COSL-CS-001 Introduction to Offshore Oil Industry.pdf

It helps to widen your skills in the drilling industries

3. Part 1: Introduction to Offshore Oil Industry
uThe proven reserves of offshore oil are about 38 billion tons；
uOffshore accounts for 34% of the world's total oil resources;
uMore than 50 countries are exploring Oil & Gas in deepwater.
Introduction
Oil & gas distribution of the world
34%
66%
OffshoreOnshore

4. Part 1: Introduction to Offshore Oil Industry
Introduction
Mexico
56 billion barrel
Brazil
>260 billion barrel
Middle west africa
>58 billion barrel
Norway
3.1 billion barrel
Atlantic
u44% of offshore oil resources distribute in deepwater areas.
uIn recent years, oil and gas discoveries in the deep water areas of the Atlantic region are 70% in
all findings.
Deepwater oil and gas operations are the future of oil development!

5. Part 1: Introduction to Offshore Oil Industry
Classification
500m(1640 ft) 1,500m(4921 ft)
Shallow Water Deepwater Ultra Deepwater

6. Part 1: Introduction to Offshore Oil Industry
Characteristics - High Technology Requirements
The Building of Rig Huizhou-21B.
uCompared to onshore drilling, offshore drilling faces subsea challenges, requiring specialized equipment
and more complex technology during the rig building and operation process.
uUnderwater construction is characterized by high technical requirements and high cost.
uSubsea equipment, Subsea wellhead, Conductor casings.

7. Part 1: Introduction to Offshore Oil Industry
Characteristics - Large Investment
HYSY981
uHeight: 136m/447ft
uWeight: 30,000tons
uMaximum operation water depth: 3,000m/9,852ft
uMaximum drilling depth: 10,000m/32,841ft
uTotal investment：1 billion USD
uDaily rental cost: More than 400 KUSD/day

8. Part 1: Introduction to Offshore Oil Industry
Characteristics - High Risk
The BP blowout in Gulf of Mexico in April, 2010:
uRig: Deepwater Horizon (one of the most advanced rigs in
2010)
uTotal investment：350 million USD
uMaximum operation water depth: 3000m/9,852ft
uLocation of the accident: Bloc MC252 in Macondo, GOM
Disastrous Consequence
u11 killed, 17 injured；
u4.9 million barrels’ of oil spilled；
u2,500 Km
2
of water polluted by oil；
uEcological disaster；
uBP was fined $20.8 billion.

9. Part 1: Introduction to Offshore Oil Industry
Oil Development Process
uGeophysical Exploration：to locate the oil and gas.
uDrilling Operation: to establish oil and gas production channels.
uProduction & Processing: to produce and process oil and gas.
Geophysical Exploration
Drilling Operation
stratigraphic section
Cables

10. Part 1: Introduction to Offshore Oil Industry
Oil Development Process
Production & Processing

11. Part 1: Introduction to Offshore Oil Industry
Questions
uWhat is the classifications of shallow water, deepwater or ultra deepwater?
uWhat is the characteristics of offshore oil drilling?
uWhat is the basic oil development process?

12. Part 1: Introduction to Offshore Oil Industry
Questions
uWhat is the classifications of shallow water, deepwater or ultra deepwater?
lShallow water: ＜500m(1640 ft)
lDeepwater: 500-1500m(1640 ft-4921ft)
lUltra deep water: ＞1500m(4921 ft)
uWhat is the characteristics of offshore oil drilling?
lHigh Technology Requirements
lLarge Investment
lHigh Risk
uWhat is the basic oil development process?
lGeophysical Exploration: to locate the oil and gas.
lDrilling Operation: to establish oil and gas production channels.
lProduction & Processing: to produce and process oil and gas.

14. Part 2: Geophysical Exploration
Procedure
1.Send artificial sound
waves underground by
geophysical vessel;
2.Receive and analyze
the reflected waves
from different
formations;
3.Deduce the distribution
of formations;
4.Deduce the distribution
of oil and gas
resources.
Geophysical Exploration
Cymoscope
Hypocenter
Geophysical vessel
Principles of offshore seismic exploration
uGeophysical exploration refers to the research and observation of various geophysical field changes to
detect the formation of lithology, geological structure and other geological conditions.

