U.S. patent application number 12/278243 was filed with the patent office on 2010-06-17 for offshore oil production platform.
Invention is credited to Renata Anita De Raj, Nagendran C. Nadarajah.
Application Number | 20100150660 12/278243 |
Document ID | / |
Family ID | 38670606 |
Filed Date | 2010-06-17 |
United States Patent
Application |
20100150660 |
Kind Code |
A1 |
Nadarajah; Nagendran C. ; et
al. |
June 17, 2010 |
OFFSHORE OIL PRODUCTION PLATFORM
Abstract
The present invention relates to an offshore oil production
platform. The platform includes a deck (12) and a sub-structure
(10) comprising plurality of ballast chambers (20) and at least one
of connecting leg (16) connected from the ballast chambers (20) to
the deck (12). The ballast chambers (20) include at least one oil
storage compartment (22), at least one ballast compartment (24) and
at least one air pressure compartment (26). The oil and gas storage
compartment (22) is for storing processed oil and gas. During
installation of the platform, the ballast chambers (20) are
ballasted with sea water (46) which allows lowering of the
connecting legs (16) towards the sea bed (34). After the ballast
chambers (20) reach the sea bed (34), locking means is actuated to
a locked position to prevent movement of the sub-structure (10) of
the platform. The deck (12) is moved up to a predetermined height
from sea level by jacking means. After the oil is extracted, it is
then processed and separated to processed oil and gas. The
processed oil and gas are then stored in the oil and gas storage
compartment (22). The oil and gas are then transferred to a buoy
and then loaded to tanker vessels by connecting conduits. During
the de-installation of the oil production platform, the ballast
chambers (20) are de-ballasted whereby the sea water (46) in the
ballast compartment (24) is flushed out. Thus, the sub-structure
(10) of the platform moves upwards to reach the deck (12). When the
base (14) touches the deck (12), the locking means is actuated
thereby locking the sub-structure (10) together with the deck (12).
Finally, the oil production platform is towed to its new
destination for further extraction of oil.
Inventors: |
Nadarajah; Nagendran C.;
(Kuala Lumpur, MY) ; De Raj; Renata Anita; (Kuala
Lumpur, MY) |
Correspondence
Address: |
Workman Nydegger;1000 Eagle Gate Tower
60 East South Temple
Salt Lake City
UT
84111
US
|
Family ID: |
38670606 |
Appl. No.: |
12/278243 |
Filed: |
July 17, 2007 |
PCT Filed: |
July 17, 2007 |
PCT NO: |
PCT/MY07/00049 |
371 Date: |
August 26, 2008 |
Current U.S.
Class: |
405/196 ;
405/210 |
Current CPC
Class: |
E02B 2017/0052 20130101;
E02B 2017/006 20130101; E02B 2017/0047 20130101; E02B 2017/0082
20130101; E02B 17/00 20130101; E02B 17/025 20130101; E02B 17/021
20130101; E02B 2017/0086 20130101; E02B 2017/0069 20130101 |
Class at
Publication: |
405/196 ;
405/210 |
International
Class: |
E02B 17/08 20060101
E02B017/08; E02B 17/02 20060101 E02B017/02; E02D 29/00 20060101
E02D029/00 |
Foreign Application Data
Date |
Code |
Application Number |
Mar 12, 2007 |
MY |
PI 2007 0379 |
Claims
1. An offshore oil production platform, before being installed on
sea bed (34), comprising a deck (12), a base (14) connected to at
least one connecting leg (16) substantially vertical upstanding
from the base (14) to above the deck (12) characterized wherein the
base (14) includes: at least one ballast chamber (20) which is
secured by connecting means to one terminal end region of the at
least one connecting leg (16) wherein the ballast chamber (20)
includes at least one oil and gas storage compartment (22) for
storing processed oil and gas, at least one ballast compartment
(24) to be filled with sea water (46) or air or gas and at least
one air pressure compartment (26) for compressed air or gas.
