Kane Ramsey and David Young v3 pdf - Enscope Limited - The layout of compressor stations and optimum...
-
Upload
informa-australia -
Category
Business
-
view
346 -
download
0
description
Transcript of Kane Ramsey and David Young v3 pdf - Enscope Limited - The layout of compressor stations and optimum...
![Page 1: Kane Ramsey and David Young v3 pdf - Enscope Limited - The layout of compressor stations and optimum offsite modularisation vs onsite build to increase construction efficiency](https://reader033.fdocuments.us/reader033/viewer/2022060112/556dcbbbd8b42a78768b4984/html5/thumbnails/1.jpg)
DEVELOPMENT | ENGINEERING | MANAGEMENT | COMPLETIONSDEVELOPMENT | ENGINEERING | MANAGEMENT | COMPLETIONS
1
Selected Lessons Learnt
from the Delivery of Gas
Compressor Stations
30th April 2014
![Page 2: Kane Ramsey and David Young v3 pdf - Enscope Limited - The layout of compressor stations and optimum offsite modularisation vs onsite build to increase construction efficiency](https://reader033.fdocuments.us/reader033/viewer/2022060112/556dcbbbd8b42a78768b4984/html5/thumbnails/2.jpg)
DEVELOPMENT | ENGINEERING | MANAGEMENT | COMPLETIONS
• Observations from our personal experience as both Turnkey EPC Contractors and Owner Representatives
• Each of us have direct experience working in a variety of roles on around 40 compressor stations projects over the past 20 years
• David will touch on some of the engineering and design aspects, particularly modularisation
• Kane will focus more on the commercial side and the consequent affect on the schedule
• What has gone well and what hasn’t gone well
2
Introduction
![Page 3: Kane Ramsey and David Young v3 pdf - Enscope Limited - The layout of compressor stations and optimum offsite modularisation vs onsite build to increase construction efficiency](https://reader033.fdocuments.us/reader033/viewer/2022060112/556dcbbbd8b42a78768b4984/html5/thumbnails/3.jpg)
DEVELOPMENT | ENGINEERING | MANAGEMENT | COMPLETIONS
• Like all resources projects the key objectives in the delivery of compressor stations are;
- lowest cost
- best quality
- shortest timeframe
(safety is a given)
• These objectives are generally not aligned
• We believe that the focus should be on a “lowest cost per TJ compressed” basis
3
Key Objectives
![Page 4: Kane Ramsey and David Young v3 pdf - Enscope Limited - The layout of compressor stations and optimum offsite modularisation vs onsite build to increase construction efficiency](https://reader033.fdocuments.us/reader033/viewer/2022060112/556dcbbbd8b42a78768b4984/html5/thumbnails/4.jpg)
DEVELOPMENT | ENGINEERING | MANAGEMENT | COMPLETIONS
• Decision on Contracting Strategy should be taken early –ideally in the concept development stage
• Factors to be considered include;
- Owner’s appetite for risk
- Schedule objectives
- Capacity of the owner’s team to self-perform
- Bankability requirements
- Company procurement policies
- Existing relationships
- Resource availability
4
Contracting Strategy
![Page 5: Kane Ramsey and David Young v3 pdf - Enscope Limited - The layout of compressor stations and optimum offsite modularisation vs onsite build to increase construction efficiency](https://reader033.fdocuments.us/reader033/viewer/2022060112/556dcbbbd8b42a78768b4984/html5/thumbnails/5.jpg)
DEVELOPMENT | ENGINEERING | MANAGEMENT | COMPLETIONS
• Options available for the owner to consider include;
- tendered engagement of consulting engineers and contractors on a Lump Sum basis
- tendered engagement on a Schedule of Rates orIncentivised basis (risk/reward)
- engagement of a head contractor on a Design and Construct basis – either tendered or sole-sourced
- engagement of a head contractor on a Turnkey EPC basis
- engagement on an EPCM basis
- use of a full project Alliance model
5
Contracting Options
![Page 6: Kane Ramsey and David Young v3 pdf - Enscope Limited - The layout of compressor stations and optimum offsite modularisation vs onsite build to increase construction efficiency](https://reader033.fdocuments.us/reader033/viewer/2022060112/556dcbbbd8b42a78768b4984/html5/thumbnails/6.jpg)
DEVELOPMENT | ENGINEERING | MANAGEMENT | COMPLETIONS
• There are many pro’s and con’s to the contracting model adopted
• Compressor stations are generally not technically complex
• Success factors include;
- don’t reinvent the wheel – standardisation in concept from one project to the next has merit
- early engagement of the contractor
- use contractors that have previously performed
- for contractors the carrot usually works better than the stick
- flexibility in contract model to allow pre-commissioning to start before the construction is finished
6
Contracting Options
(cont.)
