1. Field
This disclosure relates generally to techniques for performing wellsite operations. More specifically, the present invention relates to techniques, such as blowout preventers (BOPs) and related devices, for controlling leaks at a wellsite.
2. Background of the Related Art
Oilfield operations are typically performed to locate and gather valuable downhole fluids. Oil rigs may be positioned at wellsites, and downhole tools, such as drilling tools, may be deployed into the ground to reach subsurface reservoirs. Once the downhole tools form a wellbore to reach a desired reservoir, casings may be cemented into place within the wellbore, and the wellbore completed to initiate production of fluids from the reservoir. Casing, pipes or other tubing may be positioned in the wellbore to enable the passage of subsurface fluids to the surface. During wellsite operations a blowout preventer (BOP) may be placed at a wellhead to control pressure from the wellbore.
Leakage of subsurface fluids may pose a threat if released from the wellbore. Equipment, such as a BOP, may be positioned about the wellbore to form a seal with and/or sever pipes therein to prevent leakage of fluid as it is brought to the surface. In some cases, the BOPs employ rams and/or ram blocks that seal and/or sever tubing from the wellbore. Some examples of ram BOPs and/or ram blocks are provided in U.S. patent application Ser. No. 12/838,701, U.S. Pat. Nos. 4,647,002, 6,173,770, 5,025,708, 7,051,989, 5,575,452, 6,374,925, 2008/0265188, 5,735,502, 5,897,094, 7,234,530 and 2009/0056132. Some BOPs have bonnets as described, for example, in U.S. Pat. Nos. 5,897,094 and 7,044,430.
Despite the development of techniques relating to rams and/or ram blocks, there remains a need to provide advanced blowout preventer techniques. The present invention is directed to fulfilling these needs in the art.
In at least one aspect, the disclosure relates to a ram assembly for a blowout preventer for receiving a tubular of a wellbore. The ram assembly has a ram block therein for engagement with the tubular, a ram shaft for selectively extending and retracting the ram block and a ram connector for operatively connecting the ram shaft to the ram block. The ram block has at least one block groove. The ram shaft has a ram head with at least one shaft groove. The ram connector has at least one shear connector correspondingly disposable in the block groove and the shaft groove whereby the ram shaft is releasably securable to the ram block.
The ram connector may be a rod receivable in the block groove and the shaft groove. Optionally, the ram connector may have an elliptical cross-section and/or a rectangular cross-section. The ram connector may have a handle so that an operator, a remotely operated vehicle and/or a replacement system may grip and remove the ram connector from the ram block and/or the ram shaft. The ram connector may also have a lock which may couple the ram connector to the ram block and/or the ram shaft. Optionally, the ram connector extends through the ram block, the ram head, and/or a space between the ram head and the ram block. To receive the ram connector, the block groove and the shaft groove may define a connection angle. Optionally, the shaft groove may be on a horizontal or vertical surface of the ram head. The ram block may have a receptacle for receiving the ram head of the ram shaft. The ram assembly may have a seal disposable about the ram block for sealing engagement with the tubular. The ram assembly may have a blade disposable about the ram block for severing engagement with the tubular. In another aspect, the disclosure relates to a blowout preventer for receiving a tubular of a wellbore. The blowout preventer has a body and at least one ram assembly. The body has a hole therethrough for receiving the tubular and at least one channel therethrough. Each ram assembly is positionable in a corresponding channel. The ram assembly may have a ram block for engagement with the tubular, a ram shaft for selectively extending and retracting the ram block, a ram connector for operatively connecting the ram shaft to the ram block and at least one actuator for selectively activating the ram assembly. The ram block has at least one block groove. The ram shaft has a ram head with at least one shaft groove. The ram connector includes at least one shear connector correspondingly disposable in the block groove and the shaft groove whereby the ram shaft is releasably securable to the ram block. The blowout preventer may further have a controller and/or a remote operated vehicle.
Finally, in yet another aspect, the disclosure relates to a method of assembling a ram assembly for a blowout preventer for receiving a tubular of a wellbore. The method involves providing a ram assembly having a ram block for engagement with the tubular, a ram shaft for selectively extending and retracting the ram block, a ram connector for operatively connecting the ram shaft to the ram block and a ram connector for operatively connecting the ram shaft to the ram block. The ram block has at least one block groove and a ram head with at least one shaft groove. The ram connector includes at least one shear connector. The method also involves releasably securing the ram shaft to the ram block by correspondingly disposing the shear connector in the block groove and the shaft groove.
The method may also involve disposing the ram head of the ram shaft in a receptacle of the ram block. The step of releasably securing may involve disposing the ram connector in a space between the ram shaft and the ram block, or through one of the ram shaft, the ram block or combinations thereof.
