Tubular handling apparatus and method

[0001] The present application claims the benefit of 35 U.S.C. 111(b) provisional application Serial No. 60/359,535 filed Feb. 25, 2002, and entitled Tubular Handling Apparatus and Method, hereby incorporated herein by reference.

[0002] Not Applicable.

[0003] 1. Field of the Invention

[0004] The present invention relates generally to handling well bore tubulars. More particularly, the present invention relates to a system for handling and storing the tubulars as they are inserted into and removed from a well bore.

[0005] 2. Description of the Related Art

[0006] Drilling an oil or gas well involves two main operations: drilling and tripping. To commence the drilling procedure, a drill string composed of drill pipe and terminating with a drill bit is positioned within a drilling rig. A rotating drive mechanism rotates the drill string to bore the drill bit into the ground. The components of the drill string, such as drill collars and drill pipe, are threaded for interconnection. Depending on what type of drive system is being used, the uppermost length of drill pipe in the drill string is connected to the drive mechanism. As the drill bit advances and the top of the drill string approaches the working platform or drill floor of the drilling rig, additional lengths of drill pipe must be added to the drill string in order to advance the drill string further into the ground. Pipe is added by temporarily supporting the top of the drill string using slips and disconnecting the drive mechanism from the top of the drill string. The rig's elevating system then lifts a new section of drill pipe into position and the new section of pipe is connected to the top of the drill string. The drive mechanism is then reconnected to the drill string, and drilling operations resume until it is again necessary to add more sections of drill pipe.

[0007] Tripping is a necessary but unproductive part of the overall drilling operation, and involves two basic procedures. The first procedure is extracting drill pipe from the well (referred to as pulling out of hole mode, or POH), and the second is replacing drill pipe in the well (running in hole mode, or RIH). Tripping may be necessary for several reasons, such as for replacement of worn drill bits, for recovery of damaged drill string components, or for installation of well casing.

[0008] In POH mode, the drive mechanism is removed temporarily, the drill string is connected to pipe elevators, and the drill string is pulled partially out of the hole as far as the hoisting mechanism and geometry of the drilling rig will permit. The slips then support the drill string so that the section or sections of the drill pipe exposed above the drill floor may be disconnected or broken out and moved away from the well. The elevators then reengage the top of the drill string so that more of the drill string may be pulled out of the hole. This process is repeated until the desired portion of the drill string has been extracted. The procedure for RIH mode is essentially the reverse of that for POH mode.

[0009] Whatever type of rig is being used, drilling operations require a convenient storage area for drill pipe that will be either added to or removed from the drill string during drilling or tripping. On many rigs, drill pipe is stored vertically, resting on the drill floor and held at the top in a rack known as a fingerboard. This system typically requires a derrickman working on a monkey board high up in the rig, to manipulate the top of the drill pipe as it is moved in and out of the fingerboard. Other rigs use a pipe tub, which is a sloping rack typically located adjacent to and extending below the drill floor. Drill ships and ocean-going drilling platforms often provide for vertical or near-vertical storage of drill pipe in a Texas deck located under the drill floor, with access being provided through a large opening in the drill floor.

[0010] When sections of drill pipe are being added during drilling or in RIH mode during tripping, the pipe must be transported into position from the pipe storage area. The opposite applies in POH mode during tripping, when pipe removed from the drill string must be transported away from the well and then to the storage area. With most if not all known drilling rigs, these pipe-handling operations cannot be conveniently performed using the rig's main hoist, because the main hoist typically is centered over the well hole, and cannot be moved laterally. The pipe has to be moved laterally using either manual effort or auxiliary machinery. In addition, drilling a well bore requires pipe joints of different size and different maximum tool-end upsets. The placement and sizing of the pipe handling devices must take into account the range of sizes of pipes and their maximum too-end upset so as to contact the pipe body only and not the pipe ends.

[0011] It can readily be seen that the efficiency and economy of a well-drilling operation will increase as the amount of time and effort required for handling drill pipe is decreased. Drill pipe is typically manufactured in standard-length joints. One common length for a pipe joint is 31 feet. Many known rigs handle stands made up of two joints (doubles, in industry parlance) or three joints (triples), and such rigs are typically thought to provide significant operational cost savings over rigs that can handle only single joints of pipe.