![Page 7: Kane Ramsey and David Young v3 pdf - Enscope Limited - The layout of compressor stations and optimum offsite modularisation vs onsite build to increase construction efficiency](https://reader033.fdocuments.us/reader033/viewer/2022060112/556dcbbbd8b42a78768b4984/html5/thumbnails/7.jpg)
DEVELOPMENT | ENGINEERING | MANAGEMENT | COMPLETIONS
• Neither the owner nor the contractor wants to take risk –without suitable compensation
• Risk apportionment workshops prior to contract award are a key success factor
• Establishing possible scenarios and role play can help inform these workshops
• Risk should lay with the party best placed to manage (or mitigate)
• Residual risks should lay with the owner
• Drafting the contract should then follow
7
Balance / Risk
Apportionment
![Page 8: Kane Ramsey and David Young v3 pdf - Enscope Limited - The layout of compressor stations and optimum offsite modularisation vs onsite build to increase construction efficiency](https://reader033.fdocuments.us/reader033/viewer/2022060112/556dcbbbd8b42a78768b4984/html5/thumbnails/8.jpg)
DEVELOPMENT | ENGINEERING | MANAGEMENT | COMPLETIONS
• To the extent possible contracts should be balanced
• AS4900 suite provide a good basis, for example AS4902 (Design and Construct) includes;
- Principal Project Requirements
- Requirement for a “functional” design
- Flexibility allowing a variety of contract models
- Indemnity provisions for both parties
- “Good faith” superintendant
- No payment for unfixed plant
• Ultimately, it is the owner that sets the terms…
8
AS4900 Suite of
Contracts
![Page 9: Kane Ramsey and David Young v3 pdf - Enscope Limited - The layout of compressor stations and optimum offsite modularisation vs onsite build to increase construction efficiency](https://reader033.fdocuments.us/reader033/viewer/2022060112/556dcbbbd8b42a78768b4984/html5/thumbnails/9.jpg)
DEVELOPMENT | ENGINEERING | MANAGEMENT | COMPLETIONS
• Outside cost, time is usually the key project driver
• The contract model selected has a direct bearing on the total time for delivery
• The 3 slides that follow are reasonable for typical midline boost compression with a single GT driven compressor
• NB: civils and earthworks disciplines removed for clarity
9
Typical Delivery
Timeframes
![Page 10: Kane Ramsey and David Young v3 pdf - Enscope Limited - The layout of compressor stations and optimum offsite modularisation vs onsite build to increase construction efficiency](https://reader033.fdocuments.us/reader033/viewer/2022060112/556dcbbbd8b42a78768b4984/html5/thumbnails/10.jpg)
DEVELOPMENT | ENGINEERING | MANAGEMENT | COMPLETIONS
• Total delivery period of ~24 months
10
Traditional Sequential /
Tendered approach
FID
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 MONTHS
FEED
Detailed Design
Place Order for Compressor(s)
Compressor Manufacture and Delivery
Other Long Lead Equipment Procurement
Compile Construction ITT
Completion of Detailed Design
Tender Period
Negotiate and Award to Successful Contractor
Construction Contractor Project Team Establishment
Offsite Piping Fabrication
Arrival of Compressors on site
Arrival of Remaining Long Lead Equipment on Site
Mechanical and Piping Installation
Electrical / Instrument Installation
Construction Contractor Practical Completion
Precommissioning
Gas Commissioning
Pip
eA
va
ila
ble
Co
mp
re
sso
rs
Ava
ila
ble
Pra
ctic
alC
om
ple
tio
n
Re
ad
ine
ss
for O
pe
ra
tio
nTRADITIONAL SEQUENTIAL DELIVERY WITH COMPETITIVE TENDER APPROACH
![Page 11: Kane Ramsey and David Young v3 pdf - Enscope Limited - The layout of compressor stations and optimum offsite modularisation vs onsite build to increase construction efficiency](https://reader033.fdocuments.us/reader033/viewer/2022060112/556dcbbbd8b42a78768b4984/html5/thumbnails/11.jpg)
DEVELOPMENT | ENGINEERING | MANAGEMENT | COMPLETIONS
• Total delivery period of ~21 months
11
FID
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 MONTHS
FEED
Detailed Design
Place Order for Compressor(s)
Compressor Manufacture and Delivery
Other Long Lead Equipment Procurement
Compile Construction Scope of Work / Engagement terms
Completion of Detailed Design
Contractor Pricing and Finalisation of Target Price