15. Part 2: Geophysical Exploration
Geophysical Vessel HYSY 720
12×8000m cables
The most advanced and most capable
geophysical exploration ship in Asia
Sound generator
Buoy
Cable
Geophysical Exploration
Seismic ships and long cables towed

16. Part 2: Geophysical Exploration
Geophysical Exploration

18. Part 3: Drilling Operation
Introduction to Drilling
uDrilling operation is the most important measure in the exploration and
development of oil and gas resources.
uWorldwide, drilling accounts for more than 50% of investment in exploration
and field development.
uDrilling operation technical services generally include
•Drilling (Directional Drilling & Measurement / Logging While Drilling)
•Drilling fluid
•Cementing
•Well completion
•Other operations
uClassification of drilling operations
lBy drilling methods: Conventional drilling, special technology drilling
(directional drilling, underbalanced drilling, etc.).
lBy drilling purpose: Exploration well, development well.

19. Part 3: Drilling Operation
Drilling Rig
uDrilling rigs are offshore structures
primarily used to drill Wells.
uRig is equipped with
lDrilling equipment
lPower
lCommunication
lNavigation
lOther equipment (safety and life
saving facilities, personnel living
facilities).
uRig is an indispensable means for
offshore oil and gas exploration and
development.

20. Part 3: Drilling Operation
Drilling rig
Differences between onshore rig and offshore rig
uHow to raise the derrick smoothly above the water.
uHow to withstand the environment of waves.
uHow to link a subsea wellhead at seabed to drilling equipment at rotary table.
Rig onshore Rig offshore
uSubsea equipment
uSubsea wellhead
uConductor casings
1. Rig 2. Conductor 3-5. BOP

21. Part 3: Drilling Operation
Drilling rig
Drilling rig components

22. Part 3: Drilling Operation
Drilling rig
Semi-submersible drilling rigJack-up drilling rigFixed drilling rig
Jacket
Drilling
equipment
Classifications of drilling rig in offshore

23. Part 3: Drilling Operation
Drilling rig
Fixed drilling rig
Jacket
Drilling
equipment
Classifications: 1. Fixed drilling rig
uA device that is fixed on the seabed, with the help
of a pipe frame and cannot move freely.
uThe deck is laid on the platform for the placement
of drilling equipment.
uThe pile legs supporting the fixed platform are
driven directly into the seabed.
uStability of the drilling platform is good, but the
platform cannot move, lead to a high cost.
uFixed drilling rig is seldomly used now.

24. Part 3: Drilling Operation
Drilling rig
Jack-up drilling rig
Classifications: 2. Jack-up drilling rig
uComposed of platform, pile leg, lifting mechanism.
uCan rise and fall along the pile leg, but has no self-navigation ability.
uWhen working,
•Pile legs be lowered into seabed;
•Platform be lifted to a safe working height away from the sea level;
•Pile legs be preloaded to ensure that the platform does not sag during
drilling operations.
uAfter the completion of the well,
•Platform be lowered to the sea level;
•Pile legs be pulled out and lifted, and platform floats to the surface;
•Platform be towed by the tow wheel to the new well position.
uWith the advantages of mobility and reuse, it becomes one of the
most widely used types of drilling rigs.

25. Part 3: Drilling Operation
Drilling rig
uJack-up drilling rig can not work in deepwater drilling.
Classifications: 2. Jack-up drilling rig
Towage of jack-up drilling platform
HYSY 944
Max. working water depth: 122m

26. Part 3: Drilling Operation
Drilling rig
Semi-submersible drilling rigClassifications: 3. Semi-submersible drilling rig
uThe upper part is work deck, the lower parts are two lower
hulls, connected by support columns.
uWhen working, the hull is submerged into water, and the
deck is at a safe height on the water.
uCharacteristics:
•Small water line area, small wave effect, good stability;
•Strong self-sustaining force with anchors;
•Deepwater.
uCompared with jack-up drilling rig,
•Advantages: deepwater for some rigs, flexible
movement;
•Disadvantages: Large investment, high maintenance
costs, need for a complex set of subsea vehicles.

27. Part 3: Drilling Operation
Drilling rig
NANHAI 2
Max. working water depth:
304m/1,000ft
Prospector
Max. working water depth:
1,500m/4,926ft
HYSY 981
Max. working water depth:
3,000m/9,852ft
Classifications: 3. Semi-submersible drilling rig
uSemi-submersible drilling rig can work in deepwater with depths ＞3,000m/9,852ft.

