces of the I-beams.

The truck 170 has a pipe gripping means 174 pivotally connected to the truck by a pivot shaft 176. The gripping means 174 includes a frame 178, a pipe stop 180 attached to the frame, a pipe latch 182, and a pipe guide 184. The pipe latch 182 is constructed in the same manner as illustrated in FIG. 3 for pipe latch 40. Pipe guide 184 is a plate with a slot somewhat wider than the drill pipe to be guided, the slot having cam surfaces leading into the slot. Pipe stop 180 may be simply a plate depending from the frame 178.

Mounted on the frame 178 is a wheel 186 which when mated with inclined surface 188 on the track 168 rotates the gripping means 174, as the truck 170 moves to the end of track 168, into a position for acceptance of vertically disposed drill pipe. When coming out of the hole, elevators 190 attached to a hook block 192 may be employed to pick up the drill string 166 in the hole to a position where a stand of drill pipe 194 is to be broken from the drill string. After the stand of drill pipe has been broken from the drill string, the stand of drill pipe 194 is moved over to engagement with the latching mechanism 182 on the gripping means 174. This step may be accomplished manually or mechanically. The pipe stop 180 keeps the stand of pipe from passing beyond the gripping means 174.

Although elevators 190 and hook block 192 are illustrated as conventional items, any other suitable means for raising and lowering drill string may be employed. As illustrated, two joints of drill pipe 194 are broken from the drill string 166 at one time. One joint or more, of course, may be broken and handled at one time depending on the size of the equipment and the ability of the stand of drill pipe to withstand bending stresses as it moves between vertical and horizontal positions.

Truck 170 is attached to cable 196 by any suitable means such as a clamp 198. Cable 196 passes over end sheaves 200 and 202 mounted suitably on the frame which supports an I-beam of track 168. Cable 196 passes over directional sheaves 204 and 206 and around power sheave 208. Consequently, truck 170 can be moved to any position along track 168 by actuation of power sheave 208 in the direction desired. Preferably, a second drive cable (not shown) is connected to truck 170 near the other side of the track to maintain even movement of the truck 170 along the track 168 without tendency to bind in the track.

As drill pipe 194 is removed from the derrick, truck 170 is powered away from the derrick 162 along track 168. The truck 170 with drill pipe 194 suspended from the elevators 190 is illustrated in an intermediate position in broken lines.

A second track 210 is constructed in a manner similar to the first track 168 and has a truck 212 mounted thereon in a manner similar to the way truck 170 is mounted on track 168. The truck 212 has a pipe supporting cradle 214 pivotally mounted threon by pivot shaft 216. The cradle 214 comprises a frame having two upwardly facing plates with pipe accepting slots in each of the plates. Truck 212 is connected to drive cable 218 by cable grip 220. Cable 218 passes around end sheaves 222 and 224, over directional sheaves 226 and 228, and around power sheave 230. Consequently, actuation of power sheave 230 will move truck 212 along the track 210.

As the box end (inboard end) of the drill pipe 194 nears the floor 164 of the derrick 162, and the truck 170 is continuing out on the track 168, the truck 212 is moved into a position (shown in broken lines) along the track 210 over the floor 164 whereby the inboard end of the drill pipe 194 may come to rest on the cradle 214 of the truck 212. If the box end is not against the cradle 214 continued movement of truck 170 will slide the box end of pipe 194 against the cradle.

Truck 170 continues movement out the track 168 until it reaches its selected outboard position and the truck 212 is in the position shown in FIG. 4. Hydraulic lifts 232, 234, and 236 are disposed under the drill pipe 194 in this lowered position. Lift 236 upon actuation will raise the inboard end of drill pipe 194 off the cradle 214 to a position for transferring the drill pipe 194 to a storage position in the pipe rack.

Hydraulic lift 232 carries a suitable means for releasing the pipe latch 182, such as the auxiliary cylinder previously described. Upon actuation, lift 232 extends up to the pipe 194 in the pipe latch 182, releases the pipe latch, and accepts the pipe 194 from the pipe latch 182. Hydraulic lift 234 may be suitably actuated to provide support for the pipe 194 and to keep the pipe 194 from bending unduly, the lifts 232, 234, and 236 being controlled in relation to one another.

The lifts are then actuated to reach a position where the drill pipe 194 may be transferred to a storage area. The drill pipe may be transferred to the storage area manually or preferably by suitable pipe conveying means, such as the conveying means described hereinbefore.

When going into the hole, the drill pipe 194 is taken from the transfer position by the lift cylinder 232 raising the pipe 194 into engagement with the pipe latch 182 and lift 236 lowering the drill pipe 194 onto the cradle 214. The power sheaves 230 and 208 are then energized to take the pipe toward the center of the derrick for engagement by the means in the derrick for raising and lowering drill pipe.

