Welcome to 2015! We’d like to start out this year with a series of close-up looks at the challenges of grid mapping in our Lots and Tracts states, starting today with a focus on Oklahoma.
Each state we’ve researched and mapped has had unique challenges, and Oklahoma was no exception. Our essential WhiteStar Grid dataset contains all of the one-mile-square section data for the country, but accurate sub-section surveys are needed to really map your leases accurately – a primary driver behind our original decision to build these very detailed datasets.
Lots are the parts of a section that generally fall in excess or short of 40 acres. The original set of plats for that township show you graphically the location of the lots, and this is the primary data source for WhiteStar Lots and Tracts.
Lots and Tracts is the layer you want for the most accurate mapping possible. Sections are often subdivided into numbered lots – for example, T3S, R4W, Sec 5, Lots 8,11,15 – a common way of describing oil and gas leases. These often quite irregular polygons of land have come about in different ways.
One of the original goals of the Public Land Survey System was to preserve as many exactly-40-acre quarter-quarter pieces as possible. The overage or shortfall is then assigned to lots. In a “regular” township, these lots typically show up in the northernmost and westernmost tiers of sections within a township.
Survey errors, navigable water, state boundaries, and old Indian boundaries can (and frequently do) break this rule. Many rivers in Oklahoma are highly lotted, particularly along the major rivers such as the Canadian, Red, and Arkansas.
Lots 1, 2, 3, and 4 ought to correspond to the NENE, NWNE, NENW, and NWNW of the section. This is sometimes true - but often it is not. It’s remarkably easy to produce an embarrassingly incorrect map with assumptions. You really need to inspect the quarter-quarter layer contained in our data, supplemented with lot data, to see the entire picture.
Here’s the thing – if you map a lease to the nearest section, it could be wildly inaccurate. If you map a lease using software that interpolates sub-section descriptions by automatically dividing the parent section, it may be closer to the truth, but still without definitive geometry.
And if your lease polygon is inaccurate, your acreages, lease royalties, well spacing and more may all be inaccurate too.
Oil and gas company operations demand accurate maps. We’ve taken on the enormous task of creating this data, ready for you to use – and no other company or government agency has done that. It’s a truly unique dataset, and it can increase your lease mapping accuracy by leaps and bounds.
Even if you are using another underlying grid source, we can provide georeferenced scanned plats for the townships in Oklahoma, and you can supplement your land grid, regardless of the source!
The WhiteStar 2015 Spring Tour - Save the Date!
After a very successful tour through Texas in the fall, we’ll be back on the road soon for a trip through more northerly latitudes. Save the date for the free breakfast meeting and presentation most convenient for you!
March 26th - Denver
March 31st - Oklahoma City
April 1st – Tulsa
Apr 2nd – Wichita
Watch your inbox for event announcements and registration coming soon! If you’d like to ensure you receive an invitation, email Adam Cordova.
Esri Petroleum GIS Conference
As always, we will be at the Esri Petroleum GIS Conference, this year from April 8th to 10th, at the George R. Brown Convention Center in Houston. Stop by and see us at booth #505!