28. Part 3: Drilling Operation
Drilling rig
Classifications: 4. Drilling Ship
uDrilling ship is a floating drilling platform on which
drilling equipment is mounted.
uAdvantages:
•Good mobility;
•Deepwater;
•Strong self-sustaining force;
•Large storage capacity.
Disadvantages:
•Sensitive to waves, poor stability;
•Small deck area;
•Hig cost
WEST AURIGA
uHeight: 228m/749ft
uWeight: 60,554tons
uMaximum operation water depth: 3,600m/12,000ft
uTotal investment：1.24 billion USD
uDaily rent fees: Mote than 500 KUSD/day

29. Part 3: Drilling Operation
Main Operations - 1. Drilling
uDrilling is to penetrate the formation into a certain depth with a number of different casing strings by
using rigs.

30. Part 3: Drilling Operation
Main Operations - 2. Drilling fluid
uDrilling fluid, also known as mud, is a
circulating fluid that can meet the needs of
drilling operation.
uIts main role is to clean the wellbore, balance
formation pressure, transfer the geological
information of the drilled formation to surface,
and break rock hydraulically, etc.

31. Part 3: Drilling Operation
Main Operations - 2. Drilling fluid
ØHole cleaning
Remove the drilled cuttings from the hole & suspend the cuttings when circulation is
stopped.
ØPressure Control
Maintain BHP (hydrostatic Bottom Hole Pressure) greater than formation pressure to
prevent formation fluids from entering the wellbore.
ØCooling & Lubricating
Cool and lubricate the bit and drill pipe.
ØBorehole stability
Improve the borehole stability, prevent the walls of the hole from caving or collapsing.
ØFormation Protecting
Prevent or minimize the damaging effects to the reservoir (chemical and physical
interactions).
ØMudlogging
Assist in the gathering of the information from the formations.
Functions of
Drilling Fluid

32. Part 3: Drilling Operation
Main Operations - 3. Cementing
uCementing is an operation of running casing into the wellbore and
placing working fluid (cement slurry) into the annular space between the
wellbore and casing.
uIt is an key part of the drilling and completion process.
uA conventional cementing job Including two processes: running casing
and pumping cement slurry.
Casing
Cement
Formation
Displacing process of cementing

33. Part 3: Drilling Operation
Main Operations - 3. Cementing
Rig
Mud line
Sea level
Conductor
Surface
casing
Intermediate
casing
cement
Liner
Production casing
uConductor
The first and shortest casing string, serves as a conduit to
raise the circulating drilling fluid high enough to return to
the mud system.
uSurface casing
The second string of casing, serves to case off relatively
shallow unconsolidated formations and aquifers.
uIntermediate casing or intermediate liner
The casing string running between surface casing and
production casing. It usually helps to seal off shallower
producing zones, allowing the operator to drill deeper.
uProduction casing or production liner
Can be the last tubular element cemented in the well. It
creates an annular space with production tubing and
isolates different zones above and within the production
zone.

34. Part 3: Drilling Operation
Main Operations - 3. Cementing
Objectives of Cementing
uIsolate complex formations with collapse or loss, consolidate the drilled hole.
uProvide the basis for the installation of the wellhead device.
uIsolate oil, gas and water layer, prevent channeling of different layers, provide good conditions for the
test and exploitation of oil and gas.
uProtect the fresh water in the upper formation from being contaminated by oil, gas, brine and other fluids
in the deeper formations.
uDuring the development stage, provide good conditions for stimulation operations like acidizing and
fracturing.

35. Part 3: Drilling Operation
Main Operations - 3. Cementing

36. Part 3: Drilling Operation
Main Operations - 3. Cementing

37. Part 3: Drilling Operation
Main Operations - 4. Well Completion
uWell completions is the installation of a downhole pipe and
related equipment so that oil and gas can be efficiently and
safely extracted from a well.
uWell completion refers to everything that takes place in a well
between the end of the drilling process and the moment when a
well is put into production.
uWell completion is the last operation of drilling operation and
the beginning of oil production engineering.
uIt is closely related to oil production, water injection and the
development of the entire oil and gas field.
uThe quality of oil well completion directly affects the production
capacity and economic life of production wells, and even relates
to the reasonable development of the entire oil field.
uThere are three main objectives in the completion process.
lAllow oil or gas into the well so that it can be brought to the surface;
lMinimise water coming into the well or water production;
lMinimise the production of sands.