2. An offshore oil production platform as claimed in claim 1
wherein the ballast compartment (24) is connected to the air
pressure compartment (26) by at least one first valve (28) and at
least one second valve (30) which actuate ballasting and
de-ballasting processes respectively.
3. An offshore oil production platform as claimed in claim 1
wherein the ballast chamber further includes a base (32) to support
the ballast chamber (20) at the sea bed (34).
4. An offshore oil production platform as claimed in claim 1
wherein distal end of the connecting legs (16) is attached to a
metallic frame (18).
5. An offshore oil production platform as claimed in claim 1
wherein the ballast chamber (20) are adapted to be anchored to sea
bed by anchoring means.
6. An offshore oil production platform as claimed in claim 1
wherein the oil platform consists of plurality of ballast chambers
(20) and any one of the ballast chamber (20) is detachable and is
replaceable with another ballast chamber (20).
7. An offshore oil production platform before being installed on
sea bed (34) comprising a deck (38), a base (40) connected to at
least one connecting leg (44) substantially vertical upstanding
from the base (40) to above the deck (38) characterized wherein the
base (40) includes: a) at least one ballast chamber (42) which are
secured by connecting means to terminal end region of the at least
one connecting leg (44) wherein the at least one ballast chamber
(42) has a plurality chambers (48) connected in a circular ring and
each said chamber (48) consists of at least one oil and gas storage
compartment for storing processed oil and gas, at least one ballast
compartment to be filled with sea water (46) or air or gas and at
least one air pressure compartment for compressed air or gas.
8. An offshore oil production platform as claimed in claim 7
wherein the ballast compartment is connected to the air pressure
compartment by at least one first valve and at least one second
valve which actuates ballasting and de-ballasting processes
respectively.
9. An offshore oil production platform as claimed in claim 7
wherein the chamber (48) is detachable from the circular ring and
replaceable with a corresponding chamber (48).
10. An offshore oil production platform as claimed in claim 7
wherein the ballast chamber (42) are adapted to be anchored to sea
bed (34) by anchoring means.
11. A method for installing an offshore oil production platform
towed to an oil extraction destination site wherein the platform
includes a deck (12) with at least one connecting leg (16)
upstanding from a base to above the deck and the base includes at
least one ballast chamber (20) connected to terminal end region of
the at least one connecting leg (16) and wherein the at least one
ballast chamber includes at least one compartment (22) for storing
processed oil, at least one compartment (24) to be filled with sea
water or air or gas (46) and at least one compartment (26) for
compressed air or gas characterized in that the method further
includes: a) unlocking the connecting legs from locked to unlocked
position; b) ballasting the ballast chamber (20) with sea water
(46); c) lowering the at least one connecting leg (16) towards sea
bed (34); d) locking the connecting legs (16) to a locked position
when it reaches the sea bed (34); e) jacking up the deck (12) to a
predetermined length above sea level; f) anchoring the ballast
chamber (20) to the seabed by anchoring means; wherein the
ballasting of the ballast chamber is continued after step (b) until
the ballast chambers reaches the sea bed (34).
12. A method for removing and re-using an offshore oil production
platform after extraction of oil at an oil field destination to a
next oil field destination and wherein the platform includes a deck
(12) with at least one connecting leg (16) upstanding from a base
to the deck and the base includes at least one ballast chamber (20)
connected to terminal end region of the at least one connecting leg
(16) and the at least one ballast chamber (20) is anchored to the
sea bed by anchoring means and wherein the at least one ballast
chamber includes at least one compartment (22) for storing
processed oil, at least one ballast compartment (24) to be filled
with sea water (46) or air or gas and at least one compartment (26)
for compressed air or gas characterized in that the method further
includes: a) actuating locking means at the deck (12) from locked
position to unlocked position; b) jacking down the deck (12) from a
height above sea to reach to sea level; c) releasing anchoring
means from the ballast chamber (20); d) de-ballasting the ballast
chamber (20) in order to move the at least one connecting leg (16)
back up to the deck (12); e) actuating locking means to a locked
position when the at least one connecting leg (16) and ballast
chamber (20) reach to a locked position at the deck (12); f) towing
the oil production platform to the next oil field destination.