As better shown in FIG. 5, the pipe 194 on the cradle 214 is shown by broken lines at a position over the floor 164. The pipe 194, as truck 170 continues to be powered, slides along the cradle over the hydraulic lift 238 which has two rollers 240 mounted on its head to form a V-shape. As the pipe 194 slides past the V-shaped rollers 240, the cylinder 238 is actuated to raise the pipe 194 to a position where the elevators 190 may be set around the box end of the pipe 194. At this point, the hook 192 is raised in the derrick as the truck 170 moves along the track 168. As the truck 170 reaches the innermost end of the track 168, the driller will stop the rise of the pipe 194 in the derrick, and an operator on the floor can release the pipe latch 182. The pipe 194 is available in the immediate vicinity of the hole to be added to the drill string 166.

With reference to FIG. 5, conventional center latch elevators 190 may be modified by adding opposing cam surfaces 191 on opposite sides above the latch thereof. The cam surfaces 191 permit the elevators in opened position to be moved into position under the drill pipe for pick-up. The surfaces 191 keep the elevators open as the hinged portion abuts the drill pipe during pick-up. As upwards motion continues, the elevators will rotate until the latch portion is above the drill pipe where the latch will close automatically.

A control panel or console may be located on the derrick floor for controlled operation of the horizontal pipe racker and the two trucks of the pipe handling mechanism. In addition, various phases of the procedure may be controlled automatically, or at least semi-automatically, by the driller (control panel operator).

For example, when going into the hole, the driller may direct the two pipe trucks 170 and 212 to their rack loading positions and then command the mechanical transfer mechanism in the pipe rack 160 to discharge a stand of pipe. The latter command may automatically cause the three axially disposed hydraulic cylinders 232, 234, and 236 to be subsequently actuated to load this stand onto the upper and the lower trucks 170 and 212. The driller using the control panel can then direct the trucks 170 and 212 toward the derrick which command may automatically declutch the power sheave 208 of the upper truck 170 and drive the lower truck 212 forward. As the lower truck 212 approaches its terminus, a sensor may be engaged to cause the power sheave 230 to be declutched and the upper truck power sheave 208 to be simultaneously engaged to continue to propel the stand of pipe forward, sliding the pipe through the cradle 214. When the tool joint (box end) passes over the roller type V-shaped lifting cylinder 238, still another sensor may be engaged causing the cylinder 238 to be energized to lift the stand off the lower truck 212, but permitting the forward motion to continue until the upper truck 170 engages a sensor on its track 168. This sensor may stop the forward motion of the pipe, declutch the upper truck 170 from its power sheave 208, and direct the lower truck 212 to its track-loading (outboard) position. With this sequence completed, the stand is in a substantially horizontal attitude with its box end located just above the elevators 190, as illustrated in FIG. 5.

During a portion of the time the procedure just described has been taking place, the stand of pipe last added to the drill string 166 can have been lowered into the well bore and set on rotary table slips 193, the elevators 190 in this position being illustrated in broken lines in FIG. 5.

To continue the above sequence, the driller lowers the block 192, and the crew breaks the elevators 190 from the box end of the last stand on the drill string 166. The driller then lifts the elevators 190 causing them to engage and close on a new stand of pipe and as the upward motion is continued, the elevators 190 lock onto the new stand and raise the stand into the derrick. When the stand approaches the vertical, the upper truck 170 approaches the end of its track 168 and comes to rest in a stable position. An important feature of the present invention is that in the event of overtravel of the elevators 190, the bottom end of the stand of pipe 194 is harmlessly raised within the confines of the gripping means 174 of the truck 170. At the same time, the gripping means 174 still holds onto and constrains the stand of pipe.

At this point, the crew is able to grasp the stand of pipe 194, release the gripping means 174 of pipe truck 170, and guide the pin end of the pipe 194 into the box connection of the drill string 166 as the driller lowers the elevators 190. While this tool joint connection is being made up, the driller can direct both pipe trucks 170 and 212 to their outboard positions for accepting another stand of pipe and repeating the cycle.

When coming out of the hole, the driller directs the upper pipe truck 170 to its inboard position where it remains until loaded with a stand of pipe mechanically or by a crew. After loading, the upper truck 170 can be directed by the driller outwardly along the track 168 while the elevators 190 is lowered. When the upper truck 170 passes a position where it need be driven no longer, it may actuate a sensor which declutches the upper truck power sheave 208 and, at the same time, starts the lower truck 212 toward its inboard, derrick-loading position, When the lower truck 212 reaches its derrick-loading position, it can actuate another sensor which energizes the roller type V-shaped lifting cylinder 238. Thus, as the driller continues lowering the elevators 190, the stand of pipe approaches a horizontal attitude and comes to rest on the roller type V-shaped lifting cylinder 238. The driller then stops the travel of the elevators 190, which are broken open by a crew or otherwise, and lifted off the pipe. The driller then directs the upper truck 170 to its outboard position by actuating power sheave 208. This command, simultaneously, can retract the roller type V-shaped lift cylinder 238 and declutch the power sheave 230 of the lower truck 212. When the upper truck 170 reaches its outboard terminal, it actuates a sensor which declutches its power sheave 208 and, at the same time, actuates the three axially disposed lifting cylinders 232, 234, and 236. The cylinders move to unload the trucks 170 and 212 and then to locate the pipe at the elevation of the transfer position in the pipe rack 160. When the stand comes to rest at the transfer position another sensor can be actuated to cause the stand of pipe to be transferred to a storage position in the pipe rack 160.

