Patent Application
20060180315
1. Field of the Invention
Embodiments of the present invention generally relate to obtaining hydrocarbon fluid from a wellbore. More specifically, embodiments of the present invention relate to connecting tubulars and drilling the wellbore using tubulars.
2. Description of the Related Art
To obtain hydrocarbon fluid from the earth, a wellbore is formed in the earth. The wellbore is typically drilled using a drill string having a drill bit connected to its lower end. The drill string is rotated and lowered into the earth to form the wellbore.
After the wellbore is drilled to a first depth, the drill string is removed from the wellbore. To prevent collapse of the wellbore wall, casing is often used to line the wellbore. Lining the wellbore involves lowering the casing into the drilled-out wellbore and setting the casing therein.
Casing is usually provided by the manufacturer in sections of a predetermined length; however, the length of casing which is desired for use in lining a section of the wellbore is often longer than the section length. To obtain the desired length of casing for use in lining the wellbore section, casing sections are often connected to one another to form a casing string. Typical casing sections are connected to one another by threaded connections.
Threadedly connecting casing sections to one another involves rotating one casing section relative to the other casing section. A first casing section is lowered partially into the wellbore and gripped by a gripping mechanism such as a spider to prevent rotational movement of the first casing section. The spider is located on or in the rig floor of a drilling rig disposed over the wellbore. A second casing section is then gripped and rotated relative to the first casing section to form the casing string by connecting the upper end of the first casing section to the lower end of the second casing section. Additional casing sections may be threadedly connected to the casing string in the same manner to add to the length of the casing string.
Various tools are utilized to rotate casing sections to make up these threaded connections (or break out the threaded connections when removing casing sections from the casing string) and to rotate the drill string to form the wellbore. One such tool is a top drive, which includes a motor for providing rotational force to the casing or drill string (both hereinafter referred to as “tubular”). The top drive is connected to the drilling rig and moveable relative thereto.
The lower end of the top drive is usually operatively connected to an apparatus for gripping the tubular so that the top drive is capable of rotating the tubular. The gripping apparatus is rotatable by the top drive relative to the top drive and the drilling rig.
Recently, an alternative method of lining the wellbore is proposed which involves drilling the wellbore with the casing which is used to line the wellbore, termed “drilling with casing.” In this method, the casing is rotated and lowered into the earth to form the wellbore. Casing sections may be threadedly connected to one another to form a casing string of a desired length or disconnected from one another to reduce the length of the casing string in a casing makeup or breakout operation. Drilling with casing is advantageous because drilling the wellbore and lining the wellbore is accomplished in only one step, saving valuable rig time and resources.
Some have suggested using the gripping apparatus in a drilling with casing operation to grip the casing and using the top drive to rotate the casing when drilling the casing into the wellbore and when making up or breaking out threaded connections. Using the gripping apparatus and the top drive in a drilling with casing operation is particularly attractive if the gripping apparatus and the top drive are capable of fluid flow therethrough to allow the typical circulation of fluid through the wellbore while drilling. The circulation of fluid through the casing and the wellbore removes the cuttings from the wellbore, the cuttings resulting from the drilling into the earth to form the wellbore.
Regardless of whether the operation involves drilling with casing or typical drilling and subsequent casing of the wellbore, existing top drives are only capable of imparting a specific range of torque to the drill string or casing. Often, because of their limited torque-providing capability, the existing top drives fail to supply sufficient torque to the drill string and/or casing to adequately effect the tubular drilling, running, and makeup and breakout operations. High output torque from the top drive is especially desirable for drilling with casing operations, as existing casing connections require torque above the capabilities of most currently-installed top drives.
Therefore, it is desirable to provide additional torque capacity to a top drive system for use in rotating a tubular during running, drilling, and/or pipe handling operations. It is further desirable to provide this additional torque capacity for retrofitting to existing top drive systems.
In one embodiment, a top drive assembly comprises a top drive capable of providing a first torque to a tubular and a torque boosting mechanism operatively connected to the top drive, the torque boosting mechanism capable of providing a second, additional torque to the tubular.