13. The use of an offshore oil production platform as claimed in
claim 1 wherein the processed oil and gas stored in the oil and gas
storage compartment (22) is independently transferable to carrier
vessels by means of connecting conduits.
14. The use of an offshore oil production platform as claimed in
claim 7 wherein the processed oil and gas stored in the oil and gas
storage compartment is independently transferable to carrier
vessels by means of connecting conduits.
Description
FIELD OF INVENTION
[0001] The present invention relates to an oil production platform.
More particularly, the invention relates to an offshore oil
production platform which includes a deck extending above the level
of sea and connected to a lower base with connecting legs extending
substantially vertically. The present invention also relates to a
method of installing and de-installing the oil production
platform.
BACKGROUND ART
[0002] Offshore oil production platforms generally include a deck
carrying production equipments necessary for drilling, technical
buildings and crew quarters, storage for storing petroleum products
extracted from offshore oil fields and other requirements for
production of oil and gas. Currently, there is a great interest in
operating offshore oil fields at great depths, from several hundred
meters to thousand meters or more. Therefore, it is not possible at
this depth to use gravity platforms resting on sea bed. At great
depths, semi-submersible platforms can be used which will allow the
platforms to float on the surface of the water and moored by taut
anchor lines.
[0003] The semi-submersible platform comprises of a deck and a
sub-structure of a platform. After the deck and sub-structure of
the platform are constructed, the deck is mounted on the
sub-structure and the resulting combination is launched and towed
to its final installation site. The sub-structure includes a base,
and four columns upstanding from the base and the deck being fixed
to the top of the top end of the columns. When the platform reaches
the destination, the sub-structure is lowered into the water. It is
lowered by using rack and pinion mechanism. This system is also
combined with ballasting of the sub-structure. The lowering of the
base of the sub-structure is stopped at a predetermined depth.
Depending on buoyancy of the sub-structure, the deck is pushed up
to the top of the column using the same rack and pinion mechanism
to a height that provides convenient freeboard between the deck and
the surface of the water. This mechanism has disadvantages as it
needs to ensure exact lateral guidance of the deck as it is raised
to a height above the water level, the reason that it needs to
withstand high vertical loads due to the weight of the deck.
Besides that, this mechanism also leads to an increase of cost and
reliability of the platform.
[0004] Commonly, offshore oil production platforms include deck
carrying drilling equipment and crews quarters. The deck is usually
welded to connecting legs which is also known as jacket or columns
driven into the sea bed. Steel pilings are driven through hollow
corners of the jacket into the sea bed to depths that may exceed
100 ft. These pilings secures the platform to the sea bed and
ensures that the deck withstand forces of winds and waves. The
platform also has well conductors that extend down to drill holes.
Oil and gas are extracted through the well conductors and
transported to the deck for separation process.
[0005] There are various methods to install this kind of platform
at the production site. One method of prior art (U.S. Pat. No.
6,293,734) on installing the platform includes the steps of
floating the platform and towing it to the production site,
lowering the legs or columns until it reaches the sea bed, and
finally raising the deck to a height above the water. This is to
avoid high tide waves. Second prior art (U.S. Pat. No. 6,293,734)
method of installing the platform includes the steps lowering the
connecting legs on sea bed, transporting deck of the platform on a
barge from a construction site and transferring the deck from the
barge to the upper ends of the legs. The deck is generally very
heavy, which cannot be easily transferred from one place to
another. The transferring process is done by placing the barge
between the legs of the platform and the deck is moved from the
barge to the legs by ballasting the barge or by using equipment to
lift the deck. Ballasting is a heavy duty process. Other than
ballasting, the deck can be raised or transferred by means of jacks
but jacks are sensitive to lateral forces.