During a portion of the time this procedure has been taking place, the crew will have installed the elevators 190 on the next stand of pipe to be pulled from the well bore and it will have been lifted into the derrick. This cycle can be repeated as many times as necessary to lay all of the drill pipe down.

With reference to FIGS. 6, 7, 8, and 9, yet another embodiment of pipe handling apparatus in accordance with the invention is illustrated. As there shown, a pipe rack 250 is disposed alongside the floor 252 of a derrick. Drill string 254 is suspended in rotary table 256 by conventional means, such as slips. A track 258 is disposed alongside the derrick floor 252 and extends from above the floor 252 outwardly above the pipe rack 250. The track 258 is disposed to run along the center of the pipe rack 250, and is constructed from two oppositely disposed channel beams 260 and 262.

The beams 260 and 262 are mounted in parallel relationship on the longitudinal supports 264 and 266 which in turn are mounted on the main frame 268 of the pipe rack 250 by suitable supporting elements. The space between the beams 260 and 262 and between the supports 264 and 266 are maintained free of obstruction in order that pipe may move vertically therebetween. In addition, the main frame 268 of the pipe rack 250 may include spaced longitudinal beams or supports 263 and 265 which support vertical elements 267. Vertical elements 267 support in turn the longitudinal supports 264 and 266. Longitudinal beams 263 and 265 may be supported by horizontal members 269 which are in turn supported by vertical supports 271, thereby leaving an opening 270 in the main frame 268 for passage of pipe. Consequently, pipe located under the horizontal members 269 may be moved to the transfer position and then moved upwardly into engagement with the truck 274 without obstruction by any elements of the main frame 268. Other suitable frame designs could of course be employed.

With particular reference to FIGS. 6 and 7, a pipe supporting truck 274 is mounted on the track 258 between the channel beams 260 and 262. The truck has two wheels 276 and 278 which ride in the channel beam 260, and two wheels 280 and 282 which ride in the channel beam 262. The wheels are suitably disposed at the four corners of a frame 284 of the truck 274. With particular reference to FIG. 9, two plates 286 and 288 are mounted on the frame 284 such as by welding, and extend in front of and downwardly from the frame 284. A pipe gripping means 290 is pivotally mounted on the plates 286 and 288 through trunnions 292 and 294.

The pipe gripping means 290 comprises a frame 296, a depending plate 298 at an outboard position of the gripping means 290, a pipe latch 300 depending from a central portion of the frame 296, and a pipe guide 302 depending from the inboard position of the frame 296. The pipe guide may conveniently take the form of a slot in a depending plate, the slot having a width somewhat wider than the diameter of a drill pipe and having cam surfaces leading to the slot. Mounted on the inboard end of the pipe gripping means 290 is a cam roller 307.

Truck 274 is propelled along the track 258 by a cable drive, or other suitable drive means. The cable drive comprises end sheaves 304 and 306 mounted along one side of the track 258 and sheaves 308 and 310 mounted along the other side of track 258. Between the end sheaves 304 and 306 is a directional sheave 312; between end sheaves 308 and 310 is a directional sheave 314. Below directional sheave 312 is a power sheave 316 which is driven through a suitable clutch mechanism by a reversible hydraulic motor 318. A power sheave (not shown) is disposed under the directional sheave 314 on the same shaft as the power sheave 316. Consequently, when the hydraulic motor 318 is actuated, the power sheave 316 and its corresponding sheave on the opposite side drive cables 320 and 322 mounted on the sheaves. Directional sheaves 312 and 314 are preferably three groove sheaves and the power sheaves 316 and the other one not shown are preferably two groove sheaves to permit the cable being wrapped between the directional sheaves and the power sheaves two complete loops to minimize slippage between the cables 320 and 322 and the power sheaves.

The cable 322 passes underneath the top leg of channel beam 324, which supports the channel beam 260, and returns underneath its bottom leg. Similarly, the upper portion of cable 320 passes underneath the upper leg of channel beam 326, which supports channel beam 262, and the lower portion rides underneath the lower leg of channel beam 326.

The truck 274 has two extensions 328 and 330 mounted to either side thereof which are attached to cables 322 and 320 respectively. These extensions extend out beneath the beams 324 and 326 and ride thereunder along the track 258. Consequently, upon actuation of hydraulic motor 318 the truck 274 can be propelled along the track 258.