38. Part 3: Drilling Operation
Main Operations - 4. Well Completion
uDifferent wells reuiqre different completions. Deciding what to do depends on a number of factors,
including:
lsize and shape of the oil reservoir；
lSurroundings of the reservoir;
lTypes of rock and oil.
u Two regular types of well completion methods:
lCased hole completion:
üRun production liner or casing, cemented, perforated.
lOpen-hole completion
üBarefoot completion
üSlotted liner completion
üScreen liner completion
üGravel packed completion

39. Part 3: Drilling Operation
Main Operations - 4. Well Completion
Cased Hole Completion
uCased hole completions, or liner completions, or perforation
completions, is casing or liner run and cemented across the reservoir
zone, then connect the wellbore and reservoir by perforation.
uThe perforation gun shoots through the casing, cement ring
and reservoir into a certain depth in the reservoir to form a
passageway for oil and gas to enter the wellbore.
uIn this operation, perforations are the only passageway for oil
and gas.
Application criteria:
uFractured reservoir.
uReservoirs with gas cap, water drive, aquifer interlayer, and
collapsible interlayer which require to be isolated.
uVarious reservoirs with different properties.
uLow permeability reservoirs requiring large-scale hydraulic
fracturing operations.
Surface casing
Production casing
Cement shealth
Perforated hole
Production zone

40. Part 3: Drilling Operation
Main Operations - 4. Well Completion
Open Hole Completion: 1. Barefoot Completion
A completion method of setting production casing to the top of the production zone, and let the production
zone fully exposed.
Production
casing
Cement
sheath
Surface
casing
Application Criteria:
uFormation Lithology is intact.
uWellbore with no collapse.
uNormally be used in carbonate rock, hard
sandstone, well cemented and relatively
simple horizontal oil layer.
Addvantages:
uLarge exposed area of the production layer.
uSmall resistance of oil and gas flow into the
well.

41. Part 3: Drilling Operation
Main Operations - 4. Well Completion
Open Hole Completion: 2. Slotted liner Completion
uDuring completion, a liner is run into the open-hole, and will pass through the production layer to protect
unstable formation.
uIn the liner, long slits or holes are used to allow oil and gas from the layer to flow to the bottom of the well.
Application Conditions:
uReservoirs without gas cap, water drive, aquifer
interlayer, and collapsible interlayer.
uReservoirs not produced separately with individual
layers and no plan for selective treatments.
uRelatively loose reservoirs, medium coarse
sandstone.
uSingle thick reservoir with homogeneous properties,
or various reservoirs with similar properties.

42. Part 3: Drilling Operation
Main Operations - 4. Well Completion
Open Hole Completion: 3. Gravel Packed Completion
uA completion method in which a specified size and amount of gravel is packed between liner and wellbore.
Application Conditions:
uReservoirs without gas cap, water drive, aquifer interlayer, and
collapsible interlayer.
uReservoirs not produced with individual layers and no plan for
selective treatment.
uRelatively loose reservoirs with serious sanding problem,
medium, coarse and fine sandstone.
uSingle thick reservoir with homogeneous properties, or various
reservoirs with similar properties.
Open hole Gravel Packing

43. Part 3: Drilling Operation
Main Operations - 4. Well Completion
Open Hole Completion: 4. Screen Liner Completion
uScreen liner completions is similar to the slotted liner completion,
a screen liner is run into the open-hole.
uA screen liner is set in the open hole section of the wellbore.
Application Criteria
uThe screen liner completion is used primarily in unconsolidated
formations to prevent the movement of formation
materials(Sands, etc.) into the wellbore, restricting the flow of
reservoir fluids.

44. Part 3: Drilling Operation
Questions
uThe classifications of drilling rigs and their characteristics?
uThe main functions of drilling?
uThe main functions of drilling fluid?
uThe main functions of cementing?
uThe main functions and classifications of well completion?

45. Part 3: Drilling Operation
Questions
uThe classifications of drilling rigs and their characteristics?
lFixed drilling rig
lJack-up drilling rig
lSemi-submersible drilling rig
lDrilling ship
uThe main functions of drilling?
lPenetrate the formation into a certain depth
uThe main functions of drilling fluid?
lHole cleaning
lPressure Control
lBorehole stability
lFormation Protecting
lMudlogging

46. Part 3: Drilling Operation
Questions
uThe main functions of cementing?
lIsolate complex formations with collapse or loss, consolidate the drilled hole.
lProvide the basis for the installation of the wellhead device.
lIsolate oil, gas and water layer, prevent channeling of different layers, provide good conditions for the test and
exploitation of oil and gas.
lProtect the fresh water in the upper formation from being contaminated by oil, gas, brine and other fluids in the
deeper formations.
lDuring the development stage, provide good conditions for stimulation operations like acidizing and fracturing.
uThe main functions and classifications of well completion?
Functions
lAllow oil or gas into the well so that it can be brought to the surface;
lMinimise water coming into the well or water production;
lMinimise the production of sands.
Classifications：
lCased hole completion:
lOpen-hole completion。

48. Part 4: Production & Processing
Introduction
Fixed production process
Wellhead
platform
Production and
processing platform
To land
Oil and gas production refers to
uExtraction of oil and gas from oil and gas reservoirs to surface;
uCollection, transportation, processing, on-site storage;
uMine management in the mining area.
Production & Processing Methods
uFixed Production Platform;
uFloating production storage offloading (FPSO);
uSemi-submersible production, storage and unloading platform.