[0012] Multiple-joint rigs have significant disadvantages, however. To accommodate doubles and triples, they must have taller masts. For instance, if the rig is to handle triples that are 93 feet long, the hoist must be able to rise 100 feet or more above the drill floor and the mast has to be even higher than that. Because of the increased height, the mast will obviously be heavier and therefore more expensive than a shorter mast, even though the maximum hoisting loads that the mast must be designed for might be the same in either case. A taller mast's weight and cost will be even further increased by the need to design it for increased wind loads resulting from the mast's larger lateral profile. A larger mast also requires a larger base to support the higher structure. The larger the size of the base, or footprint, the greater the overall cost of the well.

[0013] Tall, heavy rigs also have particular drawbacks when used on ocean-going drill platforms or drill ships. Each floating platform or drill ship has its own particular total weight limit, made up of dead weight plus usable load capacity. Every extra pound of rig weight adds to the dead weight and reduces the usable load capacity correspondingly. Extra dead weight not only increases fuel costs for transportation, but also increases expenses for supply ships, which must make more frequent visits because the platform or drill ship has less available load capacity for storage of supplies. Moreover, ocean-going rigs generally need to be even taller than comparable land-based rigs. The additional height is needed compensate for vertical heave of up to 15 feet or more to keep the drill bit working at the bottom of the hole under an essentially constant vertical load when the platform or drill ship moves up or down due to wave action.

[0014] Another shortcoming of tall rigs is that the center of gravity of the rig, as well as that of the entire drilling platform, generally rises higher as the mast becomes taller. This is especially true for rigs that have heavy hoisting equipment mounted high in the mast. In stormy conditions, drilling and tripping operations can become impractical, unsafe, or both. This risk increases as the rig's center of gravity rises, such that a tall rig generally will have to be shut down to wait out bad weather sooner than a shorter rig in the same weather. Downtime due to weather conditions, known as waiting on weather time (or WOW time) in drilling parlance, is extremely expensive. Experience in drilling operations has been that WOW time averages as much as 10% of total rig deployment time. Because the total expense of operating an offshore rig is commonly in the range of $150,000 or more per day, it is readily apparent that the pipe-handling economies made possible by offshore rigs with tall masts can be offset significantly by a corresponding risk of increased WOW time.

[0015] Another disadvantage of high mast rigs involves the transportation of mobile rigs from site to site. Typically, portable rigs are loaded onto trucks and moved to different locations. The cost and difficulty of transportation of the rigs can increase as the size of the rig increases. Transporting rigs can also involve travel over narrow roads and bridges and travel in hazardous weather. Thus, large rigs can provide obstacles as to the conditions and locations in which they can be transported.

[0016] Additionally, traditional rigs require certain manual intervention in handling the drill pipes at various stages of the drilling process. The process of manually moving pipe or manually operating equipment used to lift and or rotate pipe can be tedious and dangerous. Humans are sometimes required to load pipe onto pipe racks, roll pipe across the racks, pull single pipes to the rig floor, screw the threaded connections together, and stand pipe in combinations of two or three joints into the fingers of the racking board of a conventional derrick.

[0017] For all the reasons outlined above, there is a need in the well-drilling industry for a drilling rig: (1) that via automation and other means, provides for a safer work environment than that of a conventional rig; (2) that delivers significant cost savings derived from transporting drill pipe to and from a pipe storage area automatically so as to eliminate or minimize the need for time-costing manual labor; (3) that is light and easily movable to facilitate rig moves; and (4) that can work on narrow well centers and have a very small footprint.

[0018] In one embodiment, the pipe handling system comprises a pipe magazine, a pipe conveyor system, and a pipe arm for use in automatically handling pipes in conjunction with a drill rig for drilling a well bore. Alternatively, the pipe handling system includes multiple pipe magazines, each with conveyor systems that transport the pipe from one pipe magazine to another until the pipe is delivered to the pipe arm.

[0019] In operation, the pipe handling system runs in two modes, RIH mode where pipe is delivered from the magazine and POH mode where pipe is delivered to the magazine.

[0020] In the RIH mode, the pipe magazine delivers joints of pipe to the pipe conveyor system. The pipe conveyor system receives the joint of pipe from the magazine and then delivers the joint of pipe to the pipe arm. Clamps on the pipe arm then clamp around the pipe joint and hold it as the pipe arm pivots from a horizontal position to a vertical position. The pipe arm then presents the pipe joint over the well hole center where elevators on the rig latch on to the pipe. Once the elevators latch on to the pipe, the clamps on the pipe arm open and the pipe arm pivots back to its horizontal position.

