U.S. patent number 3,747,695 [Application Number 05/131,630] was granted by the patent office on 1973-07-24 for high floor pivoted mast drilling rig.
This patent grant is currently assigned to Pyramid De rick and Equipment Corporation. Invention is credited to Donald R. Branham.
United States Patent |
3,747,695 |
Branham |
July 24, 1973 |
HIGH FLOOR PIVOTED MAST DRILLING RIG
Abstract
A framework type mast structure is pivotally mounted on a base
structure. A self-supporting pedestal structure including a gin
pole structure which is pivotally mounted on the base structure
adjacent the mast structure. The pedestal structure with the gin
pole is tilted to vertical position, and the gin pole secured.
Sheaves carried by the gin pole cooperate with a sling line which
runs to and is looped over the hook of the traveling block of the
drilling rig for purposes of raising the mast structure to an
upright position. A second self-supporting pedestal structure is
tilted into position on the base structure on the other side of the
mast structure and below a racking board assembly carried by the
mast structure which is used to support the lower end of racked
drill pipe independently of the mast structure. A rotary table is
supported independently of the mast structure by means of a
horizontal support structure which extends through the framework of
the mast structure and is supported by the two pedestal structures.
A working floor is carried by the gin pole pedestal structure
which, together with the rotary table and the pipe supporting floor
of the second pedestal structure, is positioned at an elevated
location above the base structure. In a second embodiment, a
separate gin pole structure is not used and the mast raising
sheaves are instead mounted on the main body of the first pedestal
structure.
Inventors: |
Branham; Donald R. (Houston,
TX) |
Assignee: |
Pyramid De rick and Equipment
Corporation (Houston, TX)
|
Family
ID: |
22450309 |
Appl.
No.: |
05/131,630 |
Filed: |
April 6, 1971 |
Current U.S.
Class: |
173/151; 52/116;
175/52; 52/110; 52/125.2 |
Current CPC
Class: |
E21B
15/00 (20130101) |
Current International
Class: |
E21B
15/00 (20060101); E21b 015/00 () |
Field of
Search: |
;52/120,111,121,117,116,110,112-115,118,119,143 ;173/151
;175/85,52 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Purser; Ernest R.
Claims
What is claimed is:
1. A high floor pivoted mast drilling rig comprising:
a base structure;
an upright framework type mast structure pivotally mounted on the
base structure;
a first self-supporting pedestal structure mounted on the base
structure on one side of the mast structure pivot axis for
supporting a working floor at an elevated position above the base
structure;
a racking board assembly carried by the mast structure at an upper
location thereon and extending outwardly from the mast structure on
the side farthest removed from the first pedestal structure;
a second self-supporting pedestal structure mounted on the base
structure on the other side of the mast structure pivot axis and
below the racking board assembly for supporting the lower end of
racked drill pipe independently of the mast structure and at an
elevated position above the base structure; and
a rotary table support structure extending through the framework of
the mast structure and supported by the first and second pedestal
structures at an elevated position above the base structure for
supporting a rotary table independently of the mast structure.
2. A drilling rig in accordance with claim 1 and including sheave
means supported by the first pedestal structure for use in raising
the mast structure to an upright position.
3. A drilling rig in accordance with claim 1 and including gin pole
means carried by the first pedestal structure and base structure
and extending upwardly therefrom and a plurality of sheaves
rotatably carried by the upper portion of the gin pole means for
use in raising the mast structure to an upright position.
4. A drilling rig in accordance with claim 1 and including a
plurality of sheaves rotatably mounted on the first pedestal
structure for use in raising the mast structure to an upright
position.
5. A drilling rig in accordance with claim 1 wherein the first and
second pedestal structures are detachably connected to the base
structure.
6. A drilling rig in accordance with claim 1 wherein the first and
second pedestal structures are boxlike framework type structures
having four legs pinned to the base structure.
7. A drilling rig in accordance with claim 1 and including a rotary
table mounted on the rotary table support structure and located so
that the center of the rotary tabel is within the confines of the
framework of the mast structure.
