helical pile applications in oil and gas industry* *an excerpt from the dfi fall 2010 technical...
TRANSCRIPT
Helical Pile Applications inOil and Gas Industry*
*an excerpt from the DFI Fall 2010 Technical Presentation
by Howard A. Perko, Ph.D., P.E.1 and Wayne Charlie, Ph.D., P.E.2
1Magnum Geo-Solutions, LLC2Colorado State UniversityCopyright 2011 – Howard A. Perko,
All Rights reserved. May be distributed and printed by express
written permission of the author only.
MAGNUM Informational Bulletin ISO-HAP1-11A
Copyright © 2011 – Howard A. Perko
• Why Use Helical Piles?• Historic Uses for Pipelines• Applications in Oil and Gas• Case History: Natural Gas Compressors• Case History: Oil Refinery Control
Building• Case History: Natural Gas Pipeline
Supports• Case History: Oil Refinery Pipe Rack
Retrofit• Contact Information
Outline
Copyright © 2011 – Howard A. Perko
Why Use Helical Piles?Save Money
Easy to Transport to Remote SitesDoesn’t Produce Drill SpoilEfficient Design
Save TimeRapid InstallationNo Concrete CuringSet Frames Directly on Piles
Proven Technology Invented in 1836Appears in 2009 IBC ISO2009 Accredited Manufacturer
Copyright © 2011 – Howard A. Perko
Historic Uses
1969 Hollander Patent:
Helical Piles for Pipeline Buoyancy Control
Used for over 40 years for pipeline support.
Now Public Domain
Copyright © 2011 – Howard A. Perko
Sample ApplicationsPipeline SupportsControl Buildings
Fuel TanksFilter Towers
Ancillary BuildingsCompressor Platforms
Dehydrator PadsStorage Tanks
SeparatorsCoalescersPipe Racks
Thrust BlocksScrubbers
Valve BoxesMaintenance Shops
…and much more.
Case History: Natural Gas Compressors
Copyright © 2011 – Howard A. Perko
Compressor Pad
90 tons
Designing the foundations for vibrating machines is not as simple as dividing the weight amongst the piles. The lifespan and maintenance cycle of compressors and other machines is greatly diminished with improper foundation design and excessive vibrations.
Copyright © 2011 – Howard A. Perko
Performance
For Equipment Operating at 1,000 to 1,400 cpm:
Target vibration amplitude = <0.0003 inches
Threshold for repairs = >0.0015 inches
Copyright © 2011 – Howard A. Perko
Vibration Amplification
The goal is to design an economical concrete-less helical pile supported foundation whose natural frequency (i.e. stiffness) is far enough away from resonance so as to avoid excessive vibration. A foundation can be designed hard or soft.
HARD SOFT
Re
so
na
nce
Copyright © 2011 – Howard A. Perko
Vibration Analysis
Vertical Spring Constant =
1/k = 1/kshaft + 1/khelix/soil
kshaft = Ag E / L
Khelix/soil = D/A (1-ν)/E 0.79
Lateral Spring Constant =k = dP / dδ
Driving Frequency = 1,000 - 1,400 Hz
Vertical = 1,200 HzRocking (short) = 1,200 HzRocking (long) = 1,200 HzLateral = 500 HzYawing = 500 Hz
Complex design requires special expertise. Gas company employed Dr. Howard Perko from Magnum Geo-Solutions, LLC as the lead consultant. Dr. Wayne Charlie, a professor of soil dynamics from Colorado State University, provided peer review.
Copyright © 2011 – Howard A. Perko
Engineering Support Team for
Magnum Piering, Inc.
Magnum Geo-Solutions, LLC
1-800-822-7437
• Licensed PE’s in 18 States
• Project Submittals• Design/Build Support• Expert Consultation
Magnum Geo-Solutions, LLC
Copyright © 2011 – Howard A. Perko
Compressor Foundation Plan
Resulting plan consisted of a steel mat with 12 vertical piles and 6 battered piles.
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Overall Site Layout
Compressor platforms were only part of overall foundation plan for gas compressor station. All components (pipe racks, filters, fuel skids, dehydrators, etc.) were constructed on helical piles.
Copyright © 2011 – Howard A. Perko
Pile Installation
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Example De-Hy Foundation
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Pipe Rack Foundations
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Compressor Pad Construction
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Completed Compressor Pad
Helical piles saved $100,000 per compressor pad versus conventional heavy reinforced concrete mat. Compressors were started without incident, vibrations were within target levels, and compressors continue to operate without flaw.
Case History: Oil Refinery Control
Building
Copyright © 2011 – Howard A. Perko
Control Building Plans
Recent regulation changes require blast-proof walls around refinery control buildings. This requires construction of new reinforced concrete enclosures. Use of helical piles does not produce drill spoil. Piles can resist compression and tension.
Copyright © 2011 – Howard A. Perko
Control Building Details
Jacobs Engineering used helical piles for compression, tension, and lateral loads (by battering) to support the new concrete enclosures.
Copyright © 2011 – Howard A. Perko
Helical Pile Details
Magnum Geo-Solutions provided engineering support. Magnum Piering, Inc. supplied products. Design compression and tension capacity = 110 kips working.
Copyright © 2011 – Howard A. Perko
Installation and Load Tests
Load tests passed with good results. Measured 0.28 inches movement at 110 kips design compression and tension loads. Installation was completed on budget and on schedule.
Case History: Natural Gas Pipeline
Supports
Copyright © 2011 – Howard A. Perko
Foundation Plan
Hunt, Guillot & Associates, LLC of Ruston, LA provided design of compressor station with helical piles and concrete pile caps.
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Pipeline Support Details
Copyright © 2011 – Howard A. Perko
Soil Boring
Subsurface conditions consisted of high plastic clay over very stiff lean clay (SPT N>50 bpf).
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Installation Photos
MH425 helical piles installed on schedule and on budget.
Case History: Refinery Pipeline Supports
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Support Detail
Several miles of existing pipe lines constructed on timber piles with steel cross members experienced settlement and degradation. This detail showing MH530 piles with threadbar and steel cross beam was submitted as a solution.
Copyright © 2011 – Howard A. Perko
Installation Photographs
Helical piles were installed on schedule despite challenging work environment. Contractor was able to successfully and safely lift and re-align pipe lines.
Contact InformationMagnum Piering, Inc.
www.magnumpiering.com800-822-PIER (7437)
6082 Schumacher Park DriveWest Chester, OH 45069