The pipe latch 300 on the truck 274 is illustrated in FIG. 9. As there shown, it comprises a plate 332 which has a slot 334 extending upwardly from the bottom of the plate 332, the slot 334 having a width slightly larger than the outside diameter of drill pipe, but smaller than the outside diameter of the tool joint. Cam surfaces 336 and 338 lead to the slot 334.

A locking arm or latch bar 340 is pivotally attached to the plate 332 by pivot shaft 341. The pivot shaft 341 is located above one side of the slot 334, and the inner pipe bearing surface 342 of the locking arm 340 extends across the slot 334 from near the pivot shaft 340 to the other side of the slot 334 and then curves back underneath a drill pipe when located therein to approximately the first side of the slot 334. The outer bottom surface of the locking arm 340 includes a cam surface 344 which when drill pipe is pushed upwardly against cam surface 344 cooperates to rotate the locking arm away from the slot 334 and thereby open the latch.

The locking arm 340 extends beyond the pivot shaft 341 for a short distance to form a lever arm 343. A pivot shaft 346 connects a link 348 to the lever arm 343. The link 348 is pivotally linked to bar 350 by another pivot shaft 352. The bar 350 is pivotally mounted on the plate 332 by shaft 354.

The shaft 354 rotates in regard to the plate 332, but is bound to the bar 350 by friction mechanism 355 to prevent rotation between the bar 350 and the shaft 354. As better shown in FIG. 6, the shaft 354 extends behind the plate 332 a significant distance. Attached to the shaft 354 are links 356 and 358 in spaced relationship, which carry a bar 360 connecting them. The shaft 354 and the links 358 and 356 may be welded together in a fixed relationship. The bar 360 is located over a hydraulic lift 362 mounted on a suitable frame of the pipe rack 250. Consequently, actuation of the hydraulic lift 362 will rotate the bar 350 about the axis of the shaft 354, forcing the other end of the bar 350 down at the pivot shaft 352. In turn, the lever arm 343 will be forced downwardly and the locking arm 340 will rotate about the pivot 341 to open the slot 334. A lug 364 is attached to the plate 332, and a spring arrangement 366 is attached therethrough to bar 350 by pin 367 to bias the bar 350 in an upward position, thereby force the lever arm 343 upwardly, and thereby maintain the locking arm 340 in a position closed over the slot 334.

With particular reference to FIGS. 6 and 7, a stand of drill pipe 368 is illustrated in a transfer position in the pipe rack 250. The pipe rack 250 may have automatic means therein for moving the drill pipe 368 to and from storage positions in the pipe rack 250 or the drill pipe 368 may be moved to this transfer position under the track 258 in any suitable manner, such as manually.

Drill pipe 368 may be transferred from horizontal attitude in the transfer position to a vertical attitude above the floor 252 of a derrick in the following manner.

An arm 369 is pivotally connected to the frame of the pipe rack 250 by a pivot shaft 370 or by other suitable means. In preferred practice, the arm 369 will have a Y construction with two points of the Y being pivotally mounted on the frame of the pipe rack 250. The arm 369 includes a pipe cradle 372 pivotally mounted thereon, the cradle 372 fitting under the drill pipe 368. The arm 369 may also include means for aligning the drill pipe 368 appropriately beneath the truck 274 in its outboard position. In this regard, the arm 369 may include a pipe cradle 376 connected to the arm 369 through a pivot shaft 378, and a hydraulic lift 380, which upon actuation will move the pipe cradle 376 to move drill pipe 368 into abutment with a pipe alignment stop 374.

The arm 369 is pivotally connected to a hydraulic lift 382 which in turn may be pivotally connected to a support member 384. Consequently, upon actuation of hydraulic lift 382 the arm 369 will rotate upwardly and force the outboard end of drill pipe 368 into engagement with the pipe latch 300 on the pipe gripping means 290. The lift 382 and thus the arm 369 may then be retracted.

With the pipe 368 held by the pipe gripping means 290, the inboard end of drill pipe 368 rests on roller 386, the roller 386 being located to support the inboard end of the pipe 368 when the outboard end of the pipe 368 has been raised from the transfer position in the pipe rack 250 into engagement with the pipe gripping means 290.

The hydraulic motor 318 is then actuated to move the truck 274 toward the floor 252 of the derrick. As this motion progresses, the inboard end of the drill pipe 368 is supported by another roller 388 inboard of the roller 386 and located at a somewhat lower position. As the truck 274 continues toward the derrick floor 252, the inboard end of the drill pipe 368 passes across roller 390. The proper elevation of rollers 388 and 390 in relation to roller 386 may be determined by the length of the drill pipe 368, the angles involved, and the amount of deflection or bending in the drill pipe 368 during this particular movement and the reverse of the movement.

As the pipe reaches the roller 390, the roller 390 moves upwardly to support the inboard end of the drill pipe 368 in a higher position for convenient handling on the derrick floor 252, as illustrated by broken lines in FIG. 6A.