Construction Contractor Project Team Establishment
Offsite Piping Fabrication
Arrival of Compressors on site
Arrival of Remaining Long Lead Equipment on Site
Mechanical and Piping Installation
Electrical / Instrument Installation
Construction Contractor Practical Completion
Precommissioning
Gas Commissioning
Pip
eA
va
ila
ble
Co
mp
ress
ors
Ava
ila
ble
Pra
cti
ca
lC
om
ple
tio
n
Re
ad
ine
ssfo
r O
pe
rati
onSOLE SOURCE TARGET PRICE / INCENTIVE APPROACH
Sole Source Target
Price approach
![Page 12: Kane Ramsey and David Young v3 pdf - Enscope Limited - The layout of compressor stations and optimum offsite modularisation vs onsite build to increase construction efficiency](https://reader033.fdocuments.us/reader033/viewer/2022060112/556dcbbbd8b42a78768b4984/html5/thumbnails/12.jpg)
DEVELOPMENT | ENGINEERING | MANAGEMENT | COMPLETIONS
• Total delivery period of ~19 months
12
FID
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 MONTHS
Design and Construct Contractor Selected Prior to FID
FEED
Detailed Design
Place Order for Compressor(s)
Compressor Manufacture and Delivery
Other Long Lead Equipment Procurement
Completion of Detailed Design
Offsite Piping Fabrication
Arrival of Compressors on site
Arrival of Remaining Long Lead Equipment on Site
Mechanical and Piping Installation
Electrical / Instrument Installation
Construction Contractor Practical Completion
Precommissioning
Gas Commissioning
Pip
eA
va
ila
ble
Co
mp
re
sso
rs
Ava
ila
ble
Me
ch
an
ica
l C
om
ple
tio
n
Re
ad
ine
ss
for O
pe
ra
tio
nDESIGN AND CONSTRUCT APPROACH, CONTRACTOR SELECTED PRIOR TO FID
Design and Construct
approach
![Page 13: Kane Ramsey and David Young v3 pdf - Enscope Limited - The layout of compressor stations and optimum offsite modularisation vs onsite build to increase construction efficiency](https://reader033.fdocuments.us/reader033/viewer/2022060112/556dcbbbd8b42a78768b4984/html5/thumbnails/13.jpg)
DEVELOPMENT | ENGINEERING | MANAGEMENT | COMPLETIONS
A few selected observations;
• Project success comes down to the people not the logo
• There is a propensity to under-resource project teams
• Engineering leading into procurement tends to drive the schedule more than any other single factor
• Compressor delivery is rarely the critical path
• The receipt date of vendor data can be overlooked
• Valve delivery is nearly always a problem
… and lastly – projects tend to go well when the contractor makes a reasonable profit.
13
Other Observations
![Page 14: Kane Ramsey and David Young v3 pdf - Enscope Limited - The layout of compressor stations and optimum offsite modularisation vs onsite build to increase construction efficiency](https://reader033.fdocuments.us/reader033/viewer/2022060112/556dcbbbd8b42a78768b4984/html5/thumbnails/14.jpg)
DEVELOPMENT | ENGINEERING | MANAGEMENT | COMPLETIONS
• Modularisation of compressor stations can be done in many ways and to varying degrees generally with the goal of reducing the overall project cost and delivery time.
• Typically the mechanism by which the savings are generated is by reducing the number of the high cost and lower efficiency site hours and transferring a large proportion of these hours to a low cost, highly efficient workshop (locally or overseas).
• In our experience the success of this modularisation process to meet the reduction in cost and time goals varies depending on the characteristic of the individual project and the manner in which the modularisation is executed.
• We will look at 3 different types of Modularisation and assess there benefits for use in the delivery of Compressor Station Projects.
14
Modularisation
![Page 15: Kane Ramsey and David Young v3 pdf - Enscope Limited - The layout of compressor stations and optimum offsite modularisation vs onsite build to increase construction efficiency](https://reader033.fdocuments.us/reader033/viewer/2022060112/556dcbbbd8b42a78768b4984/html5/thumbnails/15.jpg)
DEVELOPMENT | ENGINEERING | MANAGEMENT | COMPLETIONS
• Large Module for LNG Storage Facility Boil Off Gas (BOG) compressor. Made Overseas and barged in. Weighs ~ 1,500 tons
• Structural fabrication and Piping fabrication, PWHT, NDT, hydro testing surface treatment, final assembly and Instrumentation hook-up is completed offsite.
