Wellhead Protector

Abstract

A wellhead protector for inhibiting damage to a wellhead of an oil or gas well. The protector includes a skid having a first runner with a first end and a second end, a second runner with a first end and a second end, with the second runner spaced a distance from the first runner, and a first cross member connected between the first runner and the second runner. A cover is positioned above said skid, with the cover having a closable opening. Rollers are connected to the cover and in contact with said skid so the skid is movable relative to the cover.

Description

CROSS REFERENCE TO RELATED APPLICATIONS

Not applicable.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

Not applicable.

BACKGROUND OF THE INVENTION

1. Field of the Invention.

The present invention relates to the oil and gas industry. More specifically, the present invention is device for protecting a wellhead from damaged caused by falling objects and contact with vehicles or heavy equipment.

2. Description of the Related Art.

A wellhead is the component at the surface of an oil or gas well that provides the structural and pressure-containing interface for the drilling and production equipment. The primary purpose of a wellhead is to provide the suspension point and pressure seals for the casing strings that run from the bottom of the hole sections to the surface pressure control equipment. Once the well has been drilled, it is completed to provide an interface with the reservoir rock and a tubular conduit for the well fluids. The surface pressure control is provided by additional equipment installed on top of the wellhead that includes isolation valves and choke equipment to control the flow of well fluids during production.

Wellheads are typically welded onto the first string of casing, which has been cemented in place during drilling operations, to form an integral structure of the well. Damage to the wellhead also has a potential to damage the string to which it is attached and or the cement lining in the well. Not only would such damage be itself expensive to repair, but the lost value of production during while repairs are made could be as significant, if not more significant, than the cost of the repairs to the wellhead and attached equipment.

BRIEF SUMMARY OF THE INVENTION

The present invention is a protector for inhibiting damage to a wellhead of an oil or gas well. The invention includes a skid having a first runner with a first end and a second end, a second runner with a first end and a second end, with the second runner spaced a distance from the first runner, and a first cross member connected between the first runner and the second runner. A cover is positioned above said skid, with the cover having a closable opening. Rollers are connected to the cover and in contact with said skid so the skid is movable relative to the cover.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a perspective view of a first embodiment of the invention.

FIG. 2 is a partial view of the invention described with reference to FIG. 1

FIG. 3 is perspective view of the embodiment shown in FIG. 1 with the cover surrounding a wellhead.

FIG. 4 is a perspective view of a second embodiment of the invention.

DETAILED DESCRIPTION

FIG. 1 shows an embodiment 20 of the invention in use with a wellhead W protruding from a ground surface G. As used herein, “wellhead” includes any additional equipment attached to the wellhead for purposes of exploration or completion. The embodiment 20 comprises a skid 22 having a first end 24 and a second end 26, and a cover 28 movable on and relative to the skid 22 generally between the first end 24 and the second end 26.

The skid 22 comprises a first runner 30 and a second runner 32 parallel to and spaced a distance D from the first runner 30. Each runner 30, 32 has an intermediate section 34 between front end sections 36 and rear end sections 37 that are angled relative to the intermediate section 34. Because the intermediate sections 34 are in contact with the ground surface G, the front end sections 36 and rear end sections 37 are angled upward from the ground surface G. In this embodiment, the runners 30, 32 are formed from lengths of cylindrical metal drill pipes. However, it is anticipated that the cross-sectional shapes of the runners 30, 32 could vary.

The skid 22 further comprises a first cross member 38 removably connected (e.g., pinned, bolted or welded) to the first and second runners 30, 32 at a first pair of attachment positions 40 with pins 42. The pins 42 extend through flanges 44, which are welded to the first cross member 38, and into the runners 30, 32. Wheel stops 46, are connected to the runners 30, 32 proximal to each of the first pair of attachment positions 44. A hook 47 is connected to the outside of each runner 30, 32. In this embodiment, the wheel stops 46 are L-beam pieces welded to the runners 30, 32 but various shapes and connections of the wheel stops are anticipated.

In this embodiment 20, a second cross member 48 may be connected (e.g., pinned, bolted or welded) to the first and second runners 30, 32 at a second pair of attachment positions 50 proximal to the midpoints of the intermediate sections 34. A third cross member 52 may be connected to the first and second runners 30, 32 at a third pair of attachment positions 54 between the second pair of attachment points 50 and the second end 26 of the skid 22. Wheel stops 46 are also connected to the runners 30, 32 proximal to each of the third pair of attachment positions 54. A fourth cross member 56 is connected to the rear distal ends of the first and second runners 30, 32 at the second end 26 of the skid 22. The fourth cross member 56 is longer than the distance D and extends slightly past the runners 30, 32. In this embodiment, each of the first, second, third, and fourth cross members 38, 48, 52, 56 are formed of cylindrical metal drill pipe. However, it is anticipated that the cross-members 38, 48, 52, 56 may have various cross-sectional shapes.