The inboard end of the drill pipe may be raised into a convenient location in a number of ways, but the apparatus illustrated in the drawing is suitable. As there shown, the roller 390 is mounted on a frame 392. Frame 392 is pivotally connected to links 394 and 396 and to corresponding links 398 and 400 on the other side. Each of the links 394, 396, 398 and 400 are pivotally connected to a fixed support. A hydraulic lift 402 is pivotally connected to a link 404. Link 404 is fixedly connected to links 394 and 398. Consequently, upon actuation of hydraulic lift 402, the links 394 and 398 will be raised around the axis on which they are attached to the fixed support, and the frame 392 will be rotated upwardly and toward the derrick floor 252, the links 396 and 400 rotating upwardly as they follow the force applied to the links 394 and 398.

After the inboard end of the drill pipe 368 is in a convenient location over the derrick floor 252, the inboard end is connected to elevators or other suitable means located in the derrick, and the inboard end of the drill pipe 368 is then raised in the derrick as the truck 274 continues toward the derrick floor 252. As the drill pipe 368 is raised in the derrick, the gripping means 290 will assume a vertical position as illustrated by broken lines in FIG. 6A. At this point, the pipe latch 300 is released, either manually or mechanically, by pushing on bar 360 of the latch mechanism, and the pin end of the drill pipe 368 is available for connection with the drill string 254.

When coming out of the hole, the truck 274 is powered to its inboard position. A cam surface 406 is provided at the inboard end of the track 258 to mate with the cam roller 307 and orient the pipe gripping means 290 in a vertical attitude for acceptance of vertically disposed drill pipe. As a drill pipe 368 is broken from the drill string 254, the pin end of the drill pipe 368 is moved over into engagement with the pipe latch 300, either manually or mechanically, and the truck 274 is powered away from the derrick floor 252 as the pipe 368 is lowered in the derrick. As the upper box end of the drill pipe 268 approaches the derrick floor 252, the roller 390 on frame 392 is rotated upwardly to accept the inboard end of the drill pipe 368. The truck 274 is stopped while the elevators or other raising and lowering means is removed from the box end of the drill pipe 368. After disengagement, the truck 274 is again powered by actuation of hydraulic motor 318, the roller 390 on frame 392 is rotated downwardly, and the truck 274 continues to its outboard position pulling the inboard end of the drill pipe 368 with it across the rollers 390, 388 and 386. At this point, the arm 369 is moved upwardly into engagement with the drill pipe 368, the hydraulic lift 362 is actuated to release the pipe latch 300 by movement of the bar 360, and the arm 369 is then retracted to locate the drill pipe 368 in the transfer position associated with the pipe rack 250. From this transfer position, the drill pipe 368 can be transferred either manually or mechanically to a storage position in the pipe rack 250.

The various steps and movements described herein can of course be automated by use of suitable sensing devices located at appropriate positions to provide a virtually automatic system for transferring drill pipe between a vertical attitude in a derrick and a horizontal attitude in a pipe rack located near the derrick. Pipe handling apparatus in accordance with the invention also permits the storage of drill pipe at a relatively low center of gravity when the apparatus is used on off-shore drilling vessels. The invention also provides a relatively safe system for transferring drill pipe, since uncontrolled movements of drill pipe, which frequently lead to serious injury and substantial damage, are minimized.

The apparatus illustrated herein have tracks which have a downward inclination as they extend away from the derrick floor to keep the center of gravity of the pipe rack relatively low. Obviously, depending upon the relative elevation of the pipe rack with respect to the derrick floor, i.e., below, level or above, the track systems could have a downward, horizontal, or upward attitude.

While several embodiments of the pipe handling apparatus of the invention have been shown and described, changes and alterations may be made of course without departing from the concept of the invention.

In this regard, it should be understood that pneumatic or other suitable power sources may be substituted in whole or in part for the hydraulic power devices employed in the specific embodiments disclosed.

Claims

1. In well drilling apparatus comprising a derrick and means associated with the derrick for raising and lowering drill pipe in relation to a drilling hole, apparatus for handling drill pipe which comprises:

a. a pipe rack adjacent the derrick for storing drill pipe in a substantially horizontal attitude;

b. a track extending from above the floor of the derrick to a location near the outboard end of drill pipe stored in the pipe rack;

c. a truck mounted on said track and movable along said track from above the floor of the derrick to the outboard end of drill pipe stored in the pipe rack;

d. releasable gripping means mounted on said truck for gripping drill pipe near its outboard end, said gripping means being pivotal about an axis transverse to the movement of said truck on said track and being disposed in relation to said track to permit drill pipe held by said gripping means to pass by said track as said gripping means pivots;

e. means located near the outboard end of pipe stored in the pipe rack for transferring drill pipe between said pipe rack and said gripping means; and

f. means for transferring the inboard end of drill pipe between the pipe rack and a location above the floor of the derrick where said inboard end of said drill pipe can be delivered to said means for raising and lowering drill pipe;

g. said gripping means pivoting in relation to said truck as said truck moves along said track and the inboard end of the drill pipe is raised or lowered in the derrick, between a position holding the drill pipe substantially horizontally near the outboard end of the track to a position holding the drill pipe substantially vertically when said truck is located over the floor of the derrick and the inboard end of drill pipe

2. Apparatus as defined in claim 1 wherein said gripping means comprises a frame pivotaly mounted on said truck, a pipe stop depending from said frame, and inboard of said stop a pipe latch depending from said frame.