15
Large Modules
BOG COMPRESSOR BUILDING
BOG COMPRESSOR MODULE
![Page 16: Kane Ramsey and David Young v3 pdf - Enscope Limited - The layout of compressor stations and optimum offsite modularisation vs onsite build to increase construction efficiency](https://reader033.fdocuments.us/reader033/viewer/2022060112/556dcbbbd8b42a78768b4984/html5/thumbnails/16.jpg)
DEVELOPMENT | ENGINEERING | MANAGEMENT | COMPLETIONS
16
Large Modules
![Page 17: Kane Ramsey and David Young v3 pdf - Enscope Limited - The layout of compressor stations and optimum offsite modularisation vs onsite build to increase construction efficiency](https://reader033.fdocuments.us/reader033/viewer/2022060112/556dcbbbd8b42a78768b4984/html5/thumbnails/17.jpg)
DEVELOPMENT | ENGINEERING | MANAGEMENT | COMPLETIONS
• “Skids” are generally designed and manufactured to fit on a road transportable truck (say 2.4m -4.5m wide) and weight between 5-50 tons (single lift). Some do go up to 150T.
• Structural fabrication and Piping fabrication, PWHT, NDT, hydro testing surface treatment, final assembly and E&I hook-up (to on-skid JB) is completed offsite to maximise work shop hours and reduce site hours.
17
Skids
TYPICAL METERING SKID
![Page 18: Kane Ramsey and David Young v3 pdf - Enscope Limited - The layout of compressor stations and optimum offsite modularisation vs onsite build to increase construction efficiency](https://reader033.fdocuments.us/reader033/viewer/2022060112/556dcbbbd8b42a78768b4984/html5/thumbnails/18.jpg)
DEVELOPMENT | ENGINEERING | MANAGEMENT | COMPLETIONS
18
TYPICAL FUEL GAS SKID
Skids
![Page 19: Kane Ramsey and David Young v3 pdf - Enscope Limited - The layout of compressor stations and optimum offsite modularisation vs onsite build to increase construction efficiency](https://reader033.fdocuments.us/reader033/viewer/2022060112/556dcbbbd8b42a78768b4984/html5/thumbnails/19.jpg)
DEVELOPMENT | ENGINEERING | MANAGEMENT | COMPLETIONS
Piping and Support fabrication, PWHT, NDT, hydro testing and surface treatment is completed of site with support installation, final bolt-up and electrical hook up completed at site. Reduces or removes the requirement for site fit and weld, PWHT, NDT, Hyro-testing and painting. 19
Complete Offsite Fabrication
![Page 20: Kane Ramsey and David Young v3 pdf - Enscope Limited - The layout of compressor stations and optimum offsite modularisation vs onsite build to increase construction efficiency](https://reader033.fdocuments.us/reader033/viewer/2022060112/556dcbbbd8b42a78768b4984/html5/thumbnails/20.jpg)
DEVELOPMENT | ENGINEERING | MANAGEMENT | COMPLETIONS
20
Can be used very effectively for brownfields work, especially when used in conjunction with laser scanning for tie-ins.
Complete Offsite Fabrication
![Page 21: Kane Ramsey and David Young v3 pdf - Enscope Limited - The layout of compressor stations and optimum offsite modularisation vs onsite build to increase construction efficiency](https://reader033.fdocuments.us/reader033/viewer/2022060112/556dcbbbd8b42a78768b4984/html5/thumbnails/21.jpg)
DEVELOPMENT | ENGINEERING | MANAGEMENT | COMPLETIONS
21
Complete Offsite Fabrication
![Page 22: Kane Ramsey and David Young v3 pdf - Enscope Limited - The layout of compressor stations and optimum offsite modularisation vs onsite build to increase construction efficiency](https://reader033.fdocuments.us/reader033/viewer/2022060112/556dcbbbd8b42a78768b4984/html5/thumbnails/22.jpg)
DEVELOPMENT | ENGINEERING | MANAGEMENT | COMPLETIONS
Modularisation
Experiences
• Our experience of modularisation for compressor stations has seen mixed results. Projects these days seem to have tighter schedules and limited budgets (as a result of higher costs).
• Orders are often placed late, vendor data comes in late, designs then run late, equipment arrives late, so modules often get shipped late or in an incomplete state.
• This results in an erosion of the potential savings from modularisation.
• Often the additional cost in added design and increase in structural steel is greater that the savings in marginal labour cost between the workshop and site.
• To many COW’s in the BOG!!
22
![Page 23: Kane Ramsey and David Young v3 pdf - Enscope Limited - The layout of compressor stations and optimum offsite modularisation vs onsite build to increase construction efficiency](https://reader033.fdocuments.us/reader033/viewer/2022060112/556dcbbbd8b42a78768b4984/html5/thumbnails/23.jpg)
DEVELOPMENT | ENGINEERING | MANAGEMENT | COMPLETIONS
Modularisation
Summary
• We do not believe that large scale modularisation provides a cost effective or timely solution for compressor station design and construction.