In another embodiment, a method of manipulating a tubular comprises a top drive assembly comprising a top drive operatively connected to a torque altering mechanism; providing a first torque to the tubular using the top drive; and selectively adding a second torque to the tubular using the torque altering mechanism.
In yet another embodiment, a method of selectively providing rotational force to a tubular comprises providing a first torque source operatively connected to a second torque source; rotating the tubular at a first torque by activating the first torque source; and selectively rotating the tubular at a second torque by activating the second torque source.
In yet another embodiment, a method of selectively providing rotational force to a wellbore tubular comprises providing a torque supplying mechanism having an output shaft; coupling a torque altering mechanism to the output shaft and the wellbore tubular; rotating the output shaft at a first speed; and activating the torque altering mechanism to rotate the wellbore tubular at a second speed.
In yet another embodiment, a method of selectively providing rotational force to a wellbore tubular comprises providing a torque supplying mechanism having an output shaft; coupling a torque altering mechanism to the output shaft and the wellbore tubular; rotating the output shaft at a first torque; and activating the torque altering mechanism to rotate the wellbore tubular at a second torque.
So that the manner in which the above recited features of the present invention can be understood in detail, a more particular description of the invention, briefly summarized above, may be had by reference to embodiments, some of which are illustrated in the appended drawings. It is to be noted, however, that the appended drawings illustrate only typical embodiments of this invention and are therefore not to be considered limiting of its scope, for the invention may admit to other equally effective embodiments.
Embodiments of the present invention advantageously increase the torque capacity of a top drive system to permit increased torque impartation upon a tubular rotated by the top drive system. Embodiments of the present invention inexpensively and easily boost the torque capacity of an existing top drive system for tubular running, drilling, and/or handling operations.
The top drive 10 is capable of rotating a top drive output shaft 25 to ultimately provide rotational force for rotating the tubular 20. A gear/motor arrangement 28 is disposed around the top drive output shaft 25. The top drive output shaft 25 is capable of applying an increased torque to the output shaft 25, as opposed to the torque applied to the output shaft 25 which is output by the top drive 10, due to the additional torque capacity provided by operation of the gear arrangement 28 (when the gear arrangement 28 is activated to act upon the top drive output shaft 25).
The top drive output shaft 25 may be operatively connected to a gripping head, which is shown as an externally-gripping torque head 35 (grippingly engages an external surface of the tubular) in
An external surface of the tubular 20 is shown grippingly engaged by the torque head 35. In this position, the tubular 20 may be rotated by the top drive drilling system 5 and/or a fluid may sealingly flow through the entire top drive drilling system 5 and into and through the tubular 20, as desired. Alternatively, the output shaft 25 may be connected directly to the tubular 20.
The gear arrangement 28 is more clearly shown in
The first gear 45 is a portion of a first gear drive 55, while the optional second gear 50 is a portion of an optional second gear drive 60. A first motor 65 of the first gear drive 55 is capable of providing rotational force to rotate the first gear 45, and an optional second motor 70 is capable of providing rotational force to rotate the optional second gear 50. The first and second gear drives 55 and 60, through the rotational force of the first and second gears 45 and 50, cooperate to rotate the gear 40. (When the second gear drive 60 is not utilized as part of embodiments of the present invention, only the first drive 55 rotates the first gear 45 and only the first gear 45 rotates the gear 40.)
The first motor 65 rests on a first support 66 extending from the top drive track 5 and includes a rotor (not shown) extending through the first support 66 and through the first gear 45. Likewise, the second motor 70 is located on a second support 71 extending from the track 15 and includes a rotor (not shown) extending through the second support 71 and through the second gear 50. The first support 66 may be disposed on an opposite side of the shaft 25 from the second support 71 (and so may their associated gear drives 55 and 60). Other support arrangements are within the scope of embodiments of the present invention, for example if only one gear drive 55 is utilized to rotate the gear 40.
The first and second motors 65 and 70 are capable of rotating their respective rotors with respect to the first and second supports 66 and 71 to rotate the first and second gears 45 and 50, respectively, thereby adding power to the system. The first and second motors 65 and 70 may be electrically, mechanically, and/or fluid powered by any method known to those skilled in the art. Preferably, the first and second motors 65 and 70 are fluid-powered.