3. Apparatus as defined in claim 2 wherein said latch comprises a plate depending from said frame and having a vertically disposed slot therein for accepting drill pipe, a pivot mounted on said plate, a locking arm mounted on said pivot, the pipe bearing surface of said arm in its closed position crossing the slot to confine pipe within said slot, means associated with the plate and the arm for biasing the arm to its closed position, a cam surface on the outside bottom surface of the arm for pivoting the arm away from its closed position and clearing the slot when pipe is moved forcibly into the slot, and means associated with said arm for receiving an applied force to pivot the arm and clear the slot for

4. Apparatus as defined in claim 1 wherein said track includes two parallel rails disposed horizontally from one another, the truck is movably mounted between said rails, and the gripping means pivots along a path which passes between said rails, said rails being sufficiently free of interconnection to permit drill pipe held in said gripping means to pass

5. Apparatus as defined in claim 1 wherein said track has associated with its end over the derrick floor a cam surface, and said gripping means has a cam surface mating therewith to rotate the gripping means into position

6. Apparatus as defined in claim 1 wherein a drive assembly is associated

7. Apparatus as defined in claim 1 wherein said means for transferring drill pipe between said pipe rack and said gripping means includes a hydraulic lift which moves the drill pipe along a vertical plane between engagement with the gripping means and a transfer position in the pipe

8. Apparatus as defined in claim 7 wherein said pipe rack includes pipe conveying means for moving drill pipe between said transfer position and a

9. Apparatus as defined in claim 1 wherein said means for transferring the inboard end of drill pipe includes a hydraulically actuated lifting assembly with a roller mounted thereon for accepting and supporting drill pipe near its inboard end, said assembly raising the inboard end of the drill pipe to a position over the floor of the derrick when drill pipe is being transferred to the derrick from the pipe rack, said assembly lowering the inboard end of drill pipe from the floor of the derrick to a position for return to said transfer position when drill pipe is being

10. Apparatus as defined in claim 1 wherein said means for transferring the inboard end of drill pipe comprises:

a. a second track extending from above the floor of the derrick to a location near the inboard end of drill pipe stored in the pipe rack; and

b. a second truck mounted on said second track and movable along said track and having a pipe supporting position thereon for transporting the inboard end of drill pipe between the pipe rack and a location above the floor of the derrick where said inboard end of said drill pipe can be delivered to said means for raising and lowering drill pipe; and

power operated means is associated with said trucks for moving the first truck along the first track and for moving the second truck along the

11. Apparatus as defined in claim 10 wherein said power operated means includes a first drive assembly connected to the first truck and a second drive assembly connected to the second truck, each of said drive

12. Apparatus as defined in claim 10 wherein elevating means is located near the end of the second track over the floor of the derrick for raising

13. Apparatus as defined in claim 12 wherein said elevating means comprises a hydraulic lift with a roller thereon for supporting the drill pipe near

14. Apparatus as defined in claim 10 wherein said pipe rack includes conveying means for transporting horizontally disposed drill pipe between a storage position in the pipe rack and a transfer position, and lifting means is disposed to transport drill pipe along a vertical plane between

15. Apparatus as defined in claim 14 wherein said lifting means includes a pluraltiy of hydraulically actuated lifts disposed along the length of drill pipe to be moved vertically, one of said lifts being located near the outboard end of the drill pipe for raising said drill pipe into engagement with said gripping means when transporting pipe to the derrick, and when removing pipe from the derrick for lowering said drill pipe from the gripping means for transport to the storage area of the pipe rack, another of said lifts being located near the inboard end of the drill pipe for lowering said drill pipe to a support position on the second truck when transporting pipe to the derrick, and when removing pipe from the derrick for raising said drill pipe from the support position on the second truck to a position for transport to the storage area of the pipe

16. Apparatus as defined in claim 10 wherein said second track curves from a position near the inboard end of drill pipe stored in the pipe rack to a position sufficiently above the floor of the derrick to permit drill pipe supported on the first and second trucks to be in a substantially vertical

17. Apparatus as defined in claim 16 wherein said second truck includes releasable gripping means pivotally mounted thereon for gripping drill

18. Apparatus as defined in claim 17 wherein said first truck and said second truck are connected by a link to keep the trucks substantially the

19. Apparatus as defined in claim 18 wherein a third truck is mounted on said first track outboard of said first truck, said first and third trucks are connected by a link to keep them substantially the same distance apart, and said power operated means drives said third truck, thereby also driving said first and second trucks through the links between adjacent

20. Apparatus as defined in claim 19 wherein said power operated means

21. Apparatus as defined in claim 17 wherein the gripping means of the first truck and the gripping means of the second truck are connected by an elongated member to link the trucks together and keep the trucks substantially the same distance apart during pipe handling operations.

