Monitoring High Pressure Natural Gas Pipeline Ludek Novosad, - PowerPoint PPT Presentation

Long Term Axial Strain Monitoring High Pressure Natural Gas Pipeline Ludek Novosad, Geomonitoring s.r.o., Prague, Czech Republic

Where do we monitor pipelines • Landslide areas • Black coal undermined areas (settlement)

How do we measure axial strain • 3 spot weldable strain gages in a profile • Manual measurement with readout box • Automatic measurement with datalogger • Pipeline diameters are from 200 to 500mm

Position of the sensors • 3 strain gages in each profile - every 120 ° • distribution of the strain around circle profile forms a sine curve • calculation of maximum, minimum and their position on the circle

Sine curve theory • y 1 = a*sin(x 1 + b) + c • y 2 = a*sin(x 2 + b) + c • y 3 = a*sin(x 3 + b) + c • where • y 1, y 2, y 3 …reading at A,B,C [ MPa] • x 1, x 2, x 3 …A,B,C position [rad] • a … multiply constant - pipeline bending • b … deflection of bending plane • c … average strain without bending

Manual readings • We started in 1995 • Mostly undermined areas • Till now: - 173 profiles - 519 strain gages • They are measured 4 times a year (only the newest once a month)

Manual readings graph Axial Strain Changes in Time 180.00 360.0° 150.00 330.0° 120.00 300.0° A [Mpa] 90.00 270.0° B [Mpa] C [Mpa] axial strain change [MPa] 60.00 240.0° average A,B,C [Mpa] average A,B,C [°C] 30.00 210.0° strain change limit value (+) 0.00 180.0° strain change limit value (-) maximum [Mpa] -30.00 150.0° minimum [Mpa] -60.00 120.0° bending = (max - min)*.5 position of maximum [deg] -90.00 90.0° position of minimum [deg] -120.00 60.0° -150.00 30.0° -180.00 0.0° 1.7.2005 30.12.2005 1.7.2006 30.12.2006 1.7.2007 31.12.2007 30.6.2008 30.12.2008 1.7.2009 30.12.2009 1.7.2010 30.12.2010 1.7.2011 31.12.2011 30.6.2012 30.12.2012 1.7.2013 30.12.2013 1.7.2014 30.12.2014 1.7.2015 time

Manual readings graph Axial Strain Changes in Time 70.00 360.0° 60.00 330.0° 50.00 300.0° 40.00 270.0° Axial Strain Change [MPa] 30.00 240.0° Average A,B,C [Mpa] Average A,B,C [°C] 20.00 210.0° maximum [Mpa] minimum [Mpa] 10.00 180.0° bending = (max - min)*.5 0.00 150.0° position of maximum [deg] position of minimum [deg] -10.00 120.0° -20.00 90.0° -30.00 60.0° -40.00 30.0° -50.00 0.0° 1.1.1997 1.1.1998 1.1.1999 1.1.2000 1.1.2001 1.1.2002 1.1.2003 1.1.2004 1.1.2005 1.1.2006 1.1.2007 1.1.2008 1.1.2009 1.1.2010 1.1.2011 1.1.2012 1.1.2013 1.1.2014 1.1.2015 1.1.2016 Time

Relation between strain and temperature

Automatic readings

Pipeline construction

Automatic readings history • Started in year 2000 (249 strain gages, 11 CR10X, 22 MUXs, Siemens M20 modules) • 2008: New profiles (111 strain gages, 4 CR800, 9 MUXs, Siemens TC35i modules) • 2012: Dialed GSM connection changed to IP GPRS and Internet connection • 2013: AVW1 changed to AVW200 • 2013: Server rental (cloud) with Windows 2008 Server, LoggerNet Admin and VDV

Vista Data Vision (VDV)

VDV - Data visualization and their control • Feeding databases with historical data • Data update • Battery supply • Read data evaluation - rate of change - percentage of given limits - setting alarms (e-mails, SMS) - documentation data storage in the server

Battery supply and datalogger temperature since 2000

A profile graphs since 2008

Maximum and minimums

Percentage of maximum and minimum (3 profiles)

Rate of change

Relation between strain and temperature

A profile going to tension

Reading improvement after AVW200 installation (RoC)

Thank you...