OFFSHORE RIG AND PLATFORM Raka S.W., M.T.

OFFSHORE RIG
•Purpose: Primarily used for drilling wells.
•Mobility: Offshore rigs are typically mobile, meaning they can be moved from one
drilling site to another. There are several types of offshore rigs, including:
• Jack-up rigs: These rigs have extendable legs that can be jacked up to provide a stable
platform on the seafloor in shallow waters.
• Semi-submersible rigs: These float on pontoons and are anchored or dynamically positioned,
allowing them to operate in deeper waters.
• Drillships: Ships equipped with drilling rigs, designed for drilling in very deep waters.

•Duration: Offshore rigs are usually temporary, used only during the drilling phase,
after which they move to another location.
•Function: Focuses on drilling exploratory and development wells. Once the wells are
completed, production infrastructure is set up.
OFFSHORE PLATFORM
•Purpose: Used for producing oil and gas after the well is drilled.
•Mobility: Platforms are typically stationary and permanent structures anchored to the seabed
or floating in place. They are not meant to be moved after installation.
•Types: Different types include:
• Fixed platforms: Installed directly on the seabed in shallow to medium-depth waters.
• Compliant towers: Tall, flexible structures used in deeper waters.
• Tension-leg platforms: Floating structures anchored by tensioned cables for deepwater use.
• Spar platforms: Deepwater floating platforms stabilized by a long vertical cylinder (spar).

•Duration: Offshore platforms are permanent and designed to remain in place for the duration
of the field's production life, often lasting decades.
•Function: Used for producing oil and gas, processing, and sometimes even housing personnel.
They are equipped to handle production, storage, and transport of hydrocarbons.
HISTORY OF OFFSHORE DRILLING AND PRODUCTION

Figure A3. Worldwide progression of water depth capabilities for offshore drilling and production
(Courtesy: Wood; Revised by C.V.A.).
DEEP WATER EXPLORATION WELLS
OFFSHORE OIL PLATFORM VS BUILDING
OFFSHORE RIG
How Oil Rig Floats and Works?
https://www.youtube.com/watch?v=F_qeHijQw4s
DRILLING BARGES

Drilling barges are commonly used

for shallow-water inland drilling.
Drilling barges are massive floating
platforms that require tugs to
transport from one location to
another. Canals, lakes, rivers,
marshes, and other bodies of water
are frequent areas for this to occur.
Drilling barges are only suitable for
still, shallow waterways and cannot
survive the water movement found in
vast open sea conditions.
Water Depth: 5 - 50 m
JACKUP DRILLING
PLATFORMS/RIGS
After a jack-up rig is towed to the
drilling location, three or four ‘legs’
are lowered until they land on the
seafloor.

Unlike a floating barge, the working

platform can be raised above the
water’s surface.

Jackup rigs, on the other hand, are

only suitable for shallower seas due to
the impossibility of extending these
legs too far. This rig can only operate
in waters up to 500 feet deep.

These rigs are usually safer to operate

than drilling barges since their working
platform is elevated above the sea
level.
SEMISUBMERSIBLE
Semisubmersible platforms are offshore oil rigs
with floating drill units that incorporates pontoons
and columns that, if flooded, will sink to a
predetermined depth.
By classification, there are three types of
semisubmersibles:
1. ship-shaped semisubmersibles,
2. column-stabilized semisubmersibles and
3. bottle-type semisubmersibles.
These three types of semisubmersibles are
classified by the method of rig submergence in
water.
SEMISUBMERSIBLE
Generally, semisubmersibles are
multi-legged offshore floating
structures consisting of a large deck,
with several legs interconnected at
the bottom underwater with horizontal
buoyant members referred to as
pontoons.
Semi-Submersible may be stationed
using dynamic positioning systems or
anchored using mooring systems.
DRILLSHIPS
Drillships are exactly what they sound like: ships that
are used to conduct drilling operations.

These boats are designed specifically to transport

drilling platforms to deep-sea areas. A typical drillship
will feature a drilling platform and derrick in the
middle of its deck, in addition to all of the other
equipment found on a huge ocean ship.