So that the above recited features and advantages of the present disclosure can be understood in detail, a more particular description of the techniques, briefly summarized above, may be had by reference to the embodiments thereof that are illustrated in the appended drawings. It is to be noted, however, that the appended drawings illustrate only typical embodiments of the disclosure and are, therefore, not to be considered limiting of its scope, for the techniques may relate to other equally effective embodiments. The figures are not necessarily to scale and certain features, and certain views of the figures may be shown exaggerated in scale or in schematic in the interest of clarity and conciseness.
The description that follows includes exemplary apparatuses, systems, methods, techniques, and instruction sequences that embody techniques of the present subject matter. However, it is understood that the described embodiments may be practiced without these specific details.
The techniques herein relate to devices, such as ram connectors, used with ram blocks of a blowout preventer. These techniques may be used to provide more efficient removal/installation of ram blocks, and/or to provide a robust connection of the ram blocks to the blowout preventer. These techniques may involve one or more of the following, among others: a robust connection between the ram shaft and the ram block, adaptability to wellsite equipment (e.g., various pipe diameters), enhanced interchangeability, performance under deflection and/or wellsite equipment failures, distribution and/or absorption of loads, reduced space requirements, enhanced manufacturing capabilities (e.g., wider tolerances), balanced pressures, and increased capacity (e.g., load, pressure, etc.)
The ram block assembly 102 may have a ram block 118, a ram shaft 120 and a ram connector 122 (shown schematically). The ram connector 122 may be configured to allow for the quick removal and installation of the ram block 118 from the ram shaft 120, as will be discussed in more detail below. A remotely operated vehicle (ROV) 136 may be deployed from the surface to access the ram block assembly 102 in the BOP 104 to complete the removal and/or installation process.
While the offshore wellsite 100 is depicted as a subsea operation, it will be appreciated that the wellsite 100 may be land or water based, and the ram block assembly 102 may be used in any wellsite environment. The pipe 108 may be any suitable tubular and/or conveyance for running tools into the wellbore 106 such as a drill string, a casing, a production tubing, a tool joint, a bottom hole assembly, a wireline, a coiled tubing, and the like.
A surface system 124 may be used to facilitate operations at the offshore wellsite 100. The surface system 124 may include a rig 126, a platform 128 (or vessel) and a surface controller 130. Further, there may be one or more subsea controllers 132. While the surface controller 130 is shown as part of the surface system 124 at a surface location, and the subsea controller 132 is shown as part of the subsea system 110 in a subsea location, it will be appreciated that one or more controllers 130, 132 may be located at various locations to control the surface and/or subsea systems.
To operate the ram block assembly 102 and/or other devices associated with the wellsite 100, the surface controller 130 and/or the subsea controller 132 may be placed in communication therewith. The surface controller 130, the subsea controller 132, and/or any devices at the wellsite 100 may communicate via one or more communication links 134. The communication links 134 may be any suitable communication system and/or device, such as hydraulic lines, pneumatic lines, wiring, fiber optics, telemetry, acoustics, wireless communication, any combination thereof, and the like. The ram block assembly 102, the BOP 104, and/or other devices at the wellsite 100 may be automatically, manually, and/or selectively operated via the controllers 130 and/or 132.
The BOP 104a of
The BOP 104a, as shown, has one ram block assembly 102 with blades 206 for severing the pipe 108, and one ram block assembly 102 with a seal 208 for sealing the hole 200 and/or the annulus around the pipe 108. Each of the ram block assemblies 102 may have the ram blocks 118, the ram shaft 120 and the ram connector 122. The ram shaft 120 may couple to an actuator 210 (shown schematically). The actuator 210 may be configured to move the ram shaft 120 and the ram blocks 118 between an operating position, as shown in
The ram block assembly 102 of
The connection system 328, as shown, may be any suitable device, or system for sealing and coupling the bonnet 320 to the BOP 104b, and thereby aligning the ram block 118 with the alignment channel 326. Although, the bonnet 320, is shown, as a hinged bonnet, it should be appreciated that any suitable bonnet or door may be used to allow access to the ram blocks 118, and/or the ram connector 122. When the bonnet 320 is open, the ram connector 122 may be accessed in order to remove and/or replace the ram block 118.
The ram block 118 may be configured to couple to the ram shaft 120 with the ram connector 122. The ram block 118 may be any suitable ram block for supporting the blade 206 and/or the seal 338, so long as the ram block 118 is configured to receive the ram connector 122. The ram shaft 120 may be configured to couple to the actuator 310 in order to move the ram block 118. The ram shaft 120 may be any suitable ram shaft for moving the ram block 118.
The ram connector 122 may be a removable shear connection configured to couple the ram shaft 120 to the ram block 118 (as will be discussed in more detail below). To uncouple the ram block 118 from the ram shaft 120, an operator, ROV 136 (
The ram connector 122 may allow for a robust connection between the ram block 118 and the ram shaft 120. The connection may not require the ram block 118 to be moved perpendicular to the ram shaft 120 in order to disconnect. This may allow a portion of the ram block 118 to be located within the bonnet 320 while the ram connector 122 is removed. This may allow the ram shaft 120 to be shorter than traditional ram shafts, thereby saving space and money. The ram connector 122 may have a number of configurations so long as the ram connector 122 is configured to be a removable shear connection between the ram block 118 and the ram shaft 120.