8. A drilling rig in accordance with claim 7 an including hoisting
means carried by the mast structure, draworks located adjacent the
first pedestal structure at an elevation considerably lower than
the elevation of the rotary table support structure, an independent
rotary drive mechanism carried by the first pedestal structure at
about the same elevation as the rotary table and linkage means for
operatively coupling the rotary drive mechanism to the rotary
table.
9. A drilling rig in accordance with claim 1 wherein the rotary
table support structure comprises a skid structure resting on an
upper portion of the first pedestal structure and extending through
the framework of the mast structure and connected to an upper
portion of the second pedestal structure.
10. A drilling rig in accordance with claim 9 wherein the skid
structure carries a rotary table the center of which is loacted
within the confines of the framework of the mast structure, a
rotary drive mechanism located to the first pedestal structure side
thereof and linkage means operatively coupling the rotary drive
mechanism to the rotary table.
11. A drilling rig in accordance with claim 1 wherein the rotary
table support structure comprises a horizontally extending frame
structure connected at one end to the first pedestal structure and
connected at the other end to the second pedestal structure and the
drilling rig includes a rotary table carried by this horizontally
extending frame structure and located so that the center of the
rotary table is within the confines of the frameowrk of the mast
structure.
Description
BACKGROUND OF THE INVENTION
This invention relates to a high floor pivoted mast drilling rig
for drilling bore holes into the earth. While not limited thereto,
the invention is particularly useful in drilling oil wells, gas
wells, and other mineral producing bore holes into the earth.
As oil wells are drilled deeper and deeper, it becomes more
desirable to use drilling rigs having taller masts and higher
substructures. The taller the mast, the fewer the pipe joints that
have to be broken in a given length of drill pipe coming out of the
hole, thus enabling trips to be made in a more rapid manner. Also,
deeper wells encounter high pressures, thus necessitating the use
of more and larger safety equipment between the well head and the
working floor of the drilling rig. To provide clearance for such
safety equipment, the substructure supporting the working floor
must be relatively high. The taller the mast and substructure, the
greater the problems involved in erecting, disassembling and
transporting the rig from one location to another.
The labor and time expended in assembling and disassembling the
drilling rig can be minimized by utilizing a pivoted mast type of
drilling rig wherein the mast is pivotally connected to a base
structure and is raised to its upright position by means of a gin
pole structure secured to the base structure adjacent the mast
pivot point. The elevated working floor is provided by a floor
structure carried by the mast and additional floor structures which
are pinned to the mast and to the gin pole structure. A typical
form of drilling rig of this type is described in U. S. Pat. No.
3,262,237 granted to Jenkins et al. on July 26, 1966.
While drilling rigs of the type described in this U.S. Pat. No.
3,262,237 do largely achieve the desired objective of simplifying
the assembly and disassembly procedures, they nevertheless suffer
from various disadvantages and drawbacks. For one thing, the
setback portion of the working floor which carries the weight of
the racked drill pipe is pinned to and supported in part by the
drilling mast. This places an undesirable additional strain on the
mast structure. For another thing, the rotary table is supported by
a portion of the floor structure which is mounted on the drilling
mast. Consequently, vibrations and other movements of the rotary
table occurring when drilling through hard formations are
transferred directly to the drilling mast which, in turn, tends to
cause the whole mast to shake or vibrate. These problems can, of
course, be overcome in part by strengthening the mast by using a
more elaborate framework construction for the mast structure and by
using heavier structural members for such framework. This, however,
increases the expense of the mast structure and the expense and
difficulty of transporting same from one well site to another.
SUMMARY OF THE INVENTION
It is an object of the invention, therefore, to provide a new and
improved high-floor pivoted-mast drilling rig having an improved
form of construction.
It is another object of the invention to provide a new and improved
high-floor pivoted-mast drilling rig wherein the drilling mast is
not required to support any of the weight of racked drill pipe.
It is a further object of the invention to provide a new and
improved high-floor pivoted-mast drilling rig wherein rotary table
vibrations are not directly transferred to the mast structure.
