Note: Descriptions are shown in the official language in which they were submitted.
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TELESCOPING DERRICK
Dackctround of the Invention
The present invention relates to a drilling derrick and a
method for erecting a drilling derrick on a fixed platform, a
jackup platform or on a floating barge. More particularly the
present invention relates to both the drilling derrick and method
of erection that produces a derrick of significant strength and
a capability of withstanding serious adverse weather,
environmental or geologic conditions.
Drilling derricks are well known in the art and are very
substantial structures that rise to a vertical height of at least
about 150 feet up to a maximum of near 190 feet. Unlike the masts
that are used for crane operation in oil field operations,
drilling derricks are necessarily four-sided structures that must
withstand the rigors of heavy winds and seas that include
hurricanes and typhoons or earthquakes or other earth tremors
that would topple far less sturdy structures. The drilling
derrick must be erected on site because of its great weight and
cannot be erected in a safe or quiet location and transported to
the site. It has in the past been attempted to have masts
constructed in sections and have the sections superposed one upon
the other at the drill site but such proposals are not successful
because with the height required for the drilling derrick, a
crane must lift very heavy sections 100 to 150 feet above the
drilling level or platform to effect the erection. Normally these
platform cranes are small to medium size having significant reach
and weight limitations and they are not tall enough to erect a
derrick in one piece.
If a crane on a floating barge is to be used to attain the
proper height, there is a great expense involved because the
offshore platforms are often located from a few miles to several
hundred miles offshore making the use of a very large barge crane
impractical and extremely expensive.
~ The prospect of installing on the drilling platform a crane
having the size and reach to be able to lift the drilling derrick
even in sections is uneconomical for any platform owner to
install such a huge crane capable of such erection of a drilling
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derrick in single or multiple lifts. This problem is particularly
acute because drilling contractors typically drill a group of
wells from a single platform and then move on to drill a group of
wells on a different nearby platform so that every time the ,
drilling rig -- comprising: a drilling derrick; supporting
structure; drilling machinery, etc.; used to drill a well bore
for each well -- must be moved from platform to platform. Thus
the rig must be rigged up for a new location and then broken down
to move by transport barge and a platform crane to a new
location. The frequency of the rig up and transportation has made
desirable some type of drilling derrick capable of being moved
and yet capable of withstanding the serious adverse conditions of
weather, environmental or geologic occurrences.
The current approach used by many drilling contractors is to
erect the drilling derrick in a piece-by-piece method that
enables the platform owner to achieve the desired drilling
derrick structure of a rigid and serviceable drilling derrick.
The problem, however, with this approach is it is labor intensive
and usually takes from several days to at least several weeks to
construct such a derrick in an piece-by-piece or stick-by-stick
method.
Another problem is posed by safety regulations promulgated
by the British and Norwegian governments that do not permit the
stick-by-stick building of a drilling derrick requiring at times
the rental of a huge semi-crane at a cost of several hundred
thousand dollars per day. Even that possibility for erection of
a drilling derrick is limited due to extreme weather conditions
in many areas such as the North Sea where it is reasonably
expected that an erection of a derrick could only be accomplished
within a period of six to eight months a year. For these and
other reasons experienced by those skilled in the art the problem
of erecting a drilling derrick sufficient to meet the severe
adverse conditions and to do so in an economical and safe manner ~
has been a problem facing the oil and gas industry.
S
Summary of the Invention
A telescoping four-sided drilling derrick that is to be
positioned on a drill floor over a well bore and is capable of
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withstanding severely adverse weather, environmental or geologic
conditions. The derrick is in several sections and includes a
bottom section, a top section and at least one intermediate
section all for superpositioning over the bottom section to form
a vertical four-sided tower. Each of the sections is composed of
vertical members positioned in each of the four corners of each
section to thereby form a total of four faces around the
perimeter of each section. Each of the faces in each section
includes at least one bracing cross member supporting adjacent
vertical members and at least one bracing cross member in the
bottom section being secured along an upper and minor portion of
the base of said bottom section so as to form a window. The
window is to be sufficiently large to receive consecutively
therebelow at least one section. In turn each of the intermediate
sections are inserted within the bottom section for subsequent
serial telescopic raising of the intermediate sections.