• Small to medium sized “skids” can provide a cost effective solution for compressors station particularly if there is a standardised design with known vendor information to allow early commencement of fabrication.
• The use of complete offsite fabrication with the majority of all the Welding, PWHT, NDT, Hydro and Surface treatment being completed in the workshop, can provide a very cost effective solution for compressor station construction especially for brown fields work when combined with laser scanning to provide accurate fabrication dimensions.
23
![Page 24: Kane Ramsey and David Young v3 pdf - Enscope Limited - The layout of compressor stations and optimum offsite modularisation vs onsite build to increase construction efficiency](https://reader033.fdocuments.us/reader033/viewer/2022060112/556dcbbbd8b42a78768b4984/html5/thumbnails/24.jpg)
DEVELOPMENT | ENGINEERING | MANAGEMENT | COMPLETIONS
• Consider a 500km free flow pipeline
• Front end compression to 14 MPag
• Delivery at 8 MPag Assume Free flow capacity of 250 TJ/d
• Simple pipeline pressure profile
24
Parallel vs Series
• Selecting Parallel or Series configuration for your midline compressor station is an important decision to be made early in a projects life to ensure the design best meets the facilities functional requirements.
500250
![Page 25: Kane Ramsey and David Young v3 pdf - Enscope Limited - The layout of compressor stations and optimum offsite modularisation vs onsite build to increase construction efficiency](https://reader033.fdocuments.us/reader033/viewer/2022060112/556dcbbbd8b42a78768b4984/html5/thumbnails/25.jpg)
DEVELOPMENT | ENGINEERING | MANAGEMENT | COMPLETIONS
• Expansion required from ~250 TJ/d to ~300 TJ/d
• Install mid-line compressor station with a single compressor unit or 2 units operating in duty and standby.
• Pipeline pressure profile shows a typical ‘sawtooth’.
• Compressor station suction pressure being drawn down, discharge pressure increases above free flow pressure
25
500250
Parallel vs Series
![Page 26: Kane Ramsey and David Young v3 pdf - Enscope Limited - The layout of compressor stations and optimum offsite modularisation vs onsite build to increase construction efficiency](https://reader033.fdocuments.us/reader033/viewer/2022060112/556dcbbbd8b42a78768b4984/html5/thumbnails/26.jpg)
DEVELOPMENT | ENGINEERING | MANAGEMENT | COMPLETIONS
• Single unit operation
• The compressor wheeling or staging is selected to optimise efficiency at normal Operating Condition
• Suitable surge margin is achieved
26
Single Unit
78%
80%76%
74%
Surge control line
Area of choke flow or stonewall
Surge
500250
Parallel vs Series
![Page 27: Kane Ramsey and David Young v3 pdf - Enscope Limited - The layout of compressor stations and optimum offsite modularisation vs onsite build to increase construction efficiency](https://reader033.fdocuments.us/reader033/viewer/2022060112/556dcbbbd8b42a78768b4984/html5/thumbnails/27.jpg)
DEVELOPMENT | ENGINEERING | MANAGEMENT | COMPLETIONS
• Simplified midline centrifugal compressor station configuration (valves removed).
• Pig Launcher and Receiver
• Suction scrubber/ filter/coalescer
• Compressor
• Aftercooler
• Anti surge and cooled recycle
27
Parallel vs Series
![Page 28: Kane Ramsey and David Young v3 pdf - Enscope Limited - The layout of compressor stations and optimum offsite modularisation vs onsite build to increase construction efficiency](https://reader033.fdocuments.us/reader033/viewer/2022060112/556dcbbbd8b42a78768b4984/html5/thumbnails/28.jpg)
DEVELOPMENT | ENGINEERING | MANAGEMENT | COMPLETIONS
• If further expansion is required from ~300 TJ/d to ~350 TJ/d
• Most cost effective option maybe to install a second compressor at the existing midline compressor station
• Pipeline ‘sawtooth’ shows compressor station suction pressure being FURTHER drawn down, discharge pressure increases above SINGLE UNIT pressure
28
500250
Parallel vs Series
![Page 29: Kane Ramsey and David Young v3 pdf - Enscope Limited - The layout of compressor stations and optimum offsite modularisation vs onsite build to increase construction efficiency](https://reader033.fdocuments.us/reader033/viewer/2022060112/556dcbbbd8b42a78768b4984/html5/thumbnails/29.jpg)
DEVELOPMENT | ENGINEERING | MANAGEMENT | COMPLETIONS
• Should the second unit be installed in SERIES with the existing unit or in PARALLEL?