[0006] Generally, the offshore oil production platform is removed
by means of explosive removal. Torches are used to cut the deck
from the legs (jackets) or columns. Then the deck is lifted and
placed on barge. Sediment or mud is usually found in the lower
section of the pilings below the sea bed. Therefore, the interior
of the pilings needs to be cleared to allow placement of the
explosives charges. Water jets are used to clear out the sediment
or mud. Then the explosives are lowered down to a minimum depth of
15 ft below the sea bed through the hollow pilings. After that, the
deck placed on a barge is moved to a certain distance before the
explosives are detonated. Upon detonation, firstly the pilings and
well conductors are raised using a large crane and then the legs
(jackets) are lifted out of the water. Thereafter, the platform
components are later scrapped at the shore or refurbished for reuse
or returned to the sea as an artificial reef site.
[0007] All the above mentioned platforms have a disadvantage when
the oil in the well is in a depletion stage. Most of the platforms
are not moveable and re-useable at a new oil production site.
Another disadvantage is that the platforms are used for
transporting the extracted oil from the deck through long and
expensive pipelines up to a carrier vessel where the oil is kept in
a storage tank before being loaded onto the carrier vessel. Another
disadvantage of the above mentioned platforms is the method of
installation. Most of the methods mentioned above encounters
problems on lowering the legs and raising the deck up and above the
water. The present invention has an objective of solving
possibilities of having a moveable and reusable oil production
platform at a new production site. The present invention also has
an object of having a method that eliminates the problems faced
during the installation of the oil production platforms. Therefore,
there is a need for an off-shore oil production platform that
solves the above mentioned disadvantages.
[0008] Besides that, using the above mentioned platforms at
marginal oil fields is not economical. Construction, installation
and de-installation of the said platforms at marginal oil fields
will be very expensive compared to the amount of oil and gas
extracted at the marginal fields. Therefore, it is not economically
viable. In addition, construction, installation and de-installation
of the said platforms are considered a heavy duty job. At the
locations where oil and gas reserves are substantial, the oil
extracted and processed is transported through pipelines to the
shore for processing and storage purposes. Thus, this system incurs
further cost on the pipelines too. Therefore, there is a need for
an off-shore oil production platform that operates at marginal oil
fields which also solves high cost problem, installation,
de-installation and also the transportation of the oil to the
storage tanks on shore.
SUMMARY OF THE INVENTION
[0009] The present invention relates to a first preferred
embodiment of an offshore oil production platform being installed
on sea bed comprising a deck, a base connected to at least one
connecting leg substantially vertical upstanding from the base
above the deck wherein the base includes at least one ballast
chamber which is secured by connecting means to terminal end region
of the at least one connecting leg wherein the ballast chamber
includes at least one compartment for storing processed oil and
gas, at least one ballast compartment to be filled with sea water
or air or gas and at least one compartment for compressed air or
gas. The ballast compartment is connected to the air pressure
compartment by at least one first valve and at least one second
valve which actuate ballasting and de-ballasting processes
respectively. Distal end of the at least one connecting leg is
attached to metallic frame. The ballast chamber is adapted to be
anchored to sea bed by anchoring means. The ballast chamber further
includes a base to support the ballast chamber at the sea bed. The
oil platform also consists of plurality of ballast chambers and any
one of the ballast chamber is detachable and is replaceable with
another ballast chamber.
[0010] The present invention relates to second preferred embodiment
of an offshore oil production platform being installed on sea bed
comprising deck, a base connected to at least one connecting leg
substantially vertical upstanding from the base to above the deck
wherein the base includes at least one ballast chamber which is
secured by connecting means to terminal end region of the at least
one connecting leg wherein the at least one ballast chamber has a
plurality of chambers connected in a circular ring and each said
chamber consists of at least one oil and gas storage compartment
for storing processed oil and gas, at least one ballast compartment
to be filled with sea water or air or gas and at least one air
pressure compartment for compressed air or gas. The chamber is
detachable from the circular ring and replaceable with a
corresponding chamber. The ballast compartment is connected to the
air pressure compartment by at least one first valve and at least
one second valve which actuate ballasting and de-ballasting
processes respectively. The ballast chambers are adapted to be
anchored to sea bed by anchoring means. Operation and other
components of the second embodiment are as same as the first
embodiment.
