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Working together for a safer world
Optimising equipment Safety, Operations and Cost performance.
Pieter van Asten - Maintenance, Risk and reliability How technology and innovation drive optimisation AND safety.
Lloyd’s Register Energy
Agenda
• Introduction
• Risk and Reliability modelling
• Key to optimization
• Data quality and quantity
• Reliability model principle
• Application for BOP annular close function
• Application for Mud pump fluid end parts
Lloyd’s Register Energy
Introduction
• Prevention of over / under maintenance of safety and operational critical equipment is often encountered as problematic without loss of performance.
• Combined with cost efficiency of keeping up with safety and operational performance adds an extra layer of complexity to the problem.
• They seem to be conflicting factors.
• A key aspect to this problem is awareness and knowledge about risk exposure involved.
• This presentation will highlight a proven solution to create an optimal balance between cost, NPT and safety.
Lloyd’s Register Energy
Risk and Reliability modelling
• Risk is defined as the probability of failure multiplied by the effect of that failure. • Probability of failure: how often something fails. (Knowing how it fails or what makes it fail is
equally important for effective maintenance = reliability improvement)
• Effects are for example safety, compliance, NPT (pulling a BOP), loss of income, etc
Lloyd’s Register Energy
Risk and Reliability modelling: working in tandem
Operational success (Safety increase / NPT decrease ) is strongly dependent on the reliability of technical equipment and related through risk reduction.
Unsuccesful
performance Major Accident Hazards : Top
Event
Non Productive Time : NPT /
Costs Succesful
performance
Safety
Uptime : Income
Sustained operational and safety performance, addressing NPT root cause and costs:
Safety - NPT reduction
Effective asset management: risk / reliability based information and prioritization of safety and
operational critical components.
Risk reduction
Lloyd’s Register Energy
The key to optimisation
• A reliable system assures safe and efficient operations: lower overall risk exposure. o Reliability can be achieved in either the design or by maintenance that affects equipment
failure.
o Reliability is measured through failure probability
o Reliability affects both safety and operational equipment performance at ‘x’ cost.
o Maintenance can often only being done within a certain (operational-)timeframe.
Reliability management is very suitable to optimise NPT and safety on a cost basis as all are risk aspects and form a perfect balance beam:
cost of the risk of failure vs. the cost of failure prevention.
Lloyd’s Register Energy
The key to optimisation
• Risk and its associated cost are key to optimise between over and / or under maintenance for safety and operational performance.
o Component risk of failure is dependant on the system and its functionality that component operates in.
o Component risk of failure is dependant on the level of redundancy of these components in that system.
o The effect of component failure, expressed in cost, is therefore different for different functionality.
• Lloyd’s Register Energy Reliability model takes these differentiations into account.
Lloyd’s Register Energy
The key to optimisation
• The main focus of Lloyd’s Register Energy’s Reliability model is to assist in cost balance without loss of critical equipment functionality in future operations:
Safe and effective delivery of a well with a focus on cost optimisation.
• The essence of Lloyd’s Register Energy’s Reliability model is the ability to balance cost of the risk failure with the cost of failure prevention.
• Typical statements for our reliability model: “Lacking data quantity or quality is not a reason not to start”
“Is the value of the risk that was prevented equal or higher as the cost of preventing (i.e. maintenance)?”
“Forecasting what needs to be done now to prevent future component failures leading to NPT or unsafe situations”
“Prioritisation of maintenance work that has the highest effect on risk prevention: replacing now or later, what is the effect of replacement or maintenance, on future operations and cost-wise?”
Lloyd’s Register Energy
Data quality and quantity
• Successful application of reliability modelling depends on data quality and quantity. • Improved data quality allows for more accurate reliability calculations, prediction and
decisions. • Data quantity, also from different sources, mixed and matched (time and usage based)
leverage data quality and quantity. • Data quality improves due to focussed data collection upon the start of a reliability
project.
• Data maturing cycle:
Lloyd’s Register Energy
Data quality and quantity: using small data samples
• How does it look like: raw failure data from asset management system.
• Using only corrective maintenance (failure) data leads to a too conservative MTTF.
Lloyd’s Register Energy
Reliability model principle
• Example of reliability model principle (input can be time, usage (i.e. cycles, miles))
Net. expected positive difference on cost of risk:
$ 330 000
Lloyd’s Register Energy
Reliability model
• The optimal effect is achieved when focussing on component failure analysis to optimize functional (reliability) performance and success.
• This allows for demonstration of maintenance effect and cost motivation against operational success or cost of being unsuccessful.
• Combination of functions and components • Optimised component reliability = optimised performance = optimised function =
operational success . • Adding cost of repair, spares and cost of risk of failure
allows for a cost balance: a means to align operations and maintenance departments talking a similar language: less confusion: better decision motivation.
Lloyd’s Register Energy
Reliability model applied for a BOP annular function
• Example of BOP operational usage in 7 scenarios.
Lloyd’s Register Energy
Reliability model applied for a BOP annular function
• Maintenance and Inspection reliability based prioritisation
• Maintenance matrix: risk based urgency
• Maintenance Plan Reliability informed (Reliability – System contribution – Cost) • T5 / 110 days
• T6 / 185 days
• T7 / 210 days
Lloyd’s Register Energy
Reliability model applied for a BOP annular function
How does it look like:
Lloyd’s Register Energy
Reliability model applied for mud pump maintenance
• Mud Pump 1 & 2 • Each mud pump has three cylinders, numbered 1, 2 and 3. • Each cylinder has one piston liner and one piston. • Each cylinder can be configured with a combination of piston and liner of
a specific size. The rig uses 5-inch, 6-inch, and 6½-inch liner diameters. • Two mud pumps need to be used for 12¼ inches holes and larger. • Costs consumables
Component Diameter/type Price [Euro] Note Liners 5” 2200 Ceramic 6” 2160 Ceramic 6.5” 510 Steel Pistons 5” 90 6” 110 6.5” 205 Valves Suction & Discharge 120 Seats Suction & Discharge 85
Lloyd’s Register Energy
Reliability model applied for mud pump maintenance
• Only 1,5 years of data • Different types valves, seat, pistons and liners. • Data sets merged to increase accuracy.
Lloyd’s Register Energy
Reliability model applied for mud pump maintenance
• Preventive replacement because of uninterrupted operation required for both mud pumps (minimum flow requirement 12¼ inch hole):
• Cost of spare parts vs. cost of down time • Figure below assumes a one hour repair • Preventive replacement is cost efficient from a usage of 250 hours.
Lloyd’s Register and variants of it are trading names of Lloyd’s Register Group Limited, its subsidiaries and affiliates. Copyright © Lloyd’s Register Energy Drilling. 2014. A member of the Lloyd’s Register group.
Dr. Gerard Gaal Senior Reliability Consultant Reliability Engineering E gerard.gaal@lr.org
Lloyd’s Register Energy Drilling Gapingseweg 1A, 4353 JA Serooskerke, Netherlands
T +31 118 563 050
Working together for a safer world
Pieter van Asten Senior Concepts manager – Innovation E: pieter.vanasten@lr.org
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