• SINGLE unit typical configuration
29
Parallel vs Series
![Page 30: Kane Ramsey and David Young v3 pdf - Enscope Limited - The layout of compressor stations and optimum offsite modularisation vs onsite build to increase construction efficiency](https://reader033.fdocuments.us/reader033/viewer/2022060112/556dcbbbd8b42a78768b4984/html5/thumbnails/30.jpg)
DEVELOPMENT | ENGINEERING | MANAGEMENT | COMPLETIONS
• TWO units in PARALLEL-typical configuration
• Common Suction Header and a common Discharge Header.
• Units see the same suction and discharge pressure
30
Parallel vs Series
![Page 31: Kane Ramsey and David Young v3 pdf - Enscope Limited - The layout of compressor stations and optimum offsite modularisation vs onsite build to increase construction efficiency](https://reader033.fdocuments.us/reader033/viewer/2022060112/556dcbbbd8b42a78768b4984/html5/thumbnails/31.jpg)
DEVELOPMENT | ENGINEERING | MANAGEMENT | COMPLETIONS
• TWO units in SERIES-typical configuration
• Discharge of the upstream compressor delivers into the suction of the down stream compressor
• Let’s consider the compressor wheelmaps for parallel vs series operation
31
Parallel vs Series
![Page 32: Kane Ramsey and David Young v3 pdf - Enscope Limited - The layout of compressor stations and optimum offsite modularisation vs onsite build to increase construction efficiency](https://reader033.fdocuments.us/reader033/viewer/2022060112/556dcbbbd8b42a78768b4984/html5/thumbnails/32.jpg)
DEVELOPMENT | ENGINEERING | MANAGEMENT | COMPLETIONS
• Initial configuration (single unit operation) operating point is located at optimal efficiency point on wheelmap
• Two units in PARALLEL means less flow per unit but higher head
• If the original wheeling is used for the new PARALLEL configuration, each unit will likely end up operating near surge and may require continuous recycle
• This would result in inefficient operation as power is consumed to recycle gas and we are no longer operating in the highest efficiency envelope on the wheelmap.
32
Original Single Unit
Actual Point
Recycle required
Required Point
Surge
Parallel
![Page 33: Kane Ramsey and David Young v3 pdf - Enscope Limited - The layout of compressor stations and optimum offsite modularisation vs onsite build to increase construction efficiency](https://reader033.fdocuments.us/reader033/viewer/2022060112/556dcbbbd8b42a78768b4984/html5/thumbnails/33.jpg)
DEVELOPMENT | ENGINEERING | MANAGEMENT | COMPLETIONS
• Continuous recycle is a poor outcome so the existing unit would likely need to be rewheeledor restaged.
• The new units wheeling or staging would be selected for optimum efficiency for 2 units operating in PARALLEL (lower flow, higher head)
• The issue now is that if the lower flow rate of 300TJ is required, the new unit or the existing re-wheeled unit are operating at a lower efficiency close to choke flow.
33
Original Single Unit
No re wheel recycle
2 unit parallel operating point
New Wheel map
Parallel
![Page 34: Kane Ramsey and David Young v3 pdf - Enscope Limited - The layout of compressor stations and optimum offsite modularisation vs onsite build to increase construction efficiency](https://reader033.fdocuments.us/reader033/viewer/2022060112/556dcbbbd8b42a78768b4984/html5/thumbnails/34.jpg)
DEVELOPMENT | ENGINEERING | MANAGEMENT | COMPLETIONS
• Two units in SERIES means less head across and more mass flow through each of the units.
• In SERIES configuration, the existing wheelmap may provide a suitable compressor selection for the upgraded operating conditions.
• Avoids the need to rewheel the existing unit as both units operate at close to there highest efficiency envelope
• Both units can be operated efficiently as a single unit if a lower flow rate is required.
• It is recommended that the original unit should be the installed as the down stream unit as this is likely to see less change in the operating point.
• So where is the downside? Stopping a Unit!
34
Original Single Unit
Upstream Unit
Down Stream Unit
Series
![Page 35: Kane Ramsey and David Young v3 pdf - Enscope Limited - The layout of compressor stations and optimum offsite modularisation vs onsite build to increase construction efficiency](https://reader033.fdocuments.us/reader033/viewer/2022060112/556dcbbbd8b42a78768b4984/html5/thumbnails/35.jpg)
DEVELOPMENT | ENGINEERING | MANAGEMENT | COMPLETIONS
• Let’s consider what happens when both compressors are operating in PARALELL with our new optimised wheel map
• What happens to the operating unit when the other unit has a FAST STOP/trip or is taken off load?
• Initially the operating unit still sees the same suction pressure and delivers the same head. The flow through the station will effectively be halved.
• Over time, the discharge pressure will reduce as the second unit is no longer assisting and the single operating unit will deliver more flow but at a reduced head.