49. Part 4: Production & Processing
Model 1: Fixed Production Platform
Fixed production process
Wellhead
platform
Production and
processing platform
To land
Production at seaProcessing on land
uCharacteristics:
Production at sea + Processing on land
uApplicable conditions:
lOil field is closer to the coast;
lLarge area, high output of oil;
lPipeline laid under the sea.

50. Part 4: Production & Processing
Model 2: Floating production storage offloading (FPSO)
uCharacteristics:
Production at sea + Processing at sea
uApplicable conditions:
lOil field is far away from coast;
lIn deeperwater.
Wellhead platform FPSO
Mooring tower
FPSO HYSY 118
Max. processing capacity: 9000m
3/day
Production at sea + Processing at sea

51. Part 4: Production & Processing
Model 3: Floating Production Storage Offloading (FPSO)
uCharacteristics:
Subsea Production + Processing at sea
uApplicable criteria:
lOilfield is far away from coast;
lWater depth ＞300m/985ft.
Subsea Production + Processing at sea

52. Part 4: Production & Processing
Model 4: Semi-submersible production, storage and unloading platform
uCharacteristics:
Subsea Production + Processing at sea, better stability
uApplicable conditions:
lOilfield is far away from coast;
lWater depth ＞300m/985ft.
SHENHAI 1(Build in Jun. 2021)
Max. workding water depth: 1500m/4926ft
The world's first 100,000-ton deepwater semi-submersible production, storage and
offloading platform
DEEPWATER 1

53. Part 4: Production & Processing
Questions
uThe main methods of production and processing?
uThe characteristics of each method?

54. Part 4: Production & Processing
Questions
uThe main methods of production and processing?
lFixed Production Platform;
lFloating production storage offloading (FPSO);
lSemi-submersible production, storage and unloading platform.
uThe characteristics of each method?
lFixed Production Platform: Production at sea + Processing on land;
lFloating production storage offloading (FPSO):Production at sea + Processing at sea, Subsea
Production + Processing at sea;
lSemi-submersible production, storage and unloading platform: Subsea Production + Processing at sea.

56. Part 5: Summary
Part 1: Introduction
Offshore Oil
•Importance
•Classification
•Characteristics
•Oil Development Process
•Shallow water: ＜500m
•Deepwater:500-1500m
•Ultra Deepwater: ＞1500m
•Hight technology requiremetns
•Large investment
•High risk
•Geophysical Exploration
•Drilling Operation
•Production & Processing

57. Part 5: Summary
Part 2: Geophysical Exploration
Geophysical
Exploration
•Definition:
•Procedure
•Send artificial sound waves underground by
geophysical vessel;
•Receive and analyze the reflected waves from
different formations;
•Deduce the distribution of formations;
•Deduce the distribution of oil and gas resources.
•Geophysical exploration refers to the research and
observation of various geophysical field changes to
detect the formation of lithology, geological structure and
other geological conditions.

58. Part 5: Summary
Part 3: Drilling Operation
Drilling
Operation
•Introduction: difference of drilling rig between offshore and onshore
•Drilling rig
•Main operations
•Fixed drilling rig
•Jack-up drilling rig
•Semi-submersible drilling rig
•Drilling: Definition
•Drilling fluid: definition, functions
•Cementing: definition, functions
•Well completion:
ØCharacteristics
ØAdvantages
ØDisadvantages
ØSelection in applications
•Cased hole completion
•Open-hole Completion
•Barefoot completion
•Slotted liner completion
•Screen liner completion
•Gravel packed Completion

59. Part 5: Summary
Part 4: Production & Processing
Production
&
Processing
•Definitions:
•Methods
•Fixed Production Platform:
Production at sea + Processing on land
•Floating production storage offloading (FPSO):
Production at sea + Processing at sea
•Semi-submersible production, storage and unloading platform:
Subsea Production + Processing at sea
ØCharacteristics
ØAdvantages
ØDisadvantages
ØSelection in applications