22. Apparatus as defined in claim 21 wherein said pipe rack includes conveying means for transporting horizontally disposed drill pipe between a storage position in the pipe rack and a transfer position and lifting means is disposed to transport drill pipe along a vertical plane between the pipe rack and the gripping means of each the first truck and the second truck when the first and second trucks are in their outboard

23. Apparatus as defined in claim 22 wherein said lifting means includes a plurality of hydraulically actuated lifts disposed along the length of drill pipe to be moved vertically, said lifts being located for raising said drill pipe into engagement with the gripping means of the first and second trucks when transporting pipe to the derrick, and when removing pipe from the derrick for accepting drill pipe from the gripping means of the first and second trucks and lowering said drill pipe for transport to

24. Apparatus as defined in claim 21 wherein the gripping means of the first and second trucks each comprises a supporting structure pivotally mounted on each of said trucks, said elongated member extends between the supporting structure of each gripping means, said supporting structure of each gripping means has a pipe latch thereon, and the supporting structure of the gripping means of the first truck has a pipe stop connected therewith for stopping movement of drill pipe through the pipe latch when

25. Apparatus as defined in claim 24 wherein said pipe latch comprises a plate depending from said supporting structure and having a vertically disposed slot therein for accepting drill pipe, a pivot mounted on said plate above the slot, a locking arm mounted on said pivot, the pipe bearing surface of said arm in its closed position crossing the slot to confine pipe within said slot, means associated with the plate and the arm for biasing the arm to its closed position, a cam surface on the outside bottom surface of the arm for pivoting the arm away from its closed position and clearing the slot when pipe is moved forcibly into the slot, and means associated with said arm for receiving an applied force to pivot

26. In well drilling apparatus comprising a derrick and means associated with the derrick for raising and lowering drill pipe in relation to a drilling hole, apparatus for handling drill pipe which comprises:

a. a pipe rack adjacent the derrick for storing drill pipe in a substantially horizontal attitude, said pipe rack including conveying means for transporting horizontally disposed drill pipe between a storage position in the pipe rack and a transfer position, and hydraulic lifting means for moving at least the outboard end of horizontally disposed drill pipe in a vertical direction from said transfer position;

b. a first track extending from above the floor of the derrick to a location near the outboard end of drill pipe in said transfer position;

c. a first truck mounted on said first track and movable along said track from above the floor of the derrick to the outboard end of drill pipe in said transfer position, said truck having pipe gripping means comprising a frame pivotally mounted on said first truck about an axis transverse to the movement of said truck on said track, a pipe stop depending from said frame, and inboard of said pipe stop a pipe latch depending from said frame, said pipe latch cooperating with said lifting means to accept and hold drill pipe raised into the latch by said lifting means, said gripping means being disposed in relation to said first track to permit drill pipe held by said gripping means to pass by said track as said gripping means pivots;

d. a second track extending from above the floor of the derrick to a location near the inboard end of drill pipe positioned in said transfer position;

e. a second truck mounted on said second track and movable along said track and having a pipe supporting frame thereon, said second truck being disposed to support drill pipe near its inboard end as drill pipe is transferred between the pipe rack and the derrick;

f. a first drive assembly connected to said first truck and a second drive assembly connected to said second truck, each of said drive assemblies being operable independently of the other to move the trucks along their respective tracks and transport drill pipe between the pipe rack and the derrick; and

g. hydraulic elevating means located near the inboard end of the second track for raising the inboard end of the drill pipe off the second truck when transporting pipe to the derrick and for lowering drill pipe onto the second truck when removing pipe from the derrick, said elevating means including roller means to permit drill pipe to roll across the elevating

27. Apparatus as defined in claim 26 wherein said lifting means comprises a plurality of hydraulically actuated lifts disposed along the length of drill pipe in said transfer position, one of said lifts being located near the outboard end of the drill pipe for raising said drill pipe into engagement with said gripping means when transporting pipe to the derrick and when removing pipe from the derrick for removing drill pipe from the gripping means and lowering drill pipe to the transfer position for transport to the storage area of the pipe rack, another of said lifts being located near the inboard end of drill pipe in the transfer position for lowering drill pipe onto said pipe supporting frame on the second truck when transporting pipe to the derrick and when removing pipe from the derrick raising said drill pipe from said pipe supporting frame on the second truck to the transfer position for transport to the storage area of