Drillships also have a hole called a “moonpool” that

runs the length of the ship and down through the hull,
allowing the drill string to extend through the boat and
into the water.

This offshore oil rig is capable of drilling in extremely

deep water. ‘Dynamic positioning’ systems are used by
drillships.
Jack-up Drilling Rig, how does it work - Carlsen Bulk Handling
https://www.youtube.com/watch?v=4oRpR_bbVGs
Poseidon Barge Drilling
https://www.youtube.com/watch?v=xBx85RrjP_w
Marvelous Nepthune (Semi-Submersible Drilling Rig) Petroforia 2019
https://www.youtube.com/watch?v=bdSvZZC-P5g
Overview on Deep Water Drilling
https://www.youtube.com/watch?v=YQtDiX2Dbr0
Huge Drilling Rig Transport | Mega Transports | Free Documentary
https://www.youtube.com/watch?v=43csxMbD5yk
PLATFORMS
Type of offshore platforms - Naval Architecture
https://www.youtube.com/watch?v=RCH-57_SzSE&t=42s
The 5 Largest Offshore Platforms of the World
https://www.youtube.com/watch?v=J2Bykf03fD8
JACKET PLATFORMS
Jacket platforms are simply platforms for
template (jacket) development.
Jacket platforms are used for drilling and
exploration operations.

Offshore Platform Installation- Jacket

Installation

https://www.youtube.com/watch?v=WnwgF
jnWttg
Fixed Platform Installation Project

https://www.youtube.com/watch?v=vPfSX9
4xBOE
CONCRETE GRAVITY-
BASED STRUCTURE
(GBS)
A support structure maintained in place
by gravity is referred to as a “gravity-
based structure,” most prominently
offshore platform.

The basis of construction for the Concrete

Gravity-Based Structure was the
application of reinforced concrete.

The base’s design incorporates vacuum

spaces or caissons to provide the structure
with natural buoyancy, allowing it to be
floated to a field development site.

Once on site, the blank spaces on the

seabed are flooded, and the topside
modules are hauled into place. The
vacant holes were then filled with
permanent iron ore ballast or utilized as
crude oil storage compartments.
Exxon Mobil's Hebron, oil rig gravity based structure
https://www.youtube.com/watch?v=kpp7r5bABv0
Hebron Acting Offshore Platform The Largest and Stunning
https://www.youtube.com/watch?v=tIh-V0q08HY
COMPLIANT TOWERS
(TOWER PLATFORMS)
In contrast to the relatively hard legs of a
permanent platform, the compliant tower is
flexible [241].
Since it can ‘absorb’ most of the pressure placed
on it by the wind and waves, it can function in
much deeper water.
The compliant tower system is sturdy enough to
survive hurricane conditions despite its flexibility.
Compliant towers are utilized in water depths
ranging from 450 to 900 m and are designed to
withstand substantial lateral deflections and
stresses (1500 to 3000 feet).
SPAR PLATFORMS
Spar platforms are among the most often used offshore
platforms.

The acronym SPAR stands for Single Point Anchor Reservoir.

The SPAR platform is an offshore floating platform with a

relatively large draft to diameter ratio (aspect ratio).

Its deep draft made the natural periods outside the wave
ranges thereby attributing to its wide acceptance for

different operational scenarios, especially in deeper

waters.

The Spar platform is the world’s largest oil extraction

platform which can be employed at depths up to 10,000
feet.