• No upset conditions created due to a single unit tripping or being taken off load
35
2 Units in Parallel
Original Single Unit
Single operating unit after trip
Parallel vs Series
![Page 36: Kane Ramsey and David Young v3 pdf - Enscope Limited - The layout of compressor stations and optimum offsite modularisation vs onsite build to increase construction efficiency](https://reader033.fdocuments.us/reader033/viewer/2022060112/556dcbbbd8b42a78768b4984/html5/thumbnails/36.jpg)
DEVELOPMENT | ENGINEERING | MANAGEMENT | COMPLETIONS
• Compressors operating in SERIES
• What happens to the operating unit when the other unit has a FAST STOP or is taken off load?
• Immediately, the operating unit sees a large increase in head across the compressor
• A unit stopping has created a potential surge event on the operating unit
• The station will go into recycle (and flow may completely stop) until the head washes out and the single compressor can generate enough head to create station flow.
36
Unit in Series
Compressor instantly moves towards surge
Single operating unit after trip
Required point after trip
Parallel vs Series
• Operating units in Series should include design measures to actively protect the units from these trips and the resultant potential surge events.
• Surge margin equalisation and load sharing is recommended for both series and parallel operation.
![Page 37: Kane Ramsey and David Young v3 pdf - Enscope Limited - The layout of compressor stations and optimum offsite modularisation vs onsite build to increase construction efficiency](https://reader033.fdocuments.us/reader033/viewer/2022060112/556dcbbbd8b42a78768b4984/html5/thumbnails/37.jpg)
DEVELOPMENT | ENGINEERING | MANAGEMENT | COMPLETIONS
37
• In most application including upstream or front of line Compressor Stations Parallel configuration is likely to be the best option.
• For midline compressor stations which experience very little variance in pipeline flow and where the fully compressed pipeline design only has one operating unit (ie duty/standby) parallel configuration will likely be the best option.
• However, for midline compressor station with variable pipeline demand and where the fully compressed pipeline design has multiple units operating at each compressor station configuring your compressors in series should be considered.
Parallel vs Series
Summary
![Page 38: Kane Ramsey and David Young v3 pdf - Enscope Limited - The layout of compressor stations and optimum offsite modularisation vs onsite build to increase construction efficiency](https://reader033.fdocuments.us/reader033/viewer/2022060112/556dcbbbd8b42a78768b4984/html5/thumbnails/38.jpg)
DEVELOPMENT | ENGINEERING | MANAGEMENT | COMPLETIONS
• Unit Aftercoolers- has a single set of coolers per compressor train.
• Unit Anti Surge
• Unit Cooled Recycle
• Station Aftercoolers- a single set of coolers for the entire station
• Unit Anti Surge
• Station Cooled Recycle
38
Unit vs Station
Aftercoolers
![Page 39: Kane Ramsey and David Young v3 pdf - Enscope Limited - The layout of compressor stations and optimum offsite modularisation vs onsite build to increase construction efficiency](https://reader033.fdocuments.us/reader033/viewer/2022060112/556dcbbbd8b42a78768b4984/html5/thumbnails/39.jpg)
DEVELOPMENT | ENGINEERING | MANAGEMENT | COMPLETIONS
39
Unit vs Station
Aftercoolers
![Page 40: Kane Ramsey and David Young v3 pdf - Enscope Limited - The layout of compressor stations and optimum offsite modularisation vs onsite build to increase construction efficiency](https://reader033.fdocuments.us/reader033/viewer/2022060112/556dcbbbd8b42a78768b4984/html5/thumbnails/40.jpg)
DEVELOPMENT | ENGINEERING | MANAGEMENT | COMPLETIONS
UNIT AFTERCOOLERS
What are the benefits?
• Simple to operate and maintain
• Each set of coolers are designed for the individual compressor making selection easier.
• No start up or cool down issues
What are the downsides?
• Lower utilisation of installed capacity resulting in reduced station capacity for the given capital cost (where the equivalent amount of coolers are installed).
• Lower availability- If a cooler fan from one train fails and the compressor from the other train fails the station may not be operable at full capacity.
40
Unit vs Station
Aftercoolers
![Page 41: Kane Ramsey and David Young v3 pdf - Enscope Limited - The layout of compressor stations and optimum offsite modularisation vs onsite build to increase construction efficiency](https://reader033.fdocuments.us/reader033/viewer/2022060112/556dcbbbd8b42a78768b4984/html5/thumbnails/41.jpg)
DEVELOPMENT | ENGINEERING | MANAGEMENT | COMPLETIONS
41
STATION AFTERCOOLERS
Unit vs Station
Aftercoolers
![Page 42: Kane Ramsey and David Young v3 pdf - Enscope Limited - The layout of compressor stations and optimum offsite modularisation vs onsite build to increase construction efficiency](https://reader033.fdocuments.us/reader033/viewer/2022060112/556dcbbbd8b42a78768b4984/html5/thumbnails/42.jpg)
DEVELOPMENT | ENGINEERING | MANAGEMENT | COMPLETIONS
STATION AFTERCOOLERS
What are the benefits?
