Note: Descriptions are shown in the official language in which they were submitted.
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Modular lightweight drilling rig.
The present invention regards a modular lightweight drilling rig in accordance
with the
preamble of the appended Claim 1.
Traditionally, a drilling rig is put up by a structure being assembled from
basics directly
on a platform, i.e. on the platform deck. This structure comprises a
substructure
containing service functions such as pumps, compressors and other equipment,
and
m defines a drilling deck on top of the substructure. The actual derrick is
arranged on this
drilling deck. Such construction is time consuming, and must be closely co-
ordinated in
order to avoid delays, e.g. due to components not being ready when they are
due to be
assembled.
~ s Another much used method is to build the entire structure up separately
from the
platform and then place it on the platform, for instance by lowering the
platform so that
the structure may be guided into place e.g. by a barge. This method requires
the use of
expensive high capacity equipment in order to guide the structure into place.
It also
entails great risks.
zo
Attempts have been made to construct such a structure by use of modules,
however
none of the attempts so far have been particularly successful. Examples in
this respect
are shown in:
DE 1009575, which shows a land based drilling rig assembled by modules.
However,
this rig is designed to be used on land, and will not be suitable offshore.
SU 1709059, which shows a rig consisting of a large number of rectangular
modules.
The modules are placed two and two in each level. The modules of adjoining
storeys are
placed in right angle to each other, in the same way as a match tower. This
means that
the access to the interior of the tower is very limited.
3o SU 1836534, which shows a modular rig similar to SU 1709059, and with the
same
disadvantages.
Thus there is a great need for an improved modular rig structure in which each
module
has a weight that is less than the lifting capacity of a moderately sized
crane. It is
3a desirable for each module to weigh less than 25 tonnes. Furthermore there
is a need for
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a modular rig structure that may readily be assembled and has an overall
weight that is
small in comparison with conventional rig structures.
The present invention aims to provide a lightweight modular rig structure that
may be
s assembled in a simple manner and has a high degree of applicability. It is
also an object
of the present invention to provide a structure consisting of a limited number
of
modules, in which each module has a limited weight. It is also an object of
the invention
that each module be easy to transport. It is a further object of the invention
to provide a
structure that may be assembled in a very simple and effective manner, and for
which
io the requirement for assembly detail and supports is minimised.
An embodiment of the present invention will be explained in greater detail in
the
following, with reference to the accompanying drawings, in which:
i ~ Figure I shows an exploded view of a rig structure in accordance with the
present
invention;
Figure 2 shows a perspective drawing of a rig structure in accordance with the
present
invention;
zo
Figure 3 shows a first side view of a rig structure in accordance with the
present
invention; and
Figure 4 shows a second side view of a rig structure in accordance with the
present
zs invention.
The exploded view in Figure 1 shows a modular lightweight rig structure 1
according to
the present invention. The structure generally consists of the following
modules: A first
frame module 2 and a second frame module 3, a first lower module assembly 4
and a
o second lower module assembly ~, a first upper module assembly 6 and a second
upper
module assembly 7, a first piping deck 8 and a second piping deck 9, a
drilling deck 10
and a derrick 11.
The frame modules 2 and 3 are designed to be placed on longitudinal sliding
rails 12
3a and 13 that are fixed to the platform deck 15. A BOP deck 14 (BOP = Blow
Out
Preventer) is disposed between frame modules 2 and 3. The BOP 14 deck also
acts as a
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spacer for frame modules 2 and 3, and is connected to these in a manner so as
to fix the
frame modules relative to each other. The frame modules each consist of a base
frame
2a, 3a respectively and two side frames 2b, 2c and 3b, 3c respectively.
> The first and second lower module assembly 4 and 5 consist of a plurality of
single
modules 4a-4d and Sa-Sd respectively, with the case as shown comprising four
single
modules in each module assembly.
The single modules 4a-4d and Sa-Sd respectively are placed side by side,
against each
~o other. The module assembly 4 is designed to be placed inside frame module
2, while the
module assembly 5 is designed to be placed inside frame module 3, on top of
the base
frames 2a and 3a respectively and between the side frames 2b, 2c and 3b, 3c
respectively.
is The first and second module assembly 6 and 7 also consist of a plurality of
single
modules 6a-6d and 7a-7d respectively, with the case as shown also here
comprising four
single modules in each module assembly. The module assemblies 6 and 7 are
designed
to be placed on top of the side frames 2b, 2c and 3b, 3c respectively of the
frame
modules 2 and 3 respectively. Thus the frame modules 2 and 3 respectively
carry the
zo entire weight of the module assemblies 6 and 7 respectively, while the
module
assemblies 4 and 5 carry no weight.