[0021] The POH mode executes the opposite process from the RIH mode. Once the pipe elevators latch on to a pipe joint and the connection is broken from the drill string, the clamps on the pipe arm clamp around the pipe. The elevators then unlatch, release the pipe, and are raised out of the way of the pipe arm. The pipe arm then pivots back down to the horizontal position to deliver the pipe to the pipe conveyor system. Kickers on the pipe arm push the pipe onto the pipe conveyor system. The pipe conveyor system then delivers the pipe to the pipe magazine for loading and storage.

[0022] The entire system is alternatively automated and sequenced via electronic sensors and signals that measure the location of pipe at specific intervals. The entire system is also alternatively integrated with software and a general-purpose computer to ensure the pipe is passed from one machine to the next as seamlessly as possible.

[0023] The embodiments thus provide a pipe handling system for a drilling rig that provides for a safer work environment than that of a conventional rig. The system also delivers significant cost savings derived from transporting drill pipe to and from a pipe storage area automatically so as to eliminate or minimize the need for time-costing manual labor. The pipe handling system is also light and easily movable to facilitate rig moves. Finally, the pipe handling system is part of a drilling rig that can work on narrow well centers and have a very small footprint.

[0024] Thus, the embodiments comprise a combination of features and advantages that enable them to overcome various shortcomings or problems associated with prior devices. The various characteristics described above, as well as other features, will be readily apparent to those skilled in the art upon reading the following detailed description of the embodiments and by referring to the accompanying drawings.

[0025] For a more detailed description of the embodiments, reference will now be made to the accompanying drawings, wherein:

[0026] FIG. 1 is a perspective view of the pipe handling system;

[0027] FIG. 2 is a top view of the pipe handling system;

[0028] FIG. 3 is a front elevation view of the pipe handling system;

[0029] FIG. 4 is a perspective view of the pipe handling system;

[0030] FIG. 5 is a schematic view of the pipe handling system showing pipe being unloaded from the pipe magazine;

[0031] FIG. 6 is a schematic view of the pipe handling system showing pipe being loaded to the pipe magazine;

[0032] FIG. 7 is a side elevation view of the pipe handling system showing the pipe arm delivering the pipe to the drilling rig;

[0033] FIG. 8 is a top view of a pipe handling system with multiple pipe magazines; and

[0034] FIG. 9 is a block diagram of the sensor and control system for controlling the pipe handling system with a general-purpose computer.

[0035] FIGS. 1-4 show a pipe handling system 10 comprising a pipe magazine 12, a pipe conveyor system 13, and a pipe arm 16. The pipe handling system 10 handles pipes 18 in conjunction with a drilling rig 20 for drilling a well bore. The pipe magazine 12 and the pipe conveyor system 13 are modular units that allow for easy assembly, disassembly, and transportation of the pipe handling system 10.

[0036] As shown in FIG. 1, the pipe magazine 12 includes multiple integral pipe racks 22 arranged horizontally and spaced along the length of and inside the magazine 12 for supporting multiple layers of pipes 18 horizontally. The racks 22 pivot on the longitudinal axis of the pipes 18 to gravitationally bias the pipes 18 to one side of the magazine 12 or the other. The racks 22 pivot depending on whether the pipes 18 are being unloaded from or loaded onto the racks 22. Hydraulic cylinders 23 control the position of the racks 22. Each rack 22 comprises vertically spaced horizontal supports or slats 26 (FIG. 3) for arrangement of the pipes 18. Hydraulic cylinders 27 control the slats 26 and selectively extend the individual slats 26 for loading and unloading the pipes 18.

[0037] The pipe conveyor system 13 comprises vertical conveyors 30 on one side of each magazine 12 (FIG. 4). The vertical conveyors 30 can be a chain, elevator, belt, or any other suitable conveyor type. The vertical conveyors 30 each have a shovel arm 32 facing the rack 22 for moving the pipe 18 along the vertical conveyors 30. A motor 33 drives a shaft 31 (FIG. 4), which drives the vertical conveyors 30. Each magazine 12 also has a first set of three horizontal magazine pipe conveyors 34 (FIG. 4). As best shown in FIG. 4, the first set of magazine horizontal pipe conveyors 34 begins at the vertical conveyors 30 and extends to a second set of three magazine horizontal pipe conveyors 36. The second set of magazine horizontal pipe conveyors 36 begins at the end of the first set of magazine horizontal pipe conveyors 34 and extends out of the side of the magazine 12 to the pipe conveyor 14. A motor 37 drives a shaft 35, which drives the first set of magazine horizontal pipe conveyors 34 (FIG. 4). The first and second set of magazine horizontal pipe conveyors 34, 36 have a shovel arm 39 on each conveyor for moving the pipe 18 along the conveyors 34, 36.