• Lower capital cost (if only one cooler per compressor is provided) or,
• If cooler bays for both units are installed you get better utilisation of the asset and more station cooling with one unit operating.
• Availability is greater (i.e. Compressors do not rely on an individual aftercooler)
What are the downsides?
• Issues with cool down and start up due to temperature build up in anti surge line (particularly with parallel configuration).
• Maintenance is more complex as process isolation of the cooler units will take out the entire station (unless additional valving is provided). 42
Unit vs Station
Aftercoolers
![Page 43: Kane Ramsey and David Young v3 pdf - Enscope Limited - The layout of compressor stations and optimum offsite modularisation vs onsite build to increase construction efficiency](https://reader033.fdocuments.us/reader033/viewer/2022060112/556dcbbbd8b42a78768b4984/html5/thumbnails/43.jpg)
DEVELOPMENT | ENGINEERING | MANAGEMENT | COMPLETIONS
ON-SKID CLOSE FIT ENCLOSURES
What are the benefits?
• Low cost option
• Medium level of acoustic attenuation
• Good for ventilation
What are the downsides?
• Poor access for maintenance
• Noise maybe a problem
43
Compressor
Enclosures
![Page 44: Kane Ramsey and David Young v3 pdf - Enscope Limited - The layout of compressor stations and optimum offsite modularisation vs onsite build to increase construction efficiency](https://reader033.fdocuments.us/reader033/viewer/2022060112/556dcbbbd8b42a78768b4984/html5/thumbnails/44.jpg)
DEVELOPMENT | ENGINEERING | MANAGEMENT | COMPLETIONS
OFF-SKID CLOSE FIT ENCLOSURES
What are the benefits?
• Good acoustic noise attenuation
• Medium for ventilation
• Moderate level of access for maintenance
What are the downsides?
• Middle range cost option
44
Compressor
Enclosures
![Page 45: Kane Ramsey and David Young v3 pdf - Enscope Limited - The layout of compressor stations and optimum offsite modularisation vs onsite build to increase construction efficiency](https://reader033.fdocuments.us/reader033/viewer/2022060112/556dcbbbd8b42a78768b4984/html5/thumbnails/45.jpg)
DEVELOPMENT | ENGINEERING | MANAGEMENT | COMPLETIONS
COMPRESSOR HALL
What are the benefits? • Good access for maintenance• Good acoustic attenuation
What are the downsides?• Highest cost option• Potentially higher insurance costs due to multiple
compressors operating in close proximity (escalation)• Maintenance issues if the other unit/s are running• Large amounts of ventilation maybe required
45
Compressor
Enclosures
![Page 46: Kane Ramsey and David Young v3 pdf - Enscope Limited - The layout of compressor stations and optimum offsite modularisation vs onsite build to increase construction efficiency](https://reader033.fdocuments.us/reader033/viewer/2022060112/556dcbbbd8b42a78768b4984/html5/thumbnails/46.jpg)
DEVELOPMENT | ENGINEERING | MANAGEMENT | COMPLETIONS
COMPRESSOR SHEDS
What are the benefits?
• Good ventilation (natural ventilation – i.e. mechanical ventilation system not required)
• Low cost option
• Good access for maintenance
What are the downsides?
• Low acoustic noise attenuation
46
Compressor
Enclosures
![Page 47: Kane Ramsey and David Young v3 pdf - Enscope Limited - The layout of compressor stations and optimum offsite modularisation vs onsite build to increase construction efficiency](https://reader033.fdocuments.us/reader033/viewer/2022060112/556dcbbbd8b42a78768b4984/html5/thumbnails/47.jpg)
DEVELOPMENT | ENGINEERING | MANAGEMENT | COMPLETIONS
47
Conclusion
• Key decisions such as contracting strategy, degree of modularisation, compressor and aftercooler configuration and the types of enclosures to be used are critical to the overall success of a compressor station project.
• We would recommend careful consideration and selection of these options be made very early in the project life cycle (iebefore commencement of the FEED) so as to increase the chances of overall project success.
• All of the various options discussed in this presentation have there respective advantages and disadvantages and we would not promote any particular option.
• In our experience the biggest factor in a projects success is ensuring it is suitably resources with experienced personnel from the outset, the key decisions are made early and these plans are executed in a timely manner.