Several weeks ago I wrote about US Well Numbers and the basics of how they are numbered and who numbers them along with the standards committee that sets the rules.
Today I’m writing about the Canadian system which is very different from the US but as a geologist I find it elegant, logical and very easy to understand.
In order to understand the Canadian oil and gas well numbering scheme you need to understand the Canadian land system. The elegant part of the numbering scheme is that the well number is the location of the well based on the land grid, so as soon as you see the number you instantly know where it is located.
I’m going to be focusing on Western Canada (Manitoba and west) because that covers the bulk of the wells in Canada.
There are 4 land grid systems in Canada. The DLS (Dominion Land Survey) covers Manitoba, Saskatchewan, Alberta and a small amount of British Columbia. The NTS (National Topographic Survey) covers British Columbia, except the small part that was surveyed using the DLS system.
Source: https://dl.ppdm.org/dl/551
DLS
The Dominion Land Survey covers most of Western Canada. It is a township and range system type layout based on seven meridians that run north/south across Canada. The first or prime meridian is located at 97° 27’ 28.4”W, the second at 102°W, third at 106°W, fourth at 110°W fifth at 114°W sixth at 118°W and seventh at 122°W (there is also an 8th meridian called the coast meridian). Description of the location of a township is usually written in the format 3-3-W2 – which is read “township 3, range 3, west of meridian 2”.
Townships are organized with 36 sections (6 by 6 one mile sections) but unlike the US they are numbered starting in the lower right of the township and move horizontally and snake upward with section 36 in the upper right of the township.
Each section is divided into 16 legal subdivisions and they are numbered from 1 to 16 with number on in the lower right corner and the numbers move horizontally and snake upward ending in legal subdivision 16 in the upper right corner.
In the DLS system the edge of one section doesn’t always touch the edge of section next to it. They have something called a road allowance which is exactly as the name suggests, a small strip of land set aside for a road. Depending on when the original survey took place the width can vary. Also the placement of the road allowance can vary – in some areas they are between every section going north/south and east/west. In other areas they are every mile going north/south and every 2 miles going east/west.
A typical Canadian well number might look like this: 100/12-04-091-05-W5/00
100/12-04-091-05-W5/00
The 1 indicates the well is located in the DLS survey system. 2 indicates it is in the NTS and BC grid system, 3 in the Federal Permit system and 4 in the Geodetic system.
100/12-04-091-05-W5/00
The 00 indicates it is the first and only well in the legal subdivision.
100/12-04-091-05-W5/00
The legal subdivision number. Numbers from 1 to 16
100/12-04-091-05-W5/00
Section number. Valid range between 1 and 36
100/12-04-091-05-W5/00
This is the Township number. Townships start at the southern Canadian border and always go north.
100/12-04-091-05-W5/00
This is the range number or the number of townships east or west of the meridian.
100/12-04-091-05-W5/00
This is the number of townships west of the 5th meridian.
100/12-04-091-05-W5/00
Always 0. It is padding so the number of characters always stays at 16 no matter what the survey system the well is located in.
100/12-04-091-05-W5/00
This is the event sequence number, which can be separate and unique set of geological or production data or a new borehole. Subsequent events are labeled 1-9-A…. Alberta does not use the number 1 but instead uses 2 for the second event. Saskatchewan uses special identification code instead of an event sequence code.
NTS
The National Topographic Series is a system that identifies a location based upon a series of maps published by the government. In British Columbia the general map sheets covered are 82, 92-94, 103-104, each of those map sheets are divided into Lettered Quandrangle maps that are lettered from A in the lower right corner to P in the upper right corner moving horizontally and snaking upward. each Lettered Mapsheet is divided into 16 parts (4 by 4 called a grid) numbered 1 in the lower right corner and 16 in the upper right corner, numbering horizontally and snaking upward to the upper right corner.
Each grid is divided into 12 blocks (4 columns by 3 rows) lettered A-L. Each block is divided into 100 units (10 by 10) numbered 1-100. The units are numbered consecutively across each row with one in the lower right corner and 11 back again to the right above the number 1. This ends with 100 in the upper left corner. Each unit is divided into 4 quarter units (2 by 2) which are lettered a-d in a clockwise fashion starting in the lower right corner.
So the well 200/a-20-B/094-H-09/00 would be located as follows
200/a-20-B/094-H-09/00
Indicates the NTS system to located the well
200/a-20-B/094-H-09/00
Located within map 94
200/a-20-B/094-H-09/00
On mapsheet H
200/a-20-B/094-H-09/00
Grid 9
200/a-20-B/094-H-09/00
Block B
200/a-20-B/094-H-09/00
Unit 20
200/a-20-B/094-H-09/00
Quarter unit a
200/a-20-B/094-H-09/00
This is the only well in the ¼ unit.
200/a-20-B/094-H-09/00
Always 0. It is padding so the number of characters always stays at 16 no matter what the survey system the well is located in.
200/a-20-B/094-H-09/00
This is the event sequence number – similar to the way it is used in the DLS system
As you can see the Canadian oil and gas well numbering scheme is logical and well thought out and the best thing is, it is almost impossible to mis-locate a well.