In operation, referring to
At any point during the pipe handling or drilling operation, if it is desired to apply additional torque to the tubular 20 (i.e., boost the amount of torque applied to the tubular 20), the first and second motors 65 and 70 are selectively activated to rotate the first and second gears 45 and 50. The teeth of the first and second gears 45 and 50 then cooperate with the teeth of the gear 40 to rotate the gear 40. The gear 40 applies the additional torque provided by the first and second gear drives 55 and 60 to the top drive output shaft 25. Therefore, when the gear arrangement 28 is activated, the amount of torque applied to the top drive output shaft 25 (and therefore the amount of torque applied to the tubular 20 via the torque head 35) is not limited to the amount of torque which the top drive 10 is capable of applying to the top drive output shaft 25 and tubular 20, but is instead equal to the sum of the amount of torque applied by the top drive 10 plus the amount of torque applied by the gear arrangement 28. The amount of torque applied by the gear arrangement 28 may be adjusted as desired before, during, or after the operation.
After applying the desired amount of torque to the tubular 20, the torque head 35 may be released from gripping engagement with the tubular 20. The torque head 35 may then be utilized to grippingly engage an additional tubular (not shown), and the top drive 10 and/or the gear arrangement 28 may again be activated to rotate the additional tubular using the desired amount of torque.
The difference between the first embodiment and the second embodiment is that the gear arrangement 28 of the first embodiment is replaced with a gear box 195 in the top drive drilling system 190 of the second embodiment, as shown in
As described above in relation to the gear arrangement 28 of the first embodiment, the primary function of the gear box 195 is to increase the torque capacity of the top drive 110. To accomplish this task, the gear box 195 is capable of rotating the gear output shaft 130 at a lower rate of speed (but higher torque) than the speed at which the top drive is capable of rotating the top drive output shaft 125, which is the input shaft to the gear box 195.
The gear box 195 preferably is planetary with rotating seals, where an input shaft drives a planet and a ring gear drives an output shaft. Furthermore, the gear box 195 is preferably shiftable to allow switching to different speeds, for example switching from a 1:2 or 2:1 speed or torque ratio to a different speed or torque ratio so that the gear option is 1:1. Although any type of gear box known to those skilled in the art is usable with the present invention, an exemplary gear box usable as part of the present invention is preferably planetary and co-axial with an input and output shaft to change speed and torque, as shown and described in U.S. Pat. No. 5,385,514 issued on Jan. 31, 1995, which is herein incorporated by reference in its entirety. The gear box used as part of the present invention preferably is shiftable such as the gear box shown and described in U.S. Pat. No. 6,354,165 issued on Mar. 12, 2002, which is also herein incorporated by reference in its entirety.
An advantage of utilizing the gear box 195 as the torque booster is that the gear box 195 may be set to provide a given ratio of additional torque to the gear output shaft 130 relative to the torque provided to the top drive output shaft 125, e.g., the gear box 195 may provide an input to output torque ratio of 1:2 to double the torque (thereby decreasing the speed of rotation of the tubular by ½). It is contemplated that the gear box may also be used to alter the speed of the gear output shaft 130 such that torque is decreased, e.g., the gear box 195 may provide an input to output torque ratio of 2:1 to reduce the torque by half. An additional advantage in using the gear box 195 is that there are no exposed rotating parts involved with the operation of the gear box 195 itself.
The operation of the top drive drilling system 190 is similar to the operation of the top drive drilling system 5. When it is desirable to add to the amount of torque supplied by the top drive 110 for rotating the tubular 120, the gear box 195 is selectively activated to increase the amount of torque applied to the gear output shaft 130, torque head 135, and tubular 120. The gear box 195 possesses a bore therethrough to allow drilling fluid and/or wireline to pass through the gear box 195 during the drilling, casing, and/or pipe handling operation.
The first and second embodiments described above include various forms of a top drive torque booster, including specifically the gear box 195 and the gear arrangement 28. Other types of torque boosters known to those skilled in the art are usable as part of the present invention, including but not limited to chain connections (rotationally connecting the gears by chains when the gears are separated from one another) or any other torque-transmitting couplings, as well as any other gear mechanisms known to those skilled in the art.