In accordance with one feature of the invention, a high-floor
pivoted-mast drilling rig comprises a base structure and a
framework type mast structure pivotally mounted on the base
structure. A first self-supporting pedestal structure is mounted on
the base structure on one side of the mast structure pivot axis for
supporting a working floor at an elevated position above the base
structure. A racking board assembly is carried by the mast
structure at an upper location thereon and extends outwardly from
the mast structure on the side farthest removed from the first
pedestal structure when the mast structure is in an upright
position. A second self-supporting pedestal structure is mounted on
the base structure on the other side of the mast structure pivot
axis and below the racking board assembly for supporting the lower
end of racked drill pipe independently of the mast structure and at
an elevated position above the base structure.
In accordance with another feature of the invention, the drilling
rig includes a rotary table support structure which extends through
the framework of the mast structure and is independently supported
by first and second self-supporting pedestal structures located on
opposite sides of the mast structure. Such support structure serves
to support a rotary table at an elevated position above the base
structure independently of the mast structure.
For a better understanding of the present invention, together with
other and further objects and features thereof, reference is had to
the following description taken in connection with the accompanying
drawings, the scope of the invention being pointed out in the
appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
Referring to the drawings:
FIG. 1 is an elevational view of a high-floor pivoted-mast drilling
rig constructed in accordance with the present invention;
FIG. 2 is an elevational view of the mast portion of the FIG. 1
drilling rig taken at right angles to the elevational view of FIG.
1 along section line 2--2 thereof;
FIG. 3 is a plan view taken along section line 3--3 of FIG. 1;
FIGS. 4, 5 and 6 show different steps in the assembly and erection
of the FIG. 1 drilling rig; and
FIG. 7 is a partial elevational view showing modified forms of
construction for portions of the FIG. 1 drilling rig.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to FIGS. 1-3, there is shown a high-floor pivoted-mast
drilling rig in its assembled condition as it would appear when
drilling an oil well or gas well or other type of borehole into the
earth. The drilling rig includes a relatively tall substructure 10
for supporting a working floor 11 at an elevation some 20 feet or
more above the ground level 12. A mast structure or drilling mast
13 extends upwardly some 140 feet or more above the working floor
11. The substructure 10 includes a base structure 14 resting on the
ground surface 12 and comprised of a pair of box-like framework
structures 15 and 16 (FIG. 3) interconnected by appropriate
horizontal tie beams (not shown). The bottom ends of the two side
frames of the mast 13 are pivotally mounted in a pair of shoes 17,
one of which is mounted on each of the box structures 15 and 16 of
the base structure 14.
The substructure 10 further includes a first self-supporting
pedestal structure 18 mounted on the base structure 14 on one side
of the mast structure pivot shoes 17. The pedestal structure 18 is
of a box-like framework type construction having four legs 19 which
are detachably pinned to four shoes 20 mounted on the base
structure 14. Two of the shoes 20 are mounted on the base box
structure 15, while the other two are mounted on the base box
structure 16. Legs 22, 23 form gin pole structure 21, the legs 22
being carried by the pedestal structure 18, and legs 23 are
connected to legs 22 at their upper end and extend therefrom and
are pinned on the base structure 14. A pair of legs 22 is provided,
one each on each side of the pedestal structure 18, and a pair of
legs 23, one being pinned at its lower end to structure 15 and one
being pinned at its lower end to structure 16. A plurality of
sheaves 24, 25, and 26 is rotatably mounted at the top of the gin
pole 21 by means of a shaft 27 which, as indicated in FIG. 2,
extends between the spaced gin pole legs 22 and 23 where they are
connected at their upper ends. The center sheave 25 is mounted so
that it can also slide back and forth on the shaft 27. A walkway
support extension 28 is pivotally pinned across the back side of
the pedestal structure 18 and, when horizontally extended, is
supported by a brace 29 extending therefrom to the pedestal
structure 18.
