Apache CanadaCoordinates Workshop

• CBM inter-well distance calculation methods used by Apache and ERCB

• Map projections

Apache calculation

• Latitude and longitude of first point is A1 & B1

• Latitude and longitude of second point is A2 & B2

• The arc distance can be computed as: Arccos [cos(A1)cos(B1)cos(A2)cos(B2) + cos(A1)sin(B1)cos(A2)sin(B2) +

sin(A1)sin(A2)]/360 * 2Pi * r

• In navigation, this is a great circle distance between two points on the surface of a sphere

ERCB calculation• Gov’t uses ATS ver 4.1 (MATS 2005) for lat/lon of

the nearest section corner

• ‘Metes and bounds’ from section corner used to validate lat/lon of the surface location

• Directional/horizontal survey used to compute lat/long of the bottom hole

• Latitude and longitude of the bottom hole are projected onto a 10TM map projection in their GIS

• A 3 km buffer circle is created around the control well

• Wells to be licensed more than 3 km from the control well are non-compliant

• ERCB is using a 10TM map grid distance between the wells

An example of the differencesApache 8-31-33-27-W4M to Hz 6-5-34-27-W4M

Great Circle Distance NAD 83 UTM Coordinate Inverse

Latitude Longitude Lat (rad) Long (rad) Northing Easting

A1 51.888161 B1 -113.800451 0.905619 -1.986193 A1 5752306.2 B1 307287.0A2 51.871112 B2 -113.811354 0.905322 -1.986383 A2 5750439.4 B2 306463.7

Distance (m) Distance (m)

2040.383 2040.286

Apache 4-4-30-27-W4M to 16-11-30-27-W4M

Great Circle Distance NAD 27 UTM Coordinate Inverse

Latitude Longitude Lat (rad) Long (rad) Northing Easting

51.536004 -113.750871 0.899473 -1.985327 5712793.0 309282.951.558969 -113.688485 0.899874 -1.984238 5715185.9 313702.8

Distance (m) Distance (m)

5018.536 5026.081

The 10TM distance• Text Text

Map Projections

Transverse Mercator Projectionsin Alberta

Metadata – where would you be without it?• Lat: 51.536004°

• Lon: -113.750871°

Metadata – where would you be without it?• North: 5712793.0

• East: 309282.9

• UTM Zone 12

Recommendations• Inverse between NAD83

UTM coordinates as shown on well site plan for well license application

• Use online tools as a check

Online Resources• Natural Resources Canada – Geodetic Tools

• http://www.geod.nrcan.gc.ca/tools-outils/index_e.php• http://www.geod.nrcan.gc.ca/apps/indir/inverse_e.php

• Movable Type Scripts – Great Circle Distance• http://www.movable-type.co.uk/scripts/latlong.html

• United States Geodetic Survey – “Map Projections: A Working Manual”• http://pubs.er.usgs.gov/usgspubs/pp/pp1395

• The Geographer’s Craft – Map Projections• http://www.colorado.edu/geography/gcraft/notes/mapproj/mapproj_f.html

• Moving to NAD83: Impacts and Issues for Oil and Gas Companies…• http://www.cseg.ca/conventions/abstracts/2002/2002abstracts/

Callaghan_S_Boudreault_D_Moving_To_NAD83_BUS-1.pdf

• CAPP: Migrating from NAD27 to NAD83…• http://www.divestco.com/getdoc/0556a64e-f05f-4a61-a0c4-

e6046d67b4a6/CAPP_Migrating-from-NAD27-to-NAD83.aspx

Questions?