Thereafter support means is connected across the window after the
last intermediate section has been received within the bottom
section so as to substantially close the window and rigidify the
bottom section to enable the bottom section and the derrick to
withstand the stress imposed by the superposed sections and any
severely adverse conditions.
The method of erecting a four-sided drilling derrick for
positioning on the drill floor over a well bore and being capable
of withstanding severely adverse weather, environmental or
geologic conditions including steps of forming a four-sided tower
composed of a bottom section, top section, at least one
intermediate section superposed as a portion of the drilling
derrick. Constructing each of the sections with vertical members
positioned in each of the four corners of the sections forming a
face between adjacent members. Then bracing mutually adjacent
members with at least one cross member connected thereto and
~ connecting at least one bracing cross member along an upper and
minor portion of the face of said bottom section thereby forming
a window without bracing members below the bracing cross member.
The window is to be sufficiently large so as to receive in series
each of the intermediate sections therewithin. Thereafter,
inserting at least one intermediate section through the window
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into the bottom section and then telescoping each intermediate
section vertically upwardly serially upon the inserting and
thereafter closing the window by connecting support members
across the window to rigidify the bottom section to enable said
bottom section in the derrick to withstand the stress imposed by
the superposed section in any adverse conditions.
~escrit~tion of the Drawings
Figure 1 is a side view of the drilling derrick of the
present invention.
Figure 2 is an exploded view of the bottom section, a lower
section, a lower intermediate section, an upper intermediate
section, a top section and a crown frame and crown block section
at the very top of the drilling derrick.
Figure 3 is a side view of the bottom section prior to
insertion of any of the upper intermediate sections therein.
Figure 3A is a perspective view of the bottom section as
shown in Figure 3 illustrating the window on one side of the
bottom section.
Figure 4 is a cross-sectional view along lines 4-4 of Figure
3 illustrating the presence of the window on one side of the
bottom section.
Figure 5 is a view of the top section inserted down through
the top of the bottom section to a position on the drilling
floor.
Figure 6 is a cross-sectional view along lines 6-6 of Figure
5.
Figure 7 is a side view of the bottom section with inserted
top section and the superposed crown frame and block.
Figure 8 is a side view of the drilling derrick subsequent
to the telescoping of the upper intermediate section, top section
and crown frame and crown block.
Figure 9 is a side view of the joint derrick assembly after
additional intermediate sections have been telescoped upwardly.
Figure 10 is a perspective view partly broken away of the
latch assembly shown substantially enlarged from that of Figure
9.
Figure 11 is a perspective view partly broken away of the
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latch assembly in a supporting mode enlarged from the showing at
Figure 9.
Figure 12 is a cross-sectional view taken along line 12-12
of Figure 11.
Figure 13 is a side view illustrating the telescoping frame
used for raising the telescoping sections.
Figure 14 illustrates the completed telescopic movement of
the sections using the telescoping frame.
Description of the Preferred Embodiment
The completed derrick directed in accordance with the
present invention is shown in Figure 1 generally at 20. In Figure
2, an exploded view, the individual sections of the derrick 20
are clearly illustrated. The principal sections are bottom
section 22, lower section 24, lower intermediate section 26,
upper intermediate section 28, top section 30 and crown section
32 shown attached to the top of top section 30 along with crown
block 34 positioned within the crown section 32. The derrick 20
is positioned on drill floor F by conventional means that
securely fastens the bottom 36 of bottom section 22 to the drill
floor F. As is conventional, the drilling derrick 20 is
positioned over the drill hole, not shown, but always positioned
along the center line axis of the derrick 20. The perspective
view of the bottom section, as illustrated in Figure 3A, depicts
the structure of the bottom section more clearly and attention is
directed thereto. As can be readily seen, the bottom section is
composed of four vertical members each being positioned in the
corner of the cross section of the bottom section illustrated at
38a through 38d. Each pair of vertical members forms a face
respectively 40a, 40b, 40c and 40d. Each face is therefore
bordered on two sides by a pair of vertical members 38a through
38d. For instance, face 40a is formed across the space between
~ vertical members 38a and 38b. Likewise face 40b is formed between
vertical members 38a and 38d. Similarly face 40c is formed
between vertical members 38b and 38c and face 40d is formed
between vertical members 38c and 38d.