The substructure 10 also includes a second self-supporting pedestal
structure 30 mounted on the base structure 14 on the other side of
the mast structure pivot shoes 17. This second pedestal structure
30 is also of a box-like framework construction having four legs 31
detachably pinned to 4 shoes 32 mounted on the base structure 14, 2
such shoes being mounted on the base box structure 15 and the other
two being mounted on the base box structure 16 thereof. A working
floor surface 33 covers the top of the pedestal structure 30. As
indicated in FIG. 3, the center portion of this surface 33 is
formed by a series of wooden planks 34 which form a pad for
supporting the lower ends of lengths of racked drill pipe. A
walkway extension 35 is pivotally pinned across the right-hand side
of the pedestal structure 30, such extension 35 being supported by
a brace 36 when in its extended position.
The mast structure 13 is of a framework construction and includes
an upper tower portion 13a and a lower stub portion 13b, the latter
of which narrows down to provide the feet which are pivotally
pinned to the base structure shoes 17. The tower portion 13a is
made up in sections which are pinned together and the lower-most
section thereof is, in turn, pinned to the stub section 13b. The
tower portion 13a is comprised of four vertically extending frame
members 37 defining the four corners thereof and interconnected on
three sides of the mast 13 by series of horizontal and diagonal
braces 38. No cross braces are provided on the side of the mast 13
facing the second pedestal structure 30 so that this side of the
mast is open. As indicated in FIGS. 2 and 3, the stub portion 13b
is comprised of a pair of side frames 40 and 41 which extend
downwardly and are pinned to the base structure pivot shoes 17.
When in its upright position as shown, the mast structure 13 is
pinned to the top of the gin pole structure 21 by means of coupling
brackets indicated at 42. A pair of spaced apart sheaves 43 (only
one of which is visible in FIG. 1) are rotably carried near the top
of the stub portion 13b for cooperating with the gin pole sheaves
24 and 26 when raising the mast 13 to its upright position. A pair
of brackets 44 are mounted on the rearward legs 37 of the mast 13,
also for use in raising the mast 13.
The mast structure 13 carries a hoisting mechanism which includes a
traveling block 45 which is suspended from a crown block 46 by
multiple loops of a drilling line 47. The live end of the drilling
line 47 leaves the crown block 46 by way of a sheave 48 and runs
downwardly to the wench drum of a drawworks 49. The mast structure
13 further carries a racking board assembly 50 at an upper location
thereon. The racking board assembly 50 extends outwardly over the
second pedestal structure 30 and includes the usual pipe racks for
holding the upper ends of lengths of drill pipe. Several stands of
drill pipe are indicated at 51. The lower ends of such pipe stands
51 rest on the pad 34 on top of the pedestal structure 30 and the
upper ends are held by the racks in the assembly 50.
The drawworks 49 is positioned adjacent the first pedestal
structure 18 and is supported by a suitable support structure 52.
Drawworks 49 is driven by a set of engines 53 which are supported
by an appropriate support structure 54, the drive linkage between
the engines 53 and drawworks 49 being omitted for sake of
simplicity.
The drilling rig further includes a rotary table support structure
which extends through the framework of the mast structure 13 and is
supported by the first and second pedestal structures 18 and 30 at
an elevated position above the base structure 14 for supporting a
rotary table 55 independently of the mast structure 13. In the
present embodiment, this support structure takes the form of a skid
structure 56 which extends over and rests on the cross beams of an
upper portion of the first pedestal structure 18. The right-hand
end of the skid 56 extends through the framework of the mast
structure 13 and is pinned to the second or right-hand pedestal
structure 30. In addition to the rotary table 55, the skid 56
carries an independent rotary drive and catworks mechanism 57. The
rotary drive portion of this mechanism 57 is operatively coupled to
the rotary table 55 by an appropriate linkage mechanism which, for
simplicity of illustration, is not shown in the drawings. As
indicated in FIG. 1, the center of the rotary table 55 is located
within the confines of the framework of the mast structure 13.
Since there is no direct connection or contact between the skid 56
and the mast structure 13, the rotary table 55 is thus supported
independently of the mast structure 13. This minimizes the transfer
of vibrations from the rotary table 55 to the mast structure 13.