[0011] A method for installing an offshore oil production platform
(first preferred embodiment) towed to an oil extraction destination
site wherein the platform includes a deck with at least one
connecting leg upstanding from a base to above the deck and the
base includes at least one ballast chamber connected to terminal
end region of the at least one connecting leg and wherein the at
least one ballast chamber includes at least one compartment for
storing processed oil, at least one ballast compartment to be
filled with sea water or air or gas and at least one compartment
for compressed air or gas and the method further includes unlocking
the connecting legs from locked to unlocked position, ballasting
the ballast chambers with sea water, lowering the at least one
connecting leg towards sea bed, locking the connecting legs to a
locked position when it reaches the sea bed, jacking up the deck to
a predetermined length above sea level and anchoring the ballast
chambers to the seabed by anchoring means. The ballasting of the
ballast chambers is continued until the ballast chambers reaches
the sea bed. The method for installing the second preferred
embodiment of an offshore oil production platform is as same as the
method for the first embodiment.
[0012] A method for removing and re-using an offshore oil
production platform (first embodiment) after extraction of oil at
an oil field destination to a next oil field destination and
wherein the platform includes a deck with at least one connecting
leg upstanding from a base to the deck and the base includes at
least one ballast chamber connected to terminal end region of the
at least one connecting leg and the ballast chamber is anchored to
the sea bed by anchoring means and wherein the ballast chamber
includes at least one compartment for storing processed oil, at
least one ballast compartment to be filled with sea water or air or
gas and at least one compartment for compressed air or gas. The
method further includes actuating locking means at the deck from
locked position to unlocked position, jacking down the deck from a
height above sea to reach to sea level, releasing anchoring means
from the ballast chambers, de-ballasting the ballast chambers in
order to move the at least one connecting leg back up to the deck,
actuating locking means to a locked position when the at least one
connecting leg and ballast chambers reach to a locked position at
the deck and towing the oil production platform to the next oil
field destination. The processed oil and gas stored in the oil
storage compartment is independently transferable to carrier
vessels by means of connecting conduits. The method for
de-installing the second preferred embodiment of an offshore oil
production platform is as same as the method for the first
embodiment.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] The present invention will be fully understood from the
detailed description given herein below and the accompanying
preferred drawings which are given by way of illustration only, and
thus are not limitative of the present invention, wherein:
[0014] FIG. 1 shows a perspective view of the first preferred
embodiment of an offshore oil production platform before being
towed to an oil extraction destination.
[0015] FIG. 1 (a) shows a perspective view of the first preferred
embodiment of an offshore oil production platform installed at sea
bed.
[0016] FIG. 2 shows a diagrammatic view of the first preferred
embodiment of an offshore oil production platform towed to the oil
extraction destination.
[0017] FIG. 2 (a) shows a diagrammatic view of the sea water
entering the ballast compartment in the ballast chambers and
lowering of the sub-structure of the first embodiment of the
offshore oil production platform during the ballasting process.
[0018] FIG. 2 (b) shows a diagrammatic view of the first embodiment
of the offshore oil production platform being installed at the sea
bed.
[0019] FIG. 2 (c) shows a diagrammatic view of the sea water being
flushed out from the ballast compartment in the ballast chambers of
the first embodiment of the offshore oil production platform during
the de-ballasting process.
[0020] FIG. 2 (d) shows a diagrammatic view of the sub-structure of
the first embodiment of the offshore oil production platform moving
up to the sea level during de-ballasting process be towed to a new
destination.
[0021] FIG. 3 shows a perspective view of a second preferred
embodiment of an offshore oil production platform with one
connecting leg before being towed to an oil extraction
destination.
