Nautronix NASeBOP Training Course

Capability Presentation
Andrew Connelly
Product Line Manager NASCoM
Subsea Wireless
Communication – Acoustics
SUT 10 Feb 2016
Who We Are
Over 1,700
Proserv is an international energy services
company specialising in the provision of
life-of-field solutions.
Global Footprint:
We have the ingenuity, expertise and proven track record
4 Regions
11 Countries
25 Sites
to look at complex challenges and provide simple, yet
KEY FIGURES
Employees:
outstanding, service-based solutions.
Business Divisions:



Drilling Control Systems
Production Equipment Systems
Subsea Systems & Services
What We Do: Life of Field Services
EXPLORATION & DRILLING
Business Division
Drilling Control
Systems
Production Equipment
Systems
Subsea Systems
& Services
DEVELOPMENT & PRODUCTION
What We Offer
DECOMMISSIONING & ABANDONMENT
Solutions & Services
Operational Assurance
•
•
•
BOP Services
Drilling Control Systems Assurance & Performance
After-market & Lifecycle Management
Production Optimisation
•
•
•
Flow Assurance & Sampling Solutions
Production Control & Safety Solutions
Asset Performance & Operational Integrity
Production Enhancement
& Asset Integrity
•
•
•
•
Greenfield Development
Brownfield Extension, Upgrade & Optimisation
Life-of-field Support
Asset Life Extension
Acoustics Portfolio
NASNet®
NASCoM
NASDrill
NASDive
Survey Services
A comprehensive range
of survey services to the
offshore construction
industry
Acoustic Subsea
Positioning System
Acoustic Command,
Control & Monitoring
Nautronix Acoustic
Subsea Drilling
Advanced Digital Diver
Communications
NASNet® DPR
NASeBOP
NASDrill RS925
-
Acoustic Subsea
Dynamic Positioning
Reference
Acoustic emergency
Blow Out Preventer
NASDrill USBL
Fully digital
hardwired Diver
Communication
-
NASNet® FPR
Acoustic Subsea
Multiplex
Digitally controlled
Through Water
Acoustic
Communication
Acoustic Subsea FPSO
Monitoring
NASMUX™
Introduction to Acoustics
•
The term ‘Acoustics’ or ‘hydro acoustics’ typically relates to any wireless system
which operates underwater using pressure waves to transmit information.
•
A variety of subsea applications utilise acoustics:
–
Control & Monitoring (BOP, AVP...)
–
Data Transfer (Loggers, sensors, AUV...)
–
Positioning (Vessel, ROV, AUV...)
–
Warning Systems (Tsunami)
–
Communications (Divers)
–
Attitude/Altitude Monitoring
–
Imaging (ROV Navigation)
–
Profiling (Bathymetry)
Introduction to Acoustics: Why Use Acoustics?
•
Other forms of underwater wireless exist
–
Light and radio – short range applications.
•
Acoustics – good for long range applications.
•
Lower the frequency the farther the sound will travel
•
–
Some large, low frequency sonar systems can be heard hundreds of miles away.
–
High Frequency allows high resolution imaging or high data rates, but over a short range.
For use in the Oil and Gas industry, we typically only need to span distances of a few
kilometres.
Introduction to Acoustics: Frequency
•
Underwater acoustic equipment will operate at a specific frequency, depending on
the equipment’s purpose:
0KHz
20KHz
Positioning & Data
30Km
10Km
300KHz
Echo
Sounders &
Multibeam
1Km
600KHz
Imaging
Sonars
300m
1.2MHz
Short Range
Echo
Sounders &
Multibeam
100m
Introduction to Acoustics: Signalling for Comms
•
•
Monotonic – basic acoustic systems operate
using single frequency transmissions.
–
Interference
–
Lack of range
Monotonic
Pulse Signal
–
Accuracy
Carrier
Nautronix core technology is ADS2
–
•
Acoustic Digital Spread Spectrum
Broadband signalling technique, resulting in:
–
Improved Accuracy
–
Increased Range
–
Reduced Interference
–
Less power required
Spread Spectrum Signal
Challenges: Doppler
•
Doppler effect changes apparent
frequency of sound from a moving
source
•
Receiver thinks it is hearing a different
frequency
•
–
Bad for traditional acoustics
–
Sounds like different message, or from
different equipment
Modern acoustics detects Doppler
change and corrects
–
Maintain communication with moving
vessel
Challenges: Ray Bending
•
Also known as refraction
•
Variation in speed of sound causes signal to
bend
•
After a certain horizontal distance, it is
impossible to receive anything!
•
Get around by analysis (SVP) and careful
positioning of equipment
–
•
Including above the seabed
Only an issue over many km
Challenges: Multipath
•
Multipath is an effect caused by reflections,
signals taking ‘multiple paths’
•
Multiple signals at the receiver
–
Reflections interfere with the signal
–
Change length of burst
Digital acoustics can cope!
–
Excellent time of arrival detection through
digital coded matched filter correlation
–
Most direct signal
received and decoded,
the rest sounds like
background noise
reflection
reflection
reflection
Bad for traditional acoustics
signal
•
–
Challenges: Velocity of Sound
•
Speed of light ≈ 300,000 km/s
•
Velocity of sound in air ≈ 340 m/s (0.34km/s)
•
Velocity of sound in water ≈ 1500 meters per
second
•
E.g. at 3000m depth, latency is 2 seconds. Round
trip propagation latency is 4 seconds
•
Can you live with data that is 2 seconds old?
–
Yes/no?
–
Depends on the application
Challenges: Noise
•
Ambient noise can obscure incoming signals
•
Noise sources may be natural, such as
marine life, weather, or sea state
•
May be man made, such as thrusters, rotary
tools, construction
•
Signal to noise ratio
•
–
Increase signal power
–
Limit of cavitation
Coding used with digital acoustics improves
ability to detect incoming signals
–
Can even be detected below the ambient
noise floor
–
High reliability, even sitting beside vessel
thrusters
Case Study: Monitoring Multiple Sensors around
Platform Jackets
•
•
•
Challenging for acoustics
–
Lots of noise – equipment, surface
–
Multipath – jackets, seabed, surface
–
Long term deployment – battery life
Solution
–
Digital acoustics – cut through noise, robust in multipath
environment, minimise power consumption through retried
messages
–
Plastic housing and connectors – avoid corrosion issues
–
Power profile – minimise power consumption between reading
sensors
Why Acoustics?
–
Range capability over RF (too shallow for optics)
–
Communicate with all sensor locations from one point, no relay
stations
–
Quicker, and therefore less expensive to deploy
Case Study: Monitoring Multiple Sensors around
Platform Jackets
6
D
E
8
4
5
7
2
1
A
9
B
3
50m
C
x
100m
•
Advantages for customer
–
No ROV needed to recover sensor data
–
Sensor data available much much much more frequently
–
Avoid cables through splash zone
–
Solution good for 5-10 year deployment
Advantages of Acoustics
•
•
•
Wireless!
–
Communicate with equipment without making
physical and electrical connection
–
Communicate with equipment without needing
to get close to it
–
Faster than sending ROV to intervene/retrieve
data
–
Redundant option to wired connections, or
replacement
–
Easily communicate with different
assets/locations
Range
–
Acoustics: km’s
–
Optics: 100 m
–
RF: 10’s m
Considerations
–
Data rate, latency