The upper end of a string of drill pipe 58 is shown in FIG. 1 as
being held by the rotary table 55. For simplicity of illustration,
the blowout preventors and other safety equipment located below the
rotary table 55 are not shown. The deck panels forming the working
floor 11 are laid out around the skid 56 and supported at a slight
elevation above such skid 56 by means of support braces and cross
beams carried by the first pedestal structure 18 and the walkway
support extension 28.
The drilling rig of FIGS. 1-3 is a portable type drilling rig which
may be transported to a well site in a disassembled condition and
then assembled and erected to the condition shown in FIGS. 1-3.
Referring now to FIGS. 4-6, the method of assembling the drilling
rig will now be considered. As indicated in FIG. 4, the first step
is to locate the base structure 14, the drawworks support 52 and
the engine support 54 in the proper relationship to one another on
the ground surface 12. At this time, the tie beams running between
the two side boxes 15 and 16 of the base structure 14 are
installed. Next, the gin pole supporting pedestal 18 is erected in
horizontal position and then elevated to vertical position with the
aid of a separate truck mounted gin pole. FIG. 4 illustrates in
dotted line the gin pole pedestal 18 in the horizontal position,
and in this position, the left-hand legs of the pedestal structure
18 are pinned to the left-hand pair of shoes 20 on the base
structure 14. The pedestal 18 is then pivoted to the upright
position shown in solid line by means of the separate gin pole
truck, and the right-hand legs of the pedestal 18 are then pinned
to the right-hand shoes 20 on the base structure 14. Alternatively,
the pedestal structure 18 could be raised to the upright position
by means of a hydraulic cylindrical mechanism connected between the
base structure 14 and the left-hand side of the pedestal structure
18. Following erection of the pedestal structure 18, the drawworks
49 and the drawwork engines 53 are set in place on their respective
support structures 52 and 74, this condition being indicated in
FIG. 5. The gin pole 21 is then formed by connecting legs 22 at
their lower end to the top of structure 18, connecting the lower
end of legs 23 to substructure 14 and the upper ends of legs 22, 23
together with shaft 27 extending between the legs 22, 23 on one
side with the legs 22, 23 on the other side of structures 18 and
14.
Proceeding now to the erection of the mast structure 13, the stub
section 13b thereof is placed in a horizontal position as indicated
in outline form in FIG. 5, and the feet of the two stub section
side frames are pinned in place in the pivot shoes 17. With the aid
of the separate gin pole truck and a suitable support stand, the
lowermost section of the tower structure 13a is pinned to the stub
section 13b and thereafter the further sections of the tower
structure 13a are pinned to one another in an end-to-end manner to
form the completed tower structure, the support stand being moved
further to the right as each section is added. The crown block
structure is pinned to the far end of the last such tower section.
The traveling block 45 is then positioned within the mast structure
13 and the drilling line 47 is reeled off the drawworks 49 and
reaved between the crown block 46 and the traveling block 45, the
dead end of line 47 being connected to an appropriate anchor on the
base structure 14. At this time, the drilling line 47 passes over
the gin pole sheave 25 located behind the gin pole sheave 24 in
FIG. 5.
The next step is to string up a sling line 60. One end of this
sling line 60 is tied to the forwardmost one of the brackets 44 in
FIG. 5. From there, the sling line 60 runs over the gin pole sheave
24, then over the forwardmost one of the mast-mainted sheaves 43
and is then looped over the hook of the traveling block 45. From
there, the sling line 60 passes back over the rearwardmost one of
the mast-mounted sheaves 43, then back over the rearward gin pole
sheave 26 and is then tied to the rearward one of the brackets 44.
To raise the mast 13, the drawworks 49 is operated to move the
traveling block 45 to the right. This pulls the lower spans of the
sling line 60 toward the right which, in turn, raises the mast
structure 13. The mast structure 13 is first raised off the ground
a sufficient distance to allow the pinning on of the racking board
assembly 50. Thereafter, the mast structure 13 is raised to its
vertical position as indicated by the solid line construction in
FIG. 5. The mast structure 13 is then pinned to the gin pole
structure 21 by means of the coupling brackets 42. Thereafter, the
sling line 60 is untied and removed from the mast structure 13.