[0022] FIG. 3(a) shows a diagrammatic view of a second preferred
embodiment of an offshore oil production platform with one
connecting leg being towed to an oil extraction destination.
[0023] FIG. 3(b) shows a diagrammatic view of a second preferred
embodiment of an offshore oil production platform with one
connecting leg being installed on the sea bed.
[0024] FIG. 3(c) shows a perspective view of a second preferred
embodiment of an offshore oil production platform with one
connecting leg being installed on the sea bed.
[0025] FIG. 4 shows a perspective view of a second preferred
embodiment of an offshore oil production platform with at least one
connecting leg before being towed to an oil extraction
destination.
[0026] FIG. 4(a) shows a diagrammatic view of a second preferred
embodiment of an offshore oil production platform with at least one
connecting leg being towed to an oil extraction destination.
[0027] FIG. 4(b) shows a diagrammatic view of a second preferred
embodiment of offshore oil production platform with at least one
connecting leg being installed on the sea bed.
[0028] FIG. 4(c) shows a perspective view of a second preferred
embodiment of an offshore oil production platform with at least one
connecting leg being installed on the sea bed.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0029] A detailed description of preferred embodiments of the
invention is disclosed herein. It should be understood, however,
that the disclosed preferred embodiments are merely exemplary of
the invention, which may be embodied in various forms. Therefore,
the details disclosed herein are not to be interpreted as limiting,
but merely as the basis for the claims and for teaching one skilled
in the art of the invention.
[0030] FIG. 1 is a diagrammatic view illustrating a first preferred
embodiment of an offshore oil production platform before being
towed to an oil extraction destination. The oil production platform
includes a sub-structure (10) and a deck (12). The sub-structure
(10) comprises a base (14) comprising with four ballast chambers
(20.sub.1), (20.sub.2), (20.sub.3), (20.sub.4) connected to one
terminal end region of four connecting legs (columns or jackets)
(16.sub.1), (16.sub.2), (16.sub.3), (16.sub.4) respectively
upstanding from the ballast chambers (20) to above the deck (12).
The ballast chambers (20) connected to the terminal end region of
the connecting legs (16) are placed and secured at bottom of the
deck (12) before being installed at sea bed. Each connecting legs
(16) has a mat (18) attached to its distal ends. The mat (18)
comprises of a steel frame. The mat (18) supports the connecting
legs (16) and prevents the connecting legs (16) and ballast
chambers (20) from sinking below sea bed (34). The ballast chambers
(20) are connected by connecting means to the terminal end region
of each connecting legs (16). The present invention is not
restricted to four ballast chambers (20) and four connecting legs
(16) but to a plurality of ballast chambers (20) plurality of
connecting legs (16). Any one of the ballast chamber (20) is
detachable and replaceable with another ballast chamber (20).
Buoyancy of the platform is not affected because buoyancy of the
other ballast chambers will stabilized the platform. The connecting
means used are known in prior art and will not be described herein.
Generally, the deck (12) includes facilities for drilling oil
purposes, technical buildings, drilling well, wellheads processing
facilities, accommodation quarters and other facilities.
[0031] The ballast chambers (20.sub.1), (20.sub.2), (20.sub.3),
(20.sub.4) include at least one oil/gas storage compartment (22),
at least one air pressure compartment (24) and at least one ballast
compartment (26). The oil/gas storage compartment (22) is for
storing processed extracted oil/gas. Extracted oil from the oil
wells is transported to the deck (12) for separation process. After
that, the oil is transported to the ballast chambers (20) and
stored in the oil/gas storage compartment (22). The ballast
compartment (26) is in between the air pressure compartment (24)
and oil/gas storage compartment (22). There are at least one first
valve (28) placed at the ballast compartment (26) to control sea
water (46) to enter the ballast compartment (26) during ballasting
of the ballast chambers (20). There are also at least one second
valve (30) placed at the ballast compartment (26) to control
compressed air from the air pressure compartment (24) to fill in
the ballast compartment (26) during de-ballasting of the ballast
chambers (20). The air pressure compartment (24) is connected to
compressors at the deck (12) through pipes. The compressed air
monitored through sensors at the ballast chambers (20) and control
room at the deck (12). When there is a need for de-ballasting
process, compressed air will be produced and channeled through the
pipes by the compressors to the air pressure compartment (24).
