Patent Application
20140298735
1. Field of the Invention
The present invention is directed to an apparatus for and a method of folding a mast or derrick. In particular, the present invention is directed to a folding mast or derrick that may be efficiently assembled and then disassembled and readily transported from one well site to another.
2. Related Art
Well drilling rigs in oil and gas operations are utilized to drill for reserves. Many times drilling does not result in a productive well and it has been estimated that over two million bore holes have been dug worldwide.
Masts or derricks are well known for use in oil and gas and other drilling operations. The mast or derrick may be mounted on a fixed platform or on a jackup platform above ground level over a well bore. A mast often extends up to two hundred feet above a drill floor and is often composed of structural steel framework which supports a crown assembly. A mast or derrick of a drilling rig supports a vertically moving block and tackle in order to raise and lower a series of drill pipes which support a drill bit.
One type of known portable derrick structure is disclosed in Kennard, Jr. (U.S. Pat. No. 4,651,884) which is mounted on a vehicle. The derrick is movable between horizontal and vertical positions.
One well known type of drilling structure includes a pair of sides with a back face joining the sides and an open front or V-door face. A mast is, accordingly, typically braced or cross braced on three sides with an open front face to receive and remove pipe sections and other equipment.
The mast or derrick itself may be composed of a lower or bottom mast section assembly connected to a drill floor and one or more upper mast section assemblies connected thereto on top of the lower mast section. In some configurations, the lower or bottom mast section is wider than the other mast sections.
As drilling is conducted, the drill bit becomes dull or broken and the whole drill string has to be taken out of the hole and the bit repaired or replaced. In addition, in some applications, casing, consisting of thick-walled pipes, are screwed together and lowered into the well.
From time to time, once a drilling project has been completed, it is required to move the drilling rig from one location to another location. In one known process, the entire drilling rig is disassembled piece by piece, then transported to the next location, and then reassembled piece by piece. This process is both labor intensive and time consuming.
As a technological advance on the complete disassembly and reassembly of the mast or derrick, a folding gin pole or A-pole arrangement was developed. The entire mast could be moved from vertical to horizontal position by a wire line extending from the crown assembly to a gin pole or A-pole at the base of the rig. Once in the horizontal position on the ground, the mast could thereafter be disassembled.
In many applications, the mast sections are transported by trailer. Disassembly of the mast sections is normally required due to roadway limits such as height and width.
It would be desirable to fit the various masts sections on to trailers for highway transportation with a minimum of disassembly.
Additionally, it would be advantageous for the mast sections to be able to meet roadway requirements for size of load. For example, certain highway regulations limit the width of the load to 12 or 14 feet. Accordingly, it would be advantageous to provide a mast or derrick wherein the mast sections may be reduced in size for transportation to a width acceptable for roadway requirements.
It would also be advantageous to provide a mast or derrick having sections that may be moved between an open, in-use position and a folded position for storage and transportation.
It would also be advantageous to provide a mast or derrick having sections that may be locked in either an open, in-use position or a folded position for storage and transportation.
It would also be advantageous to provide a mast or derrick that may be moved between an open in-use position and a folded position utilizing hydraulic cylinders.
It would also be advantageous to provide a mast or derrick wherein the required disassembly and subsequent re-assembly is reduced.
It would also be advantageous to provide a method of folding a mast wherein the block and tackle may be secured to a mast section during transportation and accordingly, disassembly is not required.
Assignee's prior patent (Brittain et al. U.S. Pat. No. 6,594,960) shows an example of articulating a back face of a mast or derrick using a crane and a forklift.
It would also be advantageous to provide a method of moving a mast or derrick between an open, in-use position and a folded position utilizing existing hydraulic systems on the drilling rig at the well site.
The present invention is directed to a folding mast and a method of folding and unfolding a mast.
The mast apparatus of the present invention includes a lower mast assembly and one or more upper mast assemblies mounted thereon. The lower mast assembly includes a pair of opposed sides with a back face joining the two opposed sides together. The lower mast assembly may be moved between a folded, closed, transportation position and an unfolded, open, use position.
At least one spreader beam assembly extends across the back face and connects the back legs of the pair of opposed sides.
Each spreader beam assembly includes a pair of inner members and a pair of outer channel members. Each inner member is pivotally connected to an outer channel member at a pivot shaft. When each spreader beam assembly is in the open, use position, the inner member is aligned with the outer channel member.
A pair of telescoping braces are provided for each spreader beam assembly. Each telescoping brace extends between its respective spreader beam assembly and one of the back legs.
A pair of mast folding cylinders are utilized and actuated to move the opposed sides between the open, use position and the closed, transportation position. The mast folding cylinders are each connected to the existing hydraulic system of the mast apparatus.
The embodiments discussed herein are merely illustrative of specific manners in which to make and use the invention and are not to be interpreted as limiting the scope of the instant invention.
While the invention has been described with a certain degree of particularity, it is to be noted that many modifications may be made in the details of the invention's construction and the arrangement of its components without departing from the spirit and scope of this disclosure. It is understood that the invention is not limited to the embodiments set forth herein for purposes of exemplification.
Referring to the drawings in detail,
At the base of the lower mast section 12 is a drill floor 40, below which is a substructure 42 supported by a sub base 44 on ground 46.
The mast apparatus 10 includes a pair of opposed sides with the left side 62 visible in
The mast apparatus 10 includes a back face joining the sides 62 and 64 (See
The back face includes a pair of stationery guide tracks 24 and 26 which are used as guides for a traveling block (not shown).
At least one spreader beam assembly 30 extends across the back face and connects the back legs of the pair of the opposed sides 62 and 64. As seen in
With continuing reference to
The outer channel member 34 is substantially C-shaped and is received over a portion of the inner member 32. Conversely, when each spreader beam assembly 30 is in the closed, transportation position as shown in
In the open use position, the closed transportation position or any position in between the pair of guide tracks 24 and 26 remain stationery.
A pair of telescoping braces 50 and 52 are provided for each spreader beam assembly 30. Each telescoping brace extends between its respective spreader beam assembly 30 and one of the back legs 20 or 22. In the present embodiment, the telescoping braces 50 and 52 include a pair of cylindrical tubes having an inner tube within an outer tube. In the open, use position shown in
A pair of mast folding cylinders 70 and 72 are utilized and actuated to move the opposed sides 62 and 64 from the open, use position to the closed, transportation position. The mast folding cylinders 70 and 72 are each connected to the existing hydraulic system (not shown) of the mast apparatus. When the pair of mast folding cylinders 70 and 72 are actuated, the length of the cylinders 70 and 72 is reduced and the pair of opposed sides are brought toward each other to the closed, transportation position as seen in
The pair of mast folding cylinders 70 and 72 are also utilized and actuated to unfold the mast apparatus 10 to move the opposed sides 62 and 64 from the closed, transportation position to the open, use position. When the mast folding cylinders 70 and 72 are actuated, the length of the cylinders 70 and 72 is extended and the pair of sides 60 and 64 are moved away from each other to the open, use position as seen in
A series of optional folding braces 80 and 82 may be observed from
In order to install and assemble the mast apparatus 10 at a new site,
As best seen in
As best seen in
As best seen in
In order to disassemble the mast apparatus for transportation to a new location, the reverse procedure is employed.
It will be appreciated that use of the present invention minimizes requirements of cranes and other lifting equipment.
Whereas, the present invention has been described in relation to the drawings attached hereto, it should be understood that other and further modifications, apart from those shown or suggested herein, may be made within the spirit and scope of this invention.