This platform is mainly comprised of a massive cylinder

support system and a standard fixed rig platform.
TENSION LEG PLATFORM
(TLP) PLATFORM
The Tension Leg platform is a type of
platforms that is held by tendons.
The platform’s long, flexible legs are
anchored to the seafloor and run up to it.
These legs, allow for a lot of side-to-side
movement (up to 20 feet) but very limited
vertical mobility.
Tension leg platforms are capable of working
at depths of up to 7000 feet.
TLP Animation

https://www.youtube.com/watch?v=Pm9jfrpA
GFo
SEMI-
SUBMERSIBLE
A semi-submersible platform is
a specialised marine vessel used
in offshore roles including as
offshore drilling rigs, safety
vessels, oil production platforms,
and heavy lift cranes. They have
good ship stability and
seakeeping, better than
drillships.[1]
FPSO (FLOATING
PRODUCTION STORAGE
AND OFFLOADING)
The acronym FPSO stands for floating
production storage and offloading.
As the name implies, the FPSO is a
production system equipped with
processing equipment for the
separation and treatment of crude oil
and gas together with a large
storage hull to store the treated oil
for export.
ADVANTAGES AND DISADVANTAGES OF
OFFSHORE PLATFORMS.
ADVANTAGES AND DISADVANTAGES OF OFFSHORE
PLATFORMS.
DESIGN CONSIDERATIONS
 FUNCTION
Common functions:
1. Drilling,
2. producing,
3. storing,
4. materials processing,
5. living quarters
A study of the layouts of equipment to be
located on the decks should be used to decide
the platform configuration.
Before deciding on final dimensions, the
clearances and spacing of equipment should be
carefully considered.
Function determines the classification of the Figure 3 shows the floating drilling barge used in early
offshore structure. explorations in the Gulf of Mexico (GoM), USA.
The function of jack-ups could be for drilling or
decommissioning or the installation of wind
turbines.
LOCATION

Environmental circumstances
vary by location:
1. within a particular
geographic area,
2. foundation conditions,
3. design wave heights,
periods, and tides,
The water depth should be as
precise as is feasible so that
elevations for fenders, decks,
boat landings, and corrosion
protection may be set.
WATER DEPTH,
WAVES AND CURRENT
As seen in Table 2, there are
different variations of
environmental conditions for
both the including oceans,
waves, currents, and weather
conditions around the world.
To choose the right
oceanographic design
parameters, information on sea
depth, ocean waves, current and
tides is required.
 WATER DEPTH, WAVES AND CURRENT
AREA DESIGN CONSIDERATIONS
Gulf of Wave heights: up to 21 m
Mexico (depending on sea depth)
Wind velocities: 170 km/hr
Tides: up to 4 m in shallow
areas
Persian Wave heights: up to 12.2 m
Gulf Wind velocities: up to 130
km/h asTides: up to 3 m
Southern Wave heights: be over 19
Caspian m, while in the North Sea, it
Sea can be over 32 m,
depending on the region

Figure A4. Map of extreme weather, its risks of physical impact by country ranking and sea level rising conditions
globally (Courtesy: Mapsofworld).
 API STANDARD
API STANDARD EXPLANATION
API- 2INT-MET global loads and hurricane weather conditions for use in constructing offshore structures.

API-RP- 2AWSD, design and analyze fixed and floating offshore platforms. The API establishes minimal design
API-RP-2A-WSD, standards for a 100-year design storm.
API RP-2L
API RP-2L Helipads, often known as helicopter landing pads or decks, on offshore
platforms must adhere to.

API RP-2A the lowest deck must have a minimum 1.5 m air gap between the bottom of the deck beams
and the wave crest during the maximum expected level of water, taking into account wave
height and tides, as specified in.
the platform must be able to withstand the loads imposed by the environment, as well as
loadout, transit, and installation loads, as well as other loads imposed by onboard
equipment. See some
REFERENCES
Amaechi, C. V., Reda, A., Butler, H. O., Ja’e, I. A., & An, C. (2022a). Review on fixed
and floating offshore structures. part I: Types of platforms with some applications.
Journal of Marine Science and Engineering, 10(8), 1074.
https://doi.org/10.3390/jmse10081074
Amaechi, C. V., Reda, A., Butler, H. O., Ja’e, I. A., & An, C. (2022). Review on fixed
and floating offshore structures. part II: Sustainable design approaches and project
management. Journal of Marine Science and Engineering, 10(7), 973.
https://doi.org/10.3390/jmse10070973
THANK YOU