Norwegian Continental Shelf and
ED50
Use of ED50
2013-04-30
Subjects
• Why this presentaton
• Many ways to display your position
• What is a datum
• Navigational charts
• Jens Evensen and continental borders
• Why do we use ED50 on Norwegian Continental Shelf
• Seismic interpretation and well trajectory (D&W)
• Projection of ED50
• Datum transformation (dimensions and errors)
• Examples
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Why this presentation?
• What is ED50?
• Why is ED50 used, why not GPS?
• Is latitude and longitude ED50?
• What is this UTM?
• Is it a big difference between thoose two?
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Many ways to display your position
Geocentric coordinates
Geographic coordinates
UTM coordinates
•
X, Y, Z
•
Latitude Φ, Longitude λ
•
North/South, East/West
•
Origo in earth center
•
Origo in earth center
•
•
No ellipsoid used
•
No ellipsoide used
Origo at equator and given
central meridian
•
Need ellipsiod
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Many ways to display your position
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What is a datum
Norwegian datum
• NGO1948
Origo
• ED50
• WGS84
• EUREF89
Perpendicular axes
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Navigational charts
• Up to 1957
− NGO1948
• 1957 – 1992
− ED50
• From 1992
− WGS84
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Jens Evensen and continental borders
• Norway <-> UK
• March 10th 1965
− Navigational chart no. 301
− 1 : 1 000 000
− 8 points defining border
• Norway <-> Denmark
• December 8th 1965
− Navigational chart no. 301
− 1 : 1 000 000
Carl Erik Fleicher, Erik Løddesøl
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Why do we use ED50 on Norwegian Continental Shelf
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Why do we use ED50 on Norwegian Continental Shelf
Aktivitetsforskriften
Veiledning
• § 82
• § 82
− Brønnens lokasjon og bane skal
være kjent til enhver tid og velges
på grunnlag av brønnparametere
som har betydning for en sikker
bore- og brønnaktivitet.
• For å oppfylle kravet til brønnens
lokasjon og bane som nevnt i første
ledd, bør standarden NORSOK D-010
kapittel 4.3 og 5.7.4 brukes, med
følgende tillegg:
• brønnens lokasjon og bane bør angis i
Universal Transverse of Mercator
(UTM)-koordinater.
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Why do we use ED50 on Norwegian Continental Shelf
• 5.7.4.2 Well trajectory measurements
• The following apply:
• a) The surface location coordinates of the well bore center shall be determined with use of differential
global positioning system. Well slot co-ordinates can be established by measurements from a known
reference point (fixed point on a platform, sub sea template, etc.).
• b) During drilling of new formation, measurement of well bore inclination and direction shall be obtained at
least every 100 m MD. All survey plots should be referenced to grid north.
• c) The position of the well bore being drilled (reference well) and the distance to adjacent wells (object well)
shall be known at all times. The minimum curvature method or other equivalent models should be used.
• d) A model for quantifying the uncertainty shall be established. The probability for the well bore to be within
the calculated uncertainty ellipses should exceed 95 %.
• e) Minimum acceptable separation distance between well bores and risk reducing actions shall be defined.
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Why do we use ED50 on Norwegian Continental Shelf
• Norwegian Petroleum Directorate (OD)
− Registration of wells
• Datum to be used is ED50, geographical coordinates
− (no accuracies required)
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Seismic interpretation and well trajectory (D&W)
Large fields
High accuracy
• 1021km2
• Shallow gas pockets
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Projection of ED50
ED50 (International 1924)
WGS84
• Semi-major axis a = 6 378 388m
• Semi-major axis a = 6 378 137m
• Semi-minor axis b = 6 356 911.946m
• Semi-minor axis b = 6 356 752.314m
• Flattening = 1/297.0
• Flattening = 1/298.257223563
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Projection of ED50
Transformation
• Translation
• Rotation
• Scale factor
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Parameters
Datum Transformation
• We start with following position
61°04'54.5"N
• Dose this position tell you where you are?
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2°29'49.9"E
Datum Transformation
• NO
• If we add following information
DATUM ED50
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Datum Transformation
• YES
• What with theese coordinates?
Northing 6477873.916 m
Easting 437502.434 m
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Datum Transformation
• NO
• If we add following information
Northing 6477873.916 m
Easting 437502.434 m
DATUM ED50
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Datum Transformation
• NO
• If we add following information
Northing 6477873.916 m
Easting 437502.434 m
DATUM ED50 UTM Zone 31N
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Datum Transformation
• YES
Northing 6477873.916 m
Easting 437502.434 m
DATUM ED50 UTM Zone 31N
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Datum Transformation
Best practise to display a position
Geographical
Coordinates
UTM Coordinates
Northing 6477873.916 m
Easting 437502.434 m
DATUM ED50
DATUM ED50 UTM Zone 31N
CM003E
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Datum Transformation
− GPS receivers will normally output WGS84 datum
− GPS raw data are processed by a navigation SW. This SW will be set up to
convert WGS 84 into the requiered datum.
− For Datum transformation Statoil use mainly two different programs to convert
between different datums
• Geomatrix Inca
• Blue Marble Desktop
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Examples
Lets look at som error figures between WGS84 and ED50
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Examples
ED50 UTM Zone 34N CM21E ESPG 1612 (N62)
Lat
:71°35'30.975"
Long
:21°16'33.860"
Northing :7943655.0 m
Easting :509730.7 m
WGS84 UTM Zone 34N CM21E ESPG 1612 (N62)
Lat
:71°35'31.507"
Long
:21°16'28.367"
Northing :7943456.0 m
Easting :509676.3m
Distance between theese two positions
56.3m
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Examples
ED 50 UTM Zone 31N CM03E ESPG 1613 (S62)
Lat
: 58° 26' 08.80"N
Long
: 01° 55' 46.80"E
Northing : 6 477 873.9 m
Easting : 437 502.4 m
WGS84 UTM Zone 31N CM03E ESPG 1613 (S62)
Lat
: 58°26'06.59"N
Long
: 1°55'41.11"E
Northing : 6477658.8 m
Easting : 437412.2 m
Distance between theese two positions
114,8m
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Examles
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Expamles
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Expamles
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Expamles
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Examples
Difference between WGS84 and ED 50 in the Norwegian
continental shelf are between 50 and 300 meters.
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Norwegian Continental Shelf and ED50
Bength Eriksen
Senior Surveyor
E-mail: beneri@statoil.com
Tel: +47 936 92 070
www.statoil.com
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