Next, the walkway support extension 28 is swung up to its
horizontal position and braced by brace 29, as shown in FIG. 6.
Then, the skid 56 carrying the rotary table 55 and the rotary drive
and catworks mechanism 57 is raised by means of the traveling block
45 and moved onto the gin pole pedestal structure 18. At this time,
the skid 56 is moved a sufficient distance to the left to that it
is completely supported by the pedestal structure 18. Thereafter,
the pipe setback pedestal structure 30 is moved into the horizontal
position indicated in solid line in FIG. 6. The right-hand legs of
the pedestal structure 30 are then pinned to the right-hand shoes
32 on the base structure 14. Thereafter, a tie line 61 is connected
between the setback pedestal structure 30 and the hook of the
traveling block 45. Traveling block 45 is then raised to move the
setback pedestal structure 30 to its upright position as indicated
by the dash line construction in FIG. 6. Tie line 61 is then
removed and the left-hand legs of the pedestal strucutre 30 are
pinned to the left-hand shoes 32 on the base structure 14. The skid
56 is then moved to the right until it contacts the setback
pedestal 30, following which the right-hand end of the skid 56 is
pinned to the pedestal structure 30 by way of appropriate pins and
coupling brackets. The deck panels forming the working floor 11 are
then set in place, as are the various handrails, stairs, ramps and
other auxiliary structures normally associated with a drilling rig.
The drilling rig is then in a condition to commence the drilling of
a borehole into the earth.
Referring now to FIG. 7, there is shown a modified form of
construction for both the rotary table support structure and the
gin pole structure. The parts which remain the same as in the FIG.
1 embodiment are identified by the same reference numerals as in
FIG. 1. As seen in FIG. 7, the two self-supporting pedestal
structures 18 and 30 are pinned to the base structure 14 on
opposite sides of the mast structure 13 in the same manner as in
the FIG. 1 embodiment. In the FIG. 7 embodiment, however, the
rotary table support structure is comprised of a horizontally
extending frame structure 62 which is pinned at one end to the
first pedestal structure 18 and at the other end to the second
pedestal structure 30. This frame structure 62 includes front and
rear beams,only the first of which is visible in FIG. 7, which
extend between the pedestal structures 18 and 30, together with
appropriate crossbeams running therebetween. The rotary table 55 is
carried by the frame structure 62. Such frame structure 62 extends
through the framework of the mast structure 13 and is not in direct
contact therewith so that the rotary table 55 is supported
independently of such mast structure 13. The rotary drive and
catworks mechanism 57 in this embodiment is supported atop the
pedestal structure 18, there being no skid used in this
embodiment.
In place of the gin pole structure of the earlier embodiment, the
sheaves used in raising the mast structure 13 are, in the FIG. 7
embodiment, rotatably mounted directly on the pedestal structure
18. More particularly, a pair of front and rear sheaves 63, only
the front one of which is visible in FIG. 7, are used to handle the
sling line used in raising the mast structure 13. As such, they
take the place of the sheaves 24 and 26 of the earlier embodiment.
A further sheave 64 is rotatably mounted at the back end of the
pedestal structure 18 and in a central position along the backside
thereof. This sheave 64 is used for guiding the drilling line 47
when raising the mast structure 13. As such, the sheave 64 takes
the place of the gin pole sheave 25 of the FIG. 1 embodiment.
Except for the foregoing differences, the remainder of the drilling
rig of FIG. 7, including the parts not shown, may be of the same
construction as described in connection with the FIG. 1
embodiment.
While there have been described what are at present considered to
be preferred embodiment of this invention, it will be obvious to
those skilled in the art that various changes and modifications may
be made therein without departing from the invention, and it is,
therefore, intended to cover all such changes and modifications as
fall within the true spirit and scope of the invention.
* * * * *