[0038] As shown in FIG. 3, the pipe conveyor 14 begins at the end of the second set of the magazine horizontal pipe conveyors 36. As part of the pipe conveyor system 13, the pipe conveyor 14 transfers the pipe 18 back and forth between the pipe magazine 12 and the pipe arm 16. The pipe conveyor 14 can be a chain and shovel (ledge) arrangement, a synthetic belt with deep ridges, a push-pull machine that pushes or pulls pipe across a smooth surface, or any other suitable mechanism for moving pipe.

[0039] The pipe arm 16 is a large trussed or beam arm that pivots about a pivot point 42 (FIG. 2) located near the base of the drilling substructure 44 that supports the rig floor 46 of the rig (not shown). The arm 16 pivots from a horizontal position to a vertical position. At the horizontal position the arm 16 is loaded with pipe 18 from the pipe conveyor 14. At the vertical position, the arm 16 delivers pipe 18 to a staging position offset from the centerline of the hole. When the support arm 16 is required to deliver or receive a joint of pipe 18 from the well center, an articulating platform 48 that supports the pipe 18, pushes or pulls the pipe 18 from the staged position to wellbore centerline. A single hydraulic cylinder (not shown) located some distance from the pivot point 42 is used to pivot the arm 16 from the horizontal position to the vertical position. Clamps 50 hold the pipe 18 firmly against the back of the articulating platform 48. The clamps 50 do not grip the pipe 18, but only exert enough pressure to prevent the pipe 18 from moving. The articulating platform 48, attached to the pipe arm 16, includes a set of parallel arms with hydraulic cylinders (not shown) that are used to present the pipe 18 over the well center. This articulating distance can be adjusted to automatically align the pipe 18 center with the well hole center for a range of different pipe sizes. A lipped pipe stop (not shown), which is part of the articulating platform 48, can telescope up and down when the arm 16 is vertical. The pipe stop provides flexibility on: (1) how and where the pipe 18 is presented over the hole; (2) the ability to clear the pipe 18 from the pipe stop when offloading toward the magazine 12; and (3) the ability to engage pipe 18 in the elevators (not shown) without moving the drive mechanism (not shown). Steel rollers (not shown), driven only if necessary, are used to clear the pipe 18 from the pipe stop to offload towards the pipe conveyor 14, or to load pipe 18 to the pipe stop prior to lifting the pipe 18. Kickers (not shown), integral to the arm 16, are used to push the pipe 18 either toward the pipe conveyor 14 or toward a bottom hole assembly (BHA) module (not shown) on the opposite side of the arm 16 than the magazine 12.

[0040] In operation, the pipe handling system 10 runs in two modes, RIH mode where pipe 18 is delivered from the magazine 12 and RIH mode where pipe 18 is delivered to the magazine 12.

[0041] As shown schematically in FIG. 5, in RIH mode, the pipe magazine 12 delivers joints of pipe 18 to the pipe arm 16 using the pipe conveyor system 13. The rack hydraulic pistons begin the process by tilting the racks 22 toward the vertical conveyors 30. The slat hydraulic cylinders then selectively extend a slat 26 to place a pipe 18 in line with the shovel arms 32 of the vertical conveyors 30. The shovel arms 32 of the vertical conveyors then move the pipe 18 up where the pipe 18 is transferred to the first set of magazine horizontal conveyors 34. The pipe 18 then travels across the first set of magazine horizontal conveyors 34 and is transferred to the second set of magazine horizontal conveyors 36. The second set of magazine horizontal conveyors 36 then carry the pipe 18 out of the magazine 12 and onto the pipe conveyor 14. The pipe conveyor 14 finally carries the pipe 18 to the pipe arm 16. The clamps 50 on the pipe arm 16 clamp around the pipe joint 18 and hold it against the articulating platform 48 as the pipe arm 16 pivots from the horizontal position A as shown in FIG. 5 to the vertical position B as shown in FIG. 7. Once in position and the drillstring is ready to receive the pipe 18, the articulating platform 48 presents the pipe joint 18 over the well hole center. Elevators on the rig then latch on to the pipe 18 and lift it up. After sensors confirm that the pipe 18 has been lifted off and cleared the pipe stop, the clamps 50 open and the articulating platform 48 retracts. The pipe arm 16 then pivots back to its horizontal position B to await the loading of another pipe 18. The connection is then made between the pipe 18 and the rest of the drill string in a conventional manner and drilling or tripping is commenced. The process is repeated with the magazine 12 emptying one slat 26 at a time until no more pipes 18 need to be inserted into the well bore.

