EFFECT OF SUBSEA CONDITION MONITORING ON AVAILABILITY OF
SUBSEA EQUIPMENT
Presented by Leong Pei Chze
19 October 2016
OUTLINE
What is Availability?
Typical Subsea Control System Failure
Why Do We Need Condition Monitoring? – Theoretical & Field Case
Studies
Subsea Data Processing and Analysis with Condition Monitoring
Reactive to Proactive Maintenance
Conclusion
2 Effect of Subsea Condition Monitoring on Availability of Subsea Equipment
WHAT IS AVAILABILITY?
Probability that a product is performing it’s intended function over a period of time in a stated operating
condition (fraction of uptime over total operation time).
𝑨𝑽𝑨𝑰𝑳𝑨𝑩𝑰𝑳𝑰𝑻𝒀 = 𝑼𝑷𝑻𝑰𝑴𝑬
𝑼𝑷𝑻𝑰𝑴𝑬 + 𝑫𝑶𝑾𝑵𝑻𝑰𝑴𝑬
3 Effect of Subsea Condition Monitoring on Availability of Subsea Equipment
Operating
Failed
TYPICAL SUBSEA CONTROL SYSTEM FAILURE
4 Effect of Subsea Condition Monitoring on Availability of Subsea Equipment
Approximately 70% of the subsea equipment failures are Controls System related failures:
Field Recorder – subsea performance data collected to form a reliability database and with analysis by the
Condition Monitoring system, converted to useful information that could maximize uptime and efficiency of
the system.
THEORETICAL BASIS: WHY DO WE NEED CONDITION MONITORING?
5
Markov Chain Model: Preventive Maintenance + Condition Monitoring
Working
State
Partial
Failure
Detection
State
Condition-
based
Maintenance
State
Complete
Failure State
Unplanned
Maintenance
State
Regular Preventive
Maintenance
State
Effect of Subsea Condition Monitoring on Availability of Subsea Equipment
THEORETICAL BASIS: WHY DO WE NEED CONDITION MONITORING?
6
Results from Markov Chain Analysis: ~2% Availability Increase!
Effect of Subsea Condition Monitoring on Availability of Subsea Equipment
0.97
0.975
0.98
0.985
0.99
0.995
1
0 1 2 3 4 5 6 7
Time, in years
Availa
bili
ty
Inclusion of Condition
Monitoring
With Condition based
Maintenance, increase of
~2% subsea system
availability!!
With Annual Preventive Maintenance
CONDITION NOTIFICATION
Increased Internal
Pressure Detected in
Subsea Router Module
FIELD CASE STUDY #1: REDUCED DOWNTIME Subsea Router Module Leakage Detection
7 Effect of Subsea Condition Monitoring on Availability of Subsea Equipment
Pump Supply
Pressure
Pump Runtime
Normal Pump
Operation
Identified Pump Run
Abnormalities
Resent valve command - Back
to Normal Pump Operation
FIELD CASE STUDY #2: BETTER DECISION Hydraulic Fluid Leakage Detection
8 Effect of Subsea Condition Monitoring on Availability of Subsea Equipment
FIELD CASE STUDY #3: INCREASED UPTIME Subsea Choke Monitoring
Cv Deviation
Gas Flow Rate
Choke Valve
position
High Cv deviation
detected at initial
setup
Choke Valve Position
is reducing but Gas
Flow Rate is
increasing
9 Effect of Subsea Condition Monitoring on Availability of Subsea Equipment
DATA PROCESSING
10
With Condition Monitoring System
Effect of Subsea Condition Monitoring on Availability of Subsea Equipment
Subsea Power and Communication Unit
(with Topside Processing Unit)
Field Recorder Analysis, Subsea Historian,Knowledge Database
And Presentation Server(Condition Monitoring System)
Remote Monitoring
SUBSEA OFFSHORE ONSHORE REMOTE
Operator Control System/Master Control System
TopsideRelevant
Data
CriticalProduction
Data
Subsea Control System
Converts raw data to measurement of equipment condition, known as Technical Condition
Index (TCI) scaled 0-100%
TCI is calculated for state of an item or the whole assembly, and can be aggregated according
to the operating conditions
SUBSEA DATA ANALYSIS WITH CONDITION MONITORING
11 Effect of Subsea Condition Monitoring on Availability of Subsea Equipment
REACTIVE TO PROACTIVE MAINTENANCE
12 Effect of Subsea Condition Monitoring on Availability of Subsea Equipment
CONCLUSION
Theoretically proven subsea condition monitoring complements preventive maintenance
Field case studies shared to demonstrate subsea condition monitoring benefits:
• Better decisions
• Increased uptime
• Reduced downtime
Subsea condition monitoring system complements the subsea control system - enables
proactive maintenance planning and increasing system availability
Increase system availability by reducing downtime, increasing uptime
13 Effect of Subsea Condition Monitoring on Availability of Subsea Equipment