The ability to apply additional torque afforded by adding a torque booster, regardless of the type, to the top drive system is especially advantageous in retrofitting existing top drives, which often possess a limited torque capacity, with additional torque capabilities. Increasing the torquing ability of the top drive 10, 110 is particularly useful in casing running and casing drilling operations, where additional torque is sometimes required to rotate the casing or connect casing threads. The torque booster is capable of monitoring and controlling the amount of torque provided to the tubular gripped by the gripping head.
In an alternate embodiment, the top drive may be eliminated in any of the above-described embodiments, and the torque booster may be utilized as the only device for providing torque to the tubular. In a further alternate embodiment, the gripping head may be eliminated and replaced by another type of tubular gripping mechanism, such as an elevator. Yet a further alternate embodiment involves including a gear reducer instead of the torque booster if it is desired to selectively decrease the amount of torque applied by the top drive.
The torque booster is usable in a drilling with casing, casing lowering, casing make-up or break-out, tubular or drill pipe make-up or break-out, tubular or drill pipe lowering, or tubular or drill pipe drilling operation, or any other operation which requires rotating, lowering, and/or drilling a tubular body for placement of or while placing the tubular body into a wellbore within a formation. Directional terms stated herein, including “upper” and “lower,” for example, are merely indications of relative movements of objects and are not limiting.
Although increasing the capacity of torque applicable by the top drive is accomplished by the gear box described above, it is also within the scope of embodiments of the present invention to merely use the gear box to decrease the amount of torque which it is necessary to apply to the tubular using the top drive during a given operation (to allow the top drive to operate below its torque capacity), thereupon reducing wear and tear on the top drive unit. Additionally, the gear box may be utilized as a spinner to spin the tubular without adding torque to the top drive by operating in neutral or by adding a lesser amount of torque for a portion of the threading operation, and then the speed of rotation of and torque to the tubular may be changed at the thread-makeup point by shifting the speed (torque) which the gear box provides to the tubular at this point. For example, the gear box may be shifted to change from a high speed output, low torque to a low speed output, high torque.
In another embodiment, a method of selectively providing rotational force to a wellbore tubular comprises providing a torque supplying mechanism having an output shaft; coupling a torque altering mechanism to the output shaft and the wellbore tubular; rotating the output shaft at a first speed; and activating the torque altering mechanism to rotate the wellbore tubular at a second speed.
In another embodiment, a method of selectively providing rotational force to a wellbore tubular comprises providing a torque supplying mechanism having an output shaft; coupling a torque altering mechanism to the output shaft and the wellbore tubular; rotating the output shaft at a first torque; and activating the torque altering mechanism to rotate the wellbore tubular at a second torque.
In one or more of the embodiments disclosed herein, the first speed is higher than the second speed.
In one or more of the embodiments disclosed herein, the first speed is lower than the second speed.
In one or more of the embodiments disclosed herein, rotating the tubular connects the tubular to another tubular.
In one or more of the embodiments disclosed herein, the torque altering mechanism comprises a gear arrangement.
In one or more of the embodiments disclosed herein, the torque supplying mechanism comprises a top drive.
In one or more of the embodiments disclosed herein, the torque altering mechanism is coupled to the wellbore tubular using a gripping mechanism.
In one or more of the embodiments disclosed herein, the gripping mechanism is one of a gripping head or an internal gripping mechanism.
In one or more of the embodiments disclosed herein, the wellbore tubular is connected to an output shaft of the torque altering mechanism.
In one or more of the embodiments disclosed herein, the first torque is higher than the second torque.
In one or more of the embodiments disclosed herein, the first torque is lower than the second torque.
While the foregoing is directed to embodiments of the present invention, other and further embodiments of the invention may be devised without departing from the basic scope thereof, and the scope thereof is determined by the claims that follow.
This application claims benefit of co-pending U.S. Provisional Patent Application Ser. No. 60/644,661, filed on Jan. 18, 2005, which application is herein incorporated by reference in its entirety.
| Number | Date | Country | |
|---|---|---|---|
| 60644661 | Jan 2005 | US |
