Grid Migration White Paper
Robert C. White, Jr.
Changing land grids is a recurring topic in the natural resource industry. A desire to change arises for a variety of reasons. Your company may have been using a public or an internal source, and now your holdings have expanded and there is a need to use better, maintained, and seamless data. You may use data from another vendor and now wish to take advantage of WhiteStar Lot and Tract data for more precise automapping, or you may be tired of paying far too much under another vendor’s licensing agreement and wish to save your company tens of thousands of dollars.
There is a general perception that once a polygon is “anchored” or “built upon” a particular land grid it is then difficult or somehow inappropriate to change it. This is perceived as a large problem / obstacle to switching vendors, but it is exactly the same problem as when a vendor issues an update or has changed the way they process their data and the underlying data are now somehow different. In this white paper, we will look at the considerations a company faces when switching from one source to another.
Whatever the case may be, a key obstacle to changing land grid data from one source or data vendor to another is that the base polygons (i.e. section, township, and range) differ slightly (and sometime greatly) from source to source. In your existing data there may be topological gaps and overlaps involving different jurisdictions such as counties and states and even international boundaries that can all fail to edge-match.
Your company probably has many file folders of lease or legal description documents for a variety of project areas. Part of these data include a lease legal description based on either Survey-Block-Abstract or Lot-Tract-Subdivision in Texas or Lot-Section-Township-Range in the Public Land Survey States.
Whether your company updates their data from state sources or switches vendors, the problem is essentially the same. The concern is that there will be a large amount of work involved to switch the polygons from one data source to another. This white paper will lay out a proven strategy for approaching this problem and demonstrate why the fear is largely unfounded.
One might ask, “What are the benefits of maintaining an up-to-date land grid where these issues are resolved?” There are several answers. We have informally vetted our “self healing grid process” with several members of the APSG (http://www.apsg.info). They feel it is the only way to eventually arrive at the ultimate land grid - i.e. GPS-quality corners for everything. Self healing is a process of obtaining and incorporating high quality data as it becomes available and then setting the attribute and geometry modification dates so that consumers of the data can run a query to see if changed polygons intersect their area of interest.
Secondly, would you risk a multi million project on anything other than the best data? The land grid component is a relatively small expenditure considering the cost of the decisions that arise from using the product.
Thirdly, an up-to-date and maintained land grid is the foundation of all mapping in an organization. GPS or survey grade corners can be added to the product providing a repository for not only better quality corners but also metadata on land survey monuments such as coordinates, quality, and source. Moreover, there are likely several other users and potential users of land grid data inside of your company. These include exploration, land, pipeline, surveyors, field personnel, transporters, fleet management, and upper management. Each group expects and deserves the