In this embodiment, the skid 22 further comprises first and second planar horizontal track surfaces 57 and first and second planar vertical track 58. The track surfaces 57, 58 may be formed, by example, by welding L-beams 59 to the intermediate sections of the first and second runners 30, 32.

For convenience, the portion of the skid 22 between the second cross member 48 and the first end 24 may be referred to as the forward portion. The portion of the skid 22 between the second cross member 48 and the second end 26 may be referred to as the rear portion. In FIG. 1, for example, the wellhead W extends up from the ground surface G through the forward portion of the skid 22.

Still referring to FIG. 1, the cover 28 is generally frustrum-shaped and includes a frame 60 that forms a frontal wall 29, a left sidewall 31, a right sidewall 33, and a rear wall 35, and defines a space S, a square bottom opening 62 facing the ground surface G and adjacent to the space S, a rectangular front opening 64 adjacent to the space S and generally facing the first end 24 of the skid 22, and a square top opening 66. The cover 28 includes a cap made of two steel cap pieces 70 connected to the frame 60 on opposing sides of, and proximal to, the top opening 66 with hinges (not shown). A door 72 is connected to the frame 60 proximal to and covering the front opening 64. The door 72 has a frame 71 and a twelve-gauge mesh 73.

FIG. 2 shows a portion of the cover 28 in greater detail, looking into the front opening 64 toward the space S. The frame 60 is comprised by a number of steel members 74 welded together in the shape of a frustrum. Hooks 75 are welded to the frame 60 at the bottom of the rear wall 35 proximal to each of the rollers 84 and the bottom opening 62. A first pair of chains 77 are connected (e.g., welded) to the skid 22 near each of the third pair of attachment positions 54. Each chain 77 can be looped around one of the hooks 75. A second pair of chains 79 are connected to the frame 60 at the bottom of each sidewall 31, 33 proximal to the bottom opening 62. The distal ends of each of the second pair of chains 79 are connected to the steal members 74 forming the bottom end of each sidewall 31, 33 such that the chains 79 are stretched along the steal members 74. A third set of anchor chains 81 are welded to the inside of each of the runners 30, 32 at a position near each of the first pair of attachment positions 40 and a position near each of the second pair of attachment positions.

A number of panels 76 are connected to the frame 60. Each panel 76 is formed by connecting flat bar steel pieces 78 to form an opening, and then welding steel mesh 80 into or over the opening. While this embodiment contemplates the panels 76 being twelve-gauge steel mesh, alternative embodiments may incorporate completely solid panels or other gauges of mesh.

The cover 28 includes rollers 84 connected to the frame 60 with roller mounts 86. Each roller mount 86 is formed by connecting steel members 88 to the frame 60 proximal to the bottom opening 62 where each sidewall 31, 33 meet the rear wall 35. Axle brackets 90 are connected to the steel members 88 to support an axle 92 around which the roller 84 rotates.

Still referring to FIG. 2, a guide wheel 94 is connected to the frame 60 proximal to each roller 84. Each guide wheel 94 rotates around an axle (not shown) connected to a steel guide wheel connection member 96. The guide wheel connection member 96 is connected (e.g., welded) to the frame 60. In this embodiment, the guide wheels 94 are positioned outside of the skid 22 and proximal to the first and second vertical track surfaces 58 of L-beams 59, although alternative embodiments contemplate the guide wheels 94 positioned between the first and second runners 30, 32, although in such embodiments there must be a minimal number of cross members, which would otherwise obstruct movement of the cover 28 between the first and second ends 24, 26 of the skid 22.

Use of the embodiment 20 is initially described with reference to FIG. 1-2, in which the cover 28 is in a position proximal to the second end 26 of the skid 22. As shown in FIG. 2, the first pair of chains 77 is connected to the hooks 75, which inhibits inadvertent movement of the cover 28 relative to the skid 22.

After being moved to the worksite, the first cross member 38 is removed from the skid 22 to create an area A (see FIG. 3) bounded by the first runner 30, the second runner 32, and the middle cross member 48. The skid 22 is thereafter maneuvered, either manually or with the help equipment, so the area A surrounds the wellhead W and the front opening 64 is aligned with the wellhead W. For example, the embodiment 20 may be chained to a truck using hooks 47 and then dragged into a proper position. The angled ends 36 of the skid 22 facilitate movement by inhibiting the skid 22 from catching on rocks, objects, crevices, uneven terrain, and the like in the work area. The length of the fourth cross member 56 provides “handles” to facilitate manual movement of the skid 22 as necessary or desired. The first cross member 38 may thereafter be connected to the first and second runners 30, 32 to close off the area A.