The shaft connector 444 may be any suitable device capable of forming a shear connection with the ram connector 122. As shown, the shaft connector 444 may be a shaped head 446 having one or more shaft grooves 448 for receiving a portion of the ram connector 122. As shown, the one or more shaft grooves 448 are two semi-circular grooves on a top 450 and a bottom 452 of the shaped head 446. The ram connector 122 may be configured to rest partially within the semi-circular grooves in a connected position, thereby preventing the ram shaft 120 from uncoupling from the ram block 118. Having one or more shaft grooves 448 extend along a length of the shaped head 446 may further prevent pivoting between the ram shaft 120 and the ram blocks 118 during operation. Although the shaft connector 444 is shown as having the two semi-circular grooves on the top 450 and the bottom 452 of the shaped head 446, any suitable design for creating a shear connection between the ram connector 122 and the ram shaft 120 may be used. For example, the one or more shaft grooves 448 may extend from the top 450 to the bottom 452 of the shaped head 446, the one or more shaft grooves 448 may be holes, apertures, square, hexagonal, polygonal, triangular, and the like.
The ram blocks 118 may have a tool receiving end 454 and a ram connector end 456. The tool receiving end 454 may be for receiving the blade 206, and/or the seal 208 (as shown in
The ram shaft receiving portion 460, as shown in
The ram connector 122 may be any suitable, removable device for forming a shear connection between the ram block 118 and the ram shaft 120. The ram connector 122 as shown, has one or more shear connectors 464 and a handle 466. The shear connector(s) 464, as shown, are two cylinders configured to pass through the apertures 458 and into a space formed by the one or more shaft grooves 448 and the one or more block grooves 462. Although the shear connectors 464 are shown as two cylinders, the shear connectors 464 may be any suitable shaped device for being received by the ram blocks 118 and the ram shaft 120. Further, there may be any suitable number of shear connectors 464.
The handle 466, as shown in
The ram connector 122 may lock to the ram block 118 and/or the ram shaft 120 using any suitable method. For example, a lock 467, such as a bolt, may couple to the ram block 118 through a handle aperture 468, as shown in
The ram block assemblies 102a,b may be the same as the ram block assembly 102 previously described herein. The ram block assemblies 102a,b of FIGS. 5A,5B have a shear connector 464a,b, one or more shaft grooves 448a,b and one or more block grooves 462a,b having elliptical and square cross-sections, respectively. Each of the shear connectors 464a,b of the ram connector 122 is located in corresponding space(s) 570a,b created by the one or more shaft grooves 448a,b of the ram shaft 120, and the one or more block grooves 462a,b of the ram block 118. The ram connector 122 forms the shear connection with an elliptical and square cross section, and the space(s) 570a,b formed by the one or more shaft grooves 448a,b and the one or more block grooves 462a,b are elliptical and square, respectively.
In the version of
In the version of
In the version of
The steps of the method may be performed in any order, and repeated as desired. It will be appreciated by those skilled in the art that the techniques disclosed herein can be implemented for automated/autonomous applications via software configured with algorithms to perform the desired functions. These aspects can be implemented by programming one or more suitable general-purpose computers having appropriate hardware. The programming may be accomplished through the use of one or more program storage devices readable by the processor(s) and encoding one or more programs of instructions executable by the computer for performing the operations described herein. The program storage device may take the form of, e.g., one or more floppy disks; a CD ROM or other optical disk; a read-only memory chip (ROM); and other forms of the kind well known in the art or subsequently developed. The program of instructions may be “object code,” i.e., in binary form that is executable more-or-less directly by the computer; in “source code” that requires compilation or interpretation before execution; or in some intermediate form such as partially compiled code. The precise forms of the program storage device and of the encoding of instructions are immaterial here. Aspects of the invention may also be configured to perform the described functions (via appropriate hardware/software) solely on site and/or remotely controlled via an extended communication (e.g., wireless, internet, satellite, etc.) network.
While the embodiments are described with reference to various implementations and exploitations, it will be understood that these embodiments are illustrative and that the scope of the inventive subject matter is not limited to them. Many variations, modifications, additions, and improvements are possible. For example, one or more BOPs with various combinations of one or more shear connections between the ram block and the ram shaft may be used.
Plural instances may be provided for components, operations or structures described herein as a single instance. In general, structures and functionality presented as separate components in the exemplary configurations may be implemented as a combined structure or component. Similarly, structures and functionality presented as a single component may be implemented as separate components. These and other variations, modifications, additions, and improvements may fall within the scope of the inventive subject matter.
Filing Document | Filing Date | Country | Kind | 371c Date |
---|---|---|---|---|
PCT/US11/51472 | 9/13/2011 | WO | 00 | 3/4/2013 |
Number | Date | Country | |
---|---|---|---|
61382770 | Sep 2010 | US |