[0042] As shown schematically in FIG. 6, in POH mode, the opposite process from the RIH mode is executed. The rack hydraulic pistons 23 tilt the racks 22 away from the vertical conveyors 30. At the rig, the pipe elevators latch on to a pipe joint 18 and the connection is broken from the drill string in a conventional manner. The articulating platform 48 then extends from the pipe arm 16 and the clamps 50 clamp around the pipe 18. After sensors (not shown) sense that the articulating platform 48 and the pipe stop have engaged the pipe 18, the elevators unlatch, release the pipe 18, and are raised out of the way of the pipe arm 16. The articulating platform 48 then retracts and the pipe arm 16 pivots from position B shown in FIG. 7 back down to the horizontal position A to deliver the pipe 18 to the pipe conveyor 14. Kickers (not shown) on the pipe arm 16 then push the pipe 18 onto the pipe conveyor 14. The pipe conveyor 14 then delivers the pipe to the second set of horizontal conveyors 36 on the pipe magazine 12. The pipe 18 travels on the second set of horizontal conveyors 36, back into the magazine 12, and onto the first set of horizontal conveyors 34. The pipe 18 then travels across the first set of horizontal conveyors 34 until they reach the vertical conveyors 30. The magazine vertical conveyors 30 then lower the pipe 18 to the selected extended slat 26. When the pipe 18 engages the extended slat 26, it rolls to the end of the slat due to the tilt of the rack 22. In this manner, each slat 26 of the rack 22 is filled until the magazine 12 is full or until no more pipe joints 18 need to be removed from the bore hole.

[0043] Alternatively, the entire pipe handling system 10 is automated and sequenced using electronic sensors 100 and a general-purpose computer 102 as shown in FIG. 9. The sensors measure the location of the pipe 18 at specific intervals. The sensors 100 and the general-purpose computer 102 are used to load pipe 18 to and from the correct slat 26 in the magazine 12. There is also an assortment of sensors 100 on the pipe arm 16 to control the mechanisms that hold the pipe 18 to the arm 16, and release the pipe 18 at the correct time. The general-purpose computer 102 uses software to gather information from the sensors 100 and activate controllers 104 throughout the entire pipe handling system 10. The controllers 104 control various operations throughout the pipe handling system 10 to handle the pipes 18 such as operating the pipe arm 16, the conveyor system 13, the pipe racks 22, and the pipe slats 26.

[0044] As shown in FIG. 8, in another alternative, more than one pipe magazine 12 can be used in the pipe handling system 10. The additional pipe magazines 12 are spaced lengthwise so that the second set of horizontal conveyors 36 of the additional magazines 12 extend into the next magazine 12 closer to the pipe conveyor 14 and pipe arm 16. The operation is the same except the pipe joints 18 from the additional magazines 12 are transferred from pipe magazine 12 to pipe magazine 12 across the first set of horizontal conveyors 34 and the second set of horizontal conveyors 36 of the next magazine 12 closest to the pipe conveyor 14. The pipe joints 18 travel across the sets of horizontal conveyors 34, 36 until they reach the pipe conveyor 14 and the process of loading the pipe into the drillstring is carried out for the RIH mode. In the POH mode, the process is reversed and when one of the magazines 12 is filled, the pipe joints 18 are transferred across the sets of horizontal conveyors 34, 36 to the next magazine 12 and loaded as described above. The additional magazines 12 can also be operated independently. One magazine 22 can thus operate normally as described above while another magazine is loaded or unloaded to or from a forklift. In addition, pipe may be unloaded from or loaded to any of the pipe magazines 12 in any order.

[0045] The embodiments thus provide a pipe handling system for a drilling rig that, via automation and other means, provides for a safer work environment than that of a conventional rig. The system also delivers significant cost savings derived from transporting drill pipe to and from a pipe storage area automatically so as to minimize the need for time-costing manual labor. The pipe handling system is also light and easily movable to facilitate rig moves. The pipe handling system 10 is also capable of handling pipe joints of different size and different maximum tool-end upsets to contact the pipe 18 body only and not the pipe 18 ends. Finally, the pipe handling system is part of a drilling rig that can work on narrow well centers and have a very small footprint.

[0046] While embodiments have been shown and described, modifications can be made by one skilled in the art without departing from the spirit or teaching of this invention. The embodiments described are exemplary only and are not limiting. Many variations and modifications of the system and apparatus are possible and are within the scope of the invention. Accordingly, the scope of protection is not limited to the embodiments described, but is only limited by the claims that follow, the scope of which includes all equivalents of the subject matter of the claims.