The cover 28 is movable from the position shown in FIG. 1 to a position shown in FIG. 3 as follows. The front opening 64 must be unobstructed (e.g., the door 72 must be open). The first pair of chains 77 is removed from the hooks 75, and the cover 28 is then pushed or pulled toward the first end 24 of the skid 22, which thereby moves the space S to surround with the wellhead W. Guide wheels 94 inhibit misalignment of the cover 28 with the skid 22 during movement.

After the cover 28 is positioned around the wellhead W as shown in FIG. 3, the door 72 and cap pieces 70 may then be closed. The cover 28 may be secured in place by connecting the second pair of chains 79 to each of the anchor chains 81 on the runners 30, 32 using chain binders or similar means. It is anticipated, however, that other means of securing the cover in place may be used in addition to or alternative to the chain binders. For instance, wheel locks on other chains (not shown) may be welded to the skid 22 to connect with the hooks on other connecting members (not shown) on the frame 60 of the cover. Finally, one or more augers may be driven into the ground proximal to the skid 22 with a chain attached from the auger head to the skid 22 to inhibit skid movement relative to the wellhead W.

Thereafter, the cover 28 protects the wellhead W from falling debris and inadvertent contact with vehicles or other equipment at the worksite. Because the panels 76 and doors are steel mesh, the cover protects the wellhead while also allowing air movement for ventilation. The frustum shape of the cover 28 facilitates redirection of falling objects away from cover 28 and deflection of the full force of head on impacts to a surface of cover 28.

FIG. 4 shows a second embodiment 120 of the invention, and uses the same reference numbers for identical elements as described with reference to FIGS. 1-3. Only part of the skid 22 is shown. The cover 122 is identical to the cover 28 described supra, except for the cap 124 and the flaps 126.

In this second embodiment 120, when closed, the cap 124 forms a pyramid having four triangular cap faces 128. The cap 124 is made up of two identical pyramidal cap pieces 130 connected to the frame 60 with hinges 132 on opposing sides of the top opening 66. Each cap face 128 is formed by connecting flat bar steel pieces 129 into a triangle shape to form an opening, and then welding steel mesh 131 into or over the opening. While closed, each cap face 128 is inclined relative to the ground surface G at approximately thirty degrees, which facilitates falling objects that strike the cap 124 deflecting away from the embodiment 120.

The second embodiment 120 further comprises a number of steel flaps 126 connected to the frame 60 proximal to the bottom opening 62 with hinges 134. The flaps 126 are steel panels, which inhibit objects from inadvertently striking the wellhead W from underneath the cover 122 when the cover 28 is in the position described with reference to FIG. 3.

The present invention is described above in terms of specific embodiments of a wellhead protector. Those skilled in the art will recognize that alternative constructions of such an apparatus can be used in carrying out the present invention. Other aspects, features, and advantages of the present invention may be obtained from a study of this disclosure and the drawings, along with the appended claims.

Claims

1. A wellhead protector comprising:

a skid having a first runner with a first end and a second end, a second runner with a first end and a second end, said second runner spaced a distance from said first runner, and a first cross member connected between said first runner and said second runner;

a cover positioned above said skid, said cover having a closable opening in a wall of said cover, said cover having an opening at a bottom of said cover; and

a plurality one of rollers connected to said cover and in contact with said skid.

2. The wellhead protector of claim 1 further comprising at least one wheel guide connected to said cover proximal to said skid.

3. The wellhead protector of Claim 1 further comprising:

a second cross member connected between said first runner and said second runner at a position between said first cross member and said second ends of said first and second runners.

4. The wellhead protector of claim 1 further comprising a third opening at a top of said cover and a cap connected to said cover proximal to said third opening

5. The wellhead protector of claim 4 said cap having an apex, said space positioned between said first opening and said apex.

6. The wellhead protector of claim 4 wherein said cap comprises a first portion connected to said cover proximal to said third opening and a second portion connected to said cover proximal to said third opening, said first portion and said second portion converging to form said cap.

7. The wellhead protector of claim 1 a door connected to said frame proximal to said first opening.

8. The wellhead protector of claim 1 wherein said skid comprises:

a first vertical planar surface between said first and second ends of said first runner and said second end of said first runner; and

a second vertical planar surface between said first and second ends of said second runner said second runner.

9. The wellhead protector of claim 1 wherein said skid comprises:

a first horizontal planar surface between said first and second ends of said first runner and said second end of said first runner; and

a second horizontal planar surface between said first and second ends of said second runner said second runner.

10. The wellhead protector of claim 1 further comprising a wheel stop connected to at least one of said first runner and said second runner.

11. The wellhead protector of claim 1 wherein said distal ends of said first and second runners are upwardly angled.

12. The wellhead protector of claim 1 further comprising at least one panel hinged to said cover proximal to a bottom end of said cover.

13. The wellhead protector of claim 5 wherein said cap is tetrahedral.