The first piping deck 8 is located on top of the first module assembly 6. The
second
piping deck 9 is located on top of the second module assembly 7. Each piping
deck 8
zs and 9 consists of a base frame 8a and 9a and a plurality of pins 8b and 9b
designed to
retain a respective pipe rack.
A first transverse sliding rail 16 is provided by the edge 8c of the first
piping deck 8,
which edge faces the second piping deck 9. A second transverse sliding rail 17
is
3o provided by the edge 9c of the first piping deck 9, which edge faces the
first piping deck
8. The drilling deck 10 is positioned on sliding rails 16 and 17. The derrick
11 is placed
on top of the drilling deck. On the drilling deck is also provided a control
room 18 and a
module 19 containing among other things a winch and a high-pressure manifold
for
controlling the downhole well pressure.
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Figure 2 shows a perspective view of the modular lightweight rig in the
assembled state.
Here, the longitudinal sliding rails 12 and 13 provided on the platform deck
15 can be
seen. The entire rig may be run slidingly along the sliding rails 12 and 13 by
virtue of
the frame modules 2 and 3 being designed to slide on sliding rails 12 and 13
via siding
blocks 20 on the base frames 2a and 3a. As explained above, the BOP frame 14
forms a
combined spacer and connector for the frame modules 2 and 3, in order for
these not to
be able to move relative to each other.
It is also possible to see the lower module assemblies 4 and 5 placed inside
the frame
o modules 2 and 3, and the remaining module assemblies 6 and 7 located on top
of the
side frames 2b, 2c and 3b, 3c of the frame modules 2 and 3. The module
assemblies 6
and 7 are designed so as to have sufficient load-bearing capacity to be able
to carry the
piping decks 8 and 9, including their respective pipe racks, the drilling deck
10, the
control room 18 and the module 19, and the dernck 11. It is however also
possible to
i s envisage a further frame module being provided on top of each of frame
modules 2 and
3 to house module assemblies 6 and 7.
The drilling rig 10 is designed to be run back and forth along the transverse
sliding rails
16 and 17. For this purpose, the drilling deck is equipped with sliding blocks
21. By
~o running the entire rig along the rails 12 and 13 and the drilling deck 10
including the
derrick 11 along the sliding rails 16 and 17, the derrick may be positioned
over any
point within a defined relevant area.
The frame modules 2 and 3 and the piping decks 8 and 9 may if required consist
of
several submodules in order to reduce the size and weight of the individual
elements to
be transported.
As shown in the figures, the modules 2, 4, 6 and 8 are arranged in a first
column 30, and
the modules 3, 5, 7 and 9 are arranged in a second column 31. A space 32 is
defined
3o between the columns 30 and 31.
Figure 3 shows a side view of the rig according to the invention, along the
direction of
the sliding rails 12 and 13. Here, the first frame module 2 can be seen, which
module
contains the first lower module assembly 4. Furthermore, it is possible to see
the first
upper module assembly 6, which is positioned on top of the frame module 2. The
module assembly 6 is shown as a trussed construction in order to indicate the
fact that it
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is load-bearing. The drilling deck 10 with the derrick 11, the control room 18
and the
module 19 can also be seen. A hoisting winch 22 and a top-drive 23 is also
shown in
detail, in two positions.
s The drilling deck 10 is shown in a first outer position at the extreme right-
hand side of
the drawing, in a solid line. A part of the drilling deck 10 is shown in a
second outer
position at the extreme left-hand side of the drawing, in a broken line.
Figure 4 shows the rig according to the present invention, seen in the
direction across
io sliding rails 12 and 13. Here, the BOP frame 14, the frame modules 2 and 3
containing
the lower module assemblies 4 and 5, the upper module assemblies 6 and 7, the
piping
decks 8 and 9, the drilling deck 10 arranged on sliding rails 16 and 17, the
control room
18, and the derrick 11 may be seen.
Here, one of several skidding cylinders 24 is shown in detail, which cylinder
is
equipped with a gripper 25 and is designed to pull and push the rig along the
sliding
rails 12 and 13.
As can be seen from Figure 4, a large open space is provided between the first
modules
zo 2, 4 and 6 and the second modules 3, S and 7. This large open space leaves
plenty of
space for handling equipment such as the BOP 26 shown.
Figure 4 also shows that the derrick 11 may be modular, consisting of e.g. two
modules
1 la and 1 1b, where module l 1b is to be placed on top of module l la.
z;
The first column 30 may for instance be designed to contain equipment that is
primarily
associated with process activities, while the other column may be designed to
contain
auxiliary and service functions. Furthermore, the first piping deck 8 may
contain a rack
for drill pipes, while the second piping deck 9 may contain a rack for
casings.
The modules will be connected in an appropriate manner by use of assembly
details.
The connecting-up of modules is a technique that is well known to a person
skilled in
the art, and as such does not require a detailed explanation.