Besides that, the ballast chambers (20) also have appropriate
sensors to monitor during the ballasting and de-ballasting process.
The ballast chambers (20) also have a base (32) respectively to
support the ballast chambers (20) at the sea bed (34). The ballast
chambers (20.sub.1), (20.sub.2), (20.sub.3), (20.sub.4) are
connected to the four connecting legs (16.sub.1), (16.sub.2),
(16.sub.3), (16.sub.4) respectively by connecting means. The
connecting legs (16.sub.1), (16.sub.2), (16.sub.3), (16.sub.4) can
be made of reinforced concrete or metal. Their function is to
support the deck (12). The connecting legs (16) have square cross
sections, but they may just as easily have circular or triangular
cross sections. The connecting legs (16) can also accommodate
various utilities such as pipes, sensors and cables.
[0032] Method of installing the first preferred embodiment (100) of
an offshore oil production platform described above from its
construction site, i.e. dry dock to its final site in a deep water
oil field will now be described. Firstly, the oil production
platform is constructed at the dry dock wherein the platform
includes a deck (12) with at least one connecting leg (16) and a
base comprising with at least one ballast chamber (20) is connected
to the terminal end region of the at least one connecting leg (16)
upstanding from the at least one ballast chamber (20) to above the
deck (12). The at least one ballast chamber (20) is placed and
secured at bottom of the deck before being installed at the sea bed
(34). The deck (12) and the connecting legs (16) are then locked in
a position by using locking means. The locking means used are made
known in the prior art and will not be described herein. When the
platform is ready to be towed to its destination, the dry dock is
flooded with water. The ballast chambers (20.sub.1), (20.sub.2),
(20.sub.3), (20.sub.4) are then de-ballasted to allow the platform
to float wherein compressed air from the air pressure compartment
(24) is pumped into the ballast compartment (26) thus allowing the
platform to float. The platform is now ready to be towed in deep
water to the oil field. Upon reaching the oil field, the connecting
legs (16) are then released from the locked position and the
ballast chambers (20) is ballasted with sea water (46) wherein
valves (30) in the ballast compartment (26) opens and allowing the
sea water (46) to enter into the ballast compartment (26). The
connecting legs (16) are then lowered towards the sea bed (34) as
the sea water (46) enters the ballast compartment (26). Ballasting
herein means that the ballast compartment (26) in the ballast
chambers (20) are filled with sea water (46) which ensures lowering
of the connecting legs (16). When the base (32) of the ballast
chambers (20) reach the sea bed (34), the ballasting of the ballast
chambers (20) is then stopped. The locking means are actuated to
prevent further movement of the sub-structure relative the deck.
Later, the deck is raised to a height above the sea level by using
jacking means and the platform is ready for oil extraction. Finally
the ballast chambers (20) are then anchored to the sea bed (34) by
anchoring means. The anchoring means used are made known in the
prior art and will not be described herein. The extracted oil is
then transported to the deck for further processing and separation
of the extracted oil. The extracted oil can be separated to
processed oil and gas. After the oil is processed, it is
transported back to the oil/gas storage compartment (22). Then the
oil is transferred to a buoy above the sea by connecting means.
Later, the oil from the buoy can be transferred to tanker vessels.
The method of installing the offshore oil production platform is
illustrated in FIGS. 2, 2(a) and 2(b).
[0033] In the present invention, the first preferred embodiment
(100) of an offshore oil production platform is moveable and
reusable. The method of de-installing the first preferred
embodiment of an offshore oil production platform is described
herein. Firstly, the locking means at the deck (12) is unlocked.