As more clearly depicted in Figure 3A, each of three faces,
40b, 40c and 40d is obstructed by supporting cross members 42b,
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42c and 42d. For example, supporting cross members 42b, 42b
extend across face 40b. These cross members are angled to be
secured to the bottom 36 of the bottom section at 45 for each of
the angled cross members 42b, 42b and at their respective upper
ends are secured to a cross member 44b that may be horizontal as
shown that braces the vertical members. Similarly, in each of
faces 40c and 40d corresponding bracing cross members 42c, 42c _
and 42d, 42d that may be angled as shown are positioned and
secured to their respective horizontal bracing cross member 44b,
~4c or 44d.
Face 40a alone is not initially provided with any of the
angled cross members such as 42b through 42d and the space
bordered on the top by bracing cross member 44a and vertical
members 38a and 38b constitutes a window 46 that is completely
unobstructed and allows totally free access to the interior of .
the bottom section 22.
Extending above the window 46 and in particular above
horizontal cross member 40a is an upper horizontal cross member
48a that along with similar upper horizontal cross members 48b,
48c and 48d are attached to the upper extremities of vertical
members 38a, 38b, 38c and 38d for the purpose of forming a more
rigid bottom section. Upper angled cross members 50 numbering two
are secured in each area between the lower horizontal cross
members 44a through d and upper horizontal cross members 48a
through d. Additional support members 52 not constituting a
meaningful part of the invention are provided between adjacent
angled cross members 42b through d and corresponding adjacent
vertical members 38a through d.
As is quite apparent from Figures 3 and 4 the. interior
within the bottom section 22 is completely open below the upper
horizontal cross members 48 and capable of receiving axially
therethrough an upper section for telescopic raising. It is also
to be noted that the bottom section 22 as best shown again in
Figure 3A but also in Figure 3 is provided with a window 46 that
is unobstructed and free of any structural encumbrances or
support members.
-In Figures 1 and 2, there are shown the additional sections
that are used to erect the derrick of the present invention. The
AMENDED T
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structural elements and the construction of lower section 24,
lower intermediate section 26, upper intermediate section 28 and
top section 30 are all similar to that described in detail with
respect to bottom section 22. However the cross members 42, 44
and structural members 52 are slightly changed. It should be
understood, however, that the sections 24 through 32 do not
constitute an aspect of the present invention and are essentially
conventional.
The window 46 is a prominent aspect of the present invention
and can be readily viewed in Figures 3, 3A and 4. This window is
designed to be of such height from the drill floor F to the
bottom of the lower horizontal cross member 44a in order to
receive therein lower intermediate section 26 and thereafter
lower section 24 for consecutive telescopic movement upwardly.
In the erection of the derrick of the present invention,
upper intermediate section 28 is first raised by a crane, not
shown, and deposited axially downwardly within the bottom section
28 so that the bottom 54 of upper intermediate section 28 rests
on the drill floor F, as best shown in Figure 7. In that position
the top section 30 with crown section 34 and crown block 34 may
be axially superposed in a conventional manner on top of upper
intermediate section 28 again as shown clearly in Figure 7.
Thereafter as shown in Figure 8 both the upper intermediate
section 28 and top section 30 with the additional crown section
32 and crown block 34 are elevated telescopically and retained in
place as seen in Figure 8 by means and methods that will be
hereafter described in detail.