28. In well drilling apparatus comprising a derrick and means associated with the derrick for raising and lowering drill pipe in relation to a drilling hole, apparatus for handling drill pipe which comprises:

a. a pipe rack adjacent the derrick for storing drill pipe in a substantially horizontal attitude, said pipe rack including conveying means for transporting horizontally disposed drill pipe between a storage position in the pipe rack and a transfer position, and hydraulic lifting means for moving horizontally disposed drill pipe in a vertical direction from said transfer position;

b. a first track extending from above the floor of the derrick to a location near the outboard end of drill pipe in said transfer position;

c. a first truck mounted on said first track and movable along said track from above the floor of the derrick to the outboard end of drill pipe in said transfer position, said truck having pipe gripping means pivotally mounted thereon to pivot about an axis transverse to the movement of said truck on said track;

d. a second track curving upwardly from a position near the inboard end of drill pipe in said transfer position to a location above the floor of the derrick;

e. a second truck mounted on said second track and movable along said track, said second truck having pipe gripping means pivotally mounted thereon to pivot about an axis transverse to the movement of said second truck on said second track;

f. the pipe gripping means of the first truck and of the second truck each comprising a supporting structure pivotally mounted on the truck and a pipe latch associated with the supporting structure, the supporting structure of the gripping means of the first truck having a pipe stop connected therewith for stopping movement of drill pipe through the pipe latch when the drill pipe is in a vertical attitude;

g. an elongated member connecting the supporting structures of the gripping means of the first and second trucks to maintain the trucks substantially the same distance apart during pipe handling operations;

h. the second track curving upwardly to a location sufficiently above the derrick floor to permit drill pipe supported in the first and second trucks to be in a substantially vertical position when the trucks are both located on their tracks over the derrick floor;

i. said lifting means including a plurality of hydraulically actuated lifts disposed along the length of drill pipe in said transfer position, said lifts being located for raising said drill pipe into engagement with the gripping means of the first and second trucks when transporting pipe to the derrick and when removing pipe from the derrick for accepting said drill pipe from the gripping means of the first and second trucks and lowering said drill pipe to said transfer position; and

j. means for driving the first truck along the first track, said second

29. In well drilling apparatus comprising a derrick and means associated with the derrick for raising and lowering drill pipe in relation to a drilling hole, apparatus for handling drill pipe which comprises:

a. a pipe rack adjacent the derrick for storing drill pipe in a substantially horizontal attitude, said pipe rack including pipe conveying means for moving horizontally disposed drill pipe between a storage position in the pipe rack and a transfer position;

b. a track extending from above the floor of the derrick to a location near the outboard end of drill pipe in said transfer position, said track including two parallel rails disposed horizontally from one another;

c. a truck mounted on said track between said rails and movable along said track from above the floor of the derrick to the outboard end of drill pipe in the transfer position;

d. releasable gripping means mounted on said truck for gripping drill pipe near its outboard end, said gripping means being pivotal about an axis transverse to the movement of said truck on said track and being disposed in relation to said track to permit drill pipe held by said gripping means to pass between said rails as said gripping means pivots, said rails being sufficiently free of interconnection to permit drill pipe held in said gripping means to pass between said rails;

e. a power operated drive assembly associated with said truck for driving said truck along said track;

f. means located near the outboard end of pipe stored in the pipe rack for transferring drill pipe between said pipe rack and said gripping means, said means including a hydraulic lift which moves the drill pipe along a vertical plane between engagement with the gripping means and the transfer position in the pipe rack; and

g. means for transferring the inboard end of drill pipe between the transfer position in the pipe rack and a location above the floor of the derrick where said inboard end of said drill pipe can be delivered to said means for raising and lowering drill pipe;

h. said gripping means pivoting in relation to said truck as said truck moves along said track and the inboard end of the drill pipe is raised or lowered in the derrick, between a position holding the drill pipe substantially horizontally near the outboard end of the track to a position holding the drill pipe substantially vertically when said truck is located over the floor of the derrick and the inboard end of drill pipe

30. Apparatus as defined in claim 29 wherein said gripping means comprises a frame pivotally mounted on said truck, a pipe stop depending from said frame, and inboard of said stop a pipe latch depending from said frame.

31. Apparatus as defined in claim 29 wherein said track has associated with its end over the derrick floor a cam surface, and said gripping means has a cam surface mating therewith to rotate the gripping means into position

32. Apparatus as defined in claim 29 wherein said means for transferring the inboard end of drill pipe includes a hydraulically actuated lifting assembly with a roller mounted thereon for accepting and supporting drill pipe near its inboard end, said assembly raising the inboard end of the drill pipe to a position over the floor of the derrick when drill pipe is being transferred to the derrick from the pipe rack, said assembly lowering the inboard end of drill pipe from the floor of the derrick to a position for return to said transfer position when drill pipe is being transferrred from the derrick to the pipe rack.