Then, water jets are used to clear out the sediment or mud at the
distal end of the connecting legs (16). The connecting legs (16)
are then released from the locked position. Then the deck (12) is
jacked down from the height above the sea to sea level. Then the
anchoring means are released from the ballast chambers (20). The
ballast chambers (20.sub.1), (20.sub.2), (20.sub.3), (20.sub.4) is
de-ballasted wherein the sea water (46) in the ballast compartment
(26) in the ballast chambers (20) is flushed out by means of
compressed air from the air pressure compartment (24) and allow the
connecting legs (16) to move towards the deck (12) to a locked
position. When the base (14) touches the deck (12), the locking
means is actuated therefore locking the ballast chambers (20) and
the connecting legs (16) together with the deck (12). Finally, the
oil production platform is towed to its new destination for further
extraction of oil. The method of de-installing of the offshore oil
production platform is illustrated in FIGS. 2(c) and 2(d).
[0034] Another second preferred embodiment (200) of an offshore oil
production platform is described herein. The platform includes a
sub-structure (36) and a deck (38). The sub-structure (36)
comprises a base (40) comprising at least one ballast chamber (42),
wherein the at least one ballast chamber (42) has a plurality of
chambers (48) connected in a circular ring with large surface area
connected to one terminal end region of one connecting leg (columns
or jackets) (44) upstanding from the at least one ballast chamber
(42) to above the deck (38). The ballast chambers (42) can be
arranged in a deck depending on size and buoyancy requirement. The
at least one ballast chamber (42) are placed and secured at bottom
of the deck (38) before being installed at the sea bed (34). Each
chamber (48) includes at least one oil/gas storage compartment, at
least one air pressure compartment and at least one ballast
compartment. FIGS. 3, 3(a), 3(b) and 3(c) shows the construction
until installation of the second preferred embodiment (200) of the
offshore oil production platform. Operation, function and other
components of the second preferred embodiment of an offshore oil
production platform is the same as the first preferred embodiment
(100) as mentioned above. The chambers (48) are attachable and
detachable for maintenance and new replacement of chambers and
compartments reasons. While detaching the chambers (48) from the
circular ring or attaching a chamber (48) to the circular ring,
buoyancy of the circular ring of the at least one ballast chamber
(42) is not affected. This is due to other chambers which still
have the sea water (46) in their ballast compartments and large
surface area that allows the platform to still maintain its
position at the sea bed (34). The second embodiment (200) is not
restricted to one connecting leg only but can be varied to more
than one connecting leg. FIG. 4, 4(a), 4(b), 4(c) shows the
construction until installation of the second preferred embodiment
(200) with at least one connecting leg of the offshore oil
production platform. Method of installing and de-installing of the
second preferred embodiment (200) is similar to the method of
installing and de-installing of the first embodiment (100).
[0035] Another third preferred embodiment of an offshore oil
production platform is described herein. The third embodiment
includes a sub-structure and a deck. The sub-structure comprises a
base comprising at least one ballast chamber connected to one
terminal end region of one connecting leg (columns or jackets)
upstanding from the ballast chambers to above the deck. The ballast
chambers are placed and secured at bottom of the deck before being
installed at the sea bed (34). Each of the ballast chambers
includes at least one oil storage compartment, at least one air
pressure compartment and at least one ballast compartment.
Operation, function and other components of the third preferred
embodiment of an offshore oil production platform is same as the
first preferred embodiment (100) as mentioned above. Method of
installing and de-installing of the third preferred embodiment is
similar to the method of installing and de-installing of the first
embodiment (100).
[0036] The objective of this present invention is the use of the
oil production platforms (100) and (200) described above at
marginal oil fields. In addition, the ballast compartments of the
oil production platform are not only used as to support and balance
the platform but use as an oil and gas storage compartment for the
processed oil. The processed oil is thereafter transferred to a
buoy through pipes and then loaded to the tanker vessels. Thus, the
present invention also reduces cost for installing and
de-installing oil production platforms at marginal oil fields. The
present invention is not only restricted to marginal oil fields but
also can be extended to deep sea oil extraction.
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