The method of the present invention is quite apparent from
the Figure 8 position of the partially erected derrick. It can be
seen that the lower intermediate section 26 may then be
positioned below the upper intermediate section 28 by passing the
lower intermediate section 26 through the window 46 and into
~ alignment with the upper intermediate section 28. The lower
intermediate section then is telescopically raised along with the
E previously installed upper intermediate section and top section
to make room below the lower intermediate section 26 for the next
section, for the lower section 24, to be inserted through the
window 46 in the manner precisely the same as the lower
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intermediate section 26 had been inserted through the window 46.
In such position then the lower section may be telescopically
raised which is in turn raising lower intermediate section 26,
upper intermediate section 28 and top section 30. ,
After each of those sections has been raised, the erection
of the derrick will take the appearance as shown in Figure 9 _
wherein the derrick 20 has been erected to its final height and
all sections have been telescopically raised into proper
position. Each of the sections is connected one to the other in
a conventional manner.
The means used for telescopically raising the sections is
shown in Figures 13 and 14. The telescopic mechanism includes
line 56 depending from and reeved through crown block 34 and
operated through draw works, not shown. At the end of line 56 is
a hook 58. The hook 58 engages a bar 59 around which the scoping
line 60 is reeved. Scoping line 60 is continuous on both sides of
the bar 59 as shown in Figures 13 and 14 and is reeved around
sheaves 61 and attached to the opposed upper horizontal cross
members 48b and 48c at 62. The sheaves 61 are positioned at the
ends of the scoping frame 64.
Scoping frame 64 is shown as a bar but may be in the form of
a frame coextensive with of the section to be telescopically
raised and is attached for instance in any convenient and
conventional manner to the inside of the vertical members 66 on
the upper intermediate section. For each of the succeeding
sections to be telescopically raised, the frame would be
similarly attached to the inside of the corresponding vertical
members also shown as 66.
When the scoping bar of frame 64 is securely attached as by
bolts to the respective section at or near its bottom, the line
56 is drawn upwardly by the draw works and as such the hook 58
pulls up the equalizing bar 59 to continually allow each segment
of line 60 to be equal in length as the segments extend down to
their respective sheaves 61, 61. When the scoping frame 64 is
raised up from the position shown in Figure 13 to that shown in
Figure 14, it is desired to hold the telescopically raised
section to be held in position so that the next lower section may
be inserted through the window 46 and attached to the bottom of
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the previously telescopically raised section.
Figures 9, 10, 11 and 12 are directed to the latch shown
generally at 68 for holding the previously telescopically raised
sections. Latch 68 is composed of a pair of opposed pivoting arm
plates 70, 70 that are positioned on vertical members 38a and
38b. Each plate 70 is provided with an abutment surface 72 for
contact with abutment 74 suitably secured to the opposite sides
of vertical members 66 as best shown in Figure 12. Arm plates 70
are pinned together through appropriate opening 75 in web 76 of
vertical member 38a and 38b by means of bolt 77. Similarly, bolt
78 is designed to pass through opening 79 in web 80 of vertical
member 66 to secure the latch in place as it abuts the abutment
74. In a similar fashion bolt 81 is added for further security
and acts in a manner similar to bolt 78 but on vertical member
38a. Pivot mechanism 82 pivots the latch 68 about pin 77 as an
axis. Bar 83 is secured between the inside surfaces of the
respective arm plate 70, 70 and is offset from pivot axis of bolt
77 so that movement of yoke 83 pivotally secured at 84 to cross
bar 85 will pivot the latch 68 about axis 77 as the yoke is moved
upwardly or downwardly. Yoke 83 is operated by control rod 85 so
as to move the latch 68 into and out of positions shown in
Figures to and 11.
