Analysis into the causes and solutions to noise and vibration on offshore platforms. Analysis and prevention of noise and vibration helps HSE requirements and reduces risk to staff and employee well-being. Services discussed include: > Noise prediction > Outdoor sound propagation studies > Indoor machinery noise analysis > Noise insulation analysis > Vibration studies > Underwater noise studies > Structure-borne noise studies For more information about our services, click here: http://www.lr-ods.com/expertise/noise-and-vibration-control.aspx

1. Lloyd’s Register services to the energy industry
Noise Management in Offshore
Installations
Daniel Alvarez, M.Sc.
Senior Consultant, Energy
Lloyd’s Register
November 11-14, 2014 Adipec

2. Lloyd’s Register services to the energy industry
Noise
•
Source of: stress, high blood pressure, headaches, tiredness,
reduction of work efficiency, hearing loss
•
May be fatal if personnel cannot hear instructions or alarms.
•
Impacts: (1) comfort, (2) working conditions and (3) environment
Offshore Installations
•
Compact environment with large amount of noise and vibration sources
•
Structure-borne noise play an important role in steel-type structures
•
Indoor controlable climate is often required
•
Limited space and weight for noise control measures
•
Movable facilities may want to comply with regulations globally
November 11-14, 2014 Adipec

3. Lloyd’s Register services to the energy industry
Successful Noise Management through...
•
Understanding the targets
•
Dialogue contractors - vendors
•
Find optimal combination of noise control measures
•
All based on Reliable Noise Predictions at early design
stage
Value
•
Substantial reduction of cost
•
Enhance reduction by tailoring control measures to specific
design
•
Minimize risk of expensive retroactive noise control
November 11-14, 2014 Adipec

4. Lloyd’s Register services to the energy industry
Noise Prediction Package often includes...
FWD
11
108-110
10
Shearing Tank
9
98-100
Shearing Tank
6
Noise at indoor machinery areas
5
Triptank Pumps
•
Evaluation of HVAC Noise
•
Vibration studies
•
Underwater noise study
“The matter is not only to operate them,
but to choose the right tool for specific
applications”
November 11-14, 2014 Adipec
94-96
92-94
4
90-92
86-88
84-86
Clean Tank
Centrifuge
Tank
Degasser
Tank
3
2
82-84
80-82
78-80
1
76-78
74-76
0
0
Structure-borne noise study
96-98
88-90
Desilter Pumps
Sand Trap
Tank
Triptank
Noise Insulation Analysis
•
100-102
7
Catch Tank
•
Outdoor sound propagation study
102-104
8
Y (Meter)
•
Vacuum Unit
Desilter Tank
•
106-108
104-106
Slurry Tank
Skimmer Tanks
1
2
3
4
5
6
7
8
9
10
X (Meter)
11
12
13
14
15
16
17
18
72-74
70-72

5. Lloyd’s Register services to the energy industry
Outdoor Sound Propagation Study
•
Focus on working conditions
•
Identifies problem areas and warning signal locations
•
Requires knowledge about oil & gas machinery and
its noise and vibration characteristics (database)
•
Can be used during the entire life cicle for HSE
purposes (requires regular updates)
•
Allows the evaluation of noise control measures
November 11-14, 2014 Adipec

6. Lloyd’s Register services to the energy industry
Noise at Indoor Machinery Areas
•
Focus on working conditions
•
Identifies problem areas and warning signal
locations
•
Requires database of machinery noise and
vibration characteristics as well as indoor
environment properties (Absorption or T60)
November 11-14, 2014 Adipec

7. Lloyd’s Register services to the energy industry
Noise Insulation Analysis
•
Focus on Accommodation Blocks and sensitive areas in noisy environments (control
rooms)
•
Noise transmission from outdoors as well as noise transmission amongst indoor spaces
•
Requires knowledge about material properties (often based on empirical information)
Lp,1
November 11-14, 2014 Adipec
Lp,2 = ?

8. Lloyd’s Register services to the energy industry
Structure-borne Noise Study
•
Focus on Accommodation Blocks
•
Requires source strength (energy to structure)
•
Requires information about how the energy
propagates in the structure (empirical or
statistical)
•
Requires knowledge in regards to material
damping (often flooring)
Lv4
LW4
Lv2 L2W
LW3 Lv3
LW1
Lv1
November 11-14, 2014 Adipec

9. Lloyd’s Register services to the energy industry
Evaluation of HVAC Noise
•
Focus on Accommodation Blocks and often
affecting working conditions too
•
Noise is generated through supply and
return ducting (silencer up and
downstream)
•
Silencers are often cheap solutions but
often forgotten creating a space issue
•
Empirical information about pressure-drop
control devices is often required
November 11-14, 2014 Adipec

10. Lloyd’s Register services to the energy industry
Vibration Studies
•
Deterministic analysis of supporting structure
•
The output refers structural modifications to suit
requirements
•
Often conducted only for major equipment
Excitatio
n points:
November 11-14, 2014 Adipec

11. Lloyd’s Register services to the energy industry
Vibration Studies (2)
•
Coarse evaluation of suporting structure
•
Selection of anti-vibration mounts as per machinery characteristics
•
Database of anti-vibration technology plays an important role
November 11-14, 2014 Adipec

12. Lloyd’s Register services to the energy industry
Underwater Noise Study
•
The effect of piling of offshore platforms
180
10
170
Depth [m]
30
160
50
150
140
70
Seabed
130
90
1
November 11-14, 2014 Adipec
2
4
3
Range [km]
5
6
7
120
Overall SEL (dB re 1µPa2⋅s)
Source

13. Lloyd’s Register services to the energy industry
Underwater Propagation Modelling
Water-filled pile
Water
Water
Acoustic Finite Element Model of untreated
pile vs single-wall cofferdam
Snapshot at 19 ms
Cofferdam
Hammer energy 1890 kNm/kJ
Seabed
Seabed
Pile length/diameter: 45 m / 5.4 m
Water depth: 25 m
Cofferdam: 50 mm steel, 900 mm air
gap
November 11-14, 2014 Adipec

14. Lloyd’s Register services to the energy industry
Conclusions
•
Noise may cause significant costs in your project
•
Noise may generate considerable damage to your employees
•
Theoretical and empirical information in regards to noise and vibration
charateristics of machinery, as well as material noise insulation properties play
an important role during the design
•
Noise and vibration prediction tools help to evaluate your asset. The matter is
not only to operate them, but to choose the right tool for specific applications
•
The earlier noise is considered, the better!
November 11-14, 2014 Adipec

15. November 11-14, 2014 Adipec