As can be readily seen from Figures 9 through 12 as the
sections are telescopically raised by the scoping frame 64, the
abutment 74 rises above the level of latch 68 sufficiently high
to allow latch 68 to pivot downwardly from its inoperative
position shown in Figure 10 to move the latch from its
inoperative position in Figure 10 to its operative position in
Figure 11. Control rod is raised upwardly pivoting latch 68 about
the axis 77 so as to allow abutment surface 72 to engage abutment
74 upon the section and therefore vertical member 66 being
lowered into abutment contact as shown in Figures 11 and 12. In
such position the previously telescopically raised section is
fully and completely supported by the latch after suitable pins
- 78 and 81 have been inserted for security and safety reasons.
As best seen in Figures 1, 7 , 8 and 9 the control rod 85
extends down along each vertical member 38a and 38b to the drill
floor F where a suitable control handle 86 is present. Of course,
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it is to be understood that the control rod may be operated
electrically or hydraulically by any suitable means that are well'
known to those skilled in the art and is not limited to the
mechanical arrangement that has been discussed above. It should _
be evident that having the control operation for the latch 68
operable from the drill floor, it is not necessary for working
personnel to be up on the derrick to the extent that had been
previously required when more secure connective means was
required. Now the assembly of several pins makes the mutual
securing of the sections simple and easy after being
telescopically moved upwardly.
A service platform 88 and suitable access ladder best shown
in Figure 3A, is added for convenience of the workers to provide
whatever maintenance is necessary and of course to install the
bolts as may be necessary.
Once the upper intermediate section is telescopically moved
upwardly from the position shown in Figure 7 to that shown in
Figure 8 and the latch is engaged as shown at Figure 8, the
scoping frame 64 is lowered' and installed at the bottom end of
the next section to be scoped upwardly, the lower intermediate
section 26. When the lower intermediate section 26 is assembled
and set on the drill floor F in front of the window 46 of the
bottom section 22 the lower intermediate section 26 may be pulled
inside the window 46 by winches and wirelines not shown so that
the lower intermediate section 26 is aligned with the previous
scoped telescopically raised upper intermediate section 28. At
that time the control rod is operated to disengage the latches
from the abutment 74 upon the raising of the upper intermediate
section 28 using the scoping frame 64 to the point that the
abutment rises above the reach of the arm plate 70 of the latch
and then the upper intermediate section is lowered onto the top
of the lower intermediate section 26 where they are bolted
together in conventional fashion. The scoping frame 64 has been '
lowered and installed at the bottom end of the lower intermediate
section 26 for a repeat of the previous telescoping movement.
After the successive sections, the lower intermediate
section 26 and the lower section 24 and any other section that
may be desired to be telescopically raised to heighten the
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derrick the assembly will take on the appearance as set forth in
Figure 9. In this state, the window 46 that had permitted the
access of the intermediate sections for raising to heighten the
derrick becomes a liability because of the inherent weakness and
lack of rigidity created by the unsupported space constituting
the window 46. It is one important aspect of the present
invention that the window be secured and braced using support
members 42a and 42b that are angled from the bottom of the bottom
section 36 up to essentially the mid-point of the horizontal
cross member 44a as best shown in Figure 1. Suitable additional
structural members 52 may be added as shown to close the window
46 and provide the structural rigidity necessary for a derrick of
superior height and allow it to withstand the adverse conditions
that are to be anticipated for this drilling derrick.
It must be understood that the number, type or location of
the support members 42a and 42b is not critical provided that the
window 46 that was previously open to admit derrick sections is
now closed to provide added rigidity to the derrick.
When disassembling the drilling derrick the procedure must
be reversed and the window 46 must be opened by removing the
support cross members 42a and 42b along with the structural
members 52 and the scoping frame attached to the bottom of the
section to be lowered the latch 68 opened and the entire derrick
above the bottom section lowered to the drill floor where the
process, the reverse of the erection process is continued.
From the foregoing it is believed that the intentions and
purposes of the invention have been met and that the invention
should be limited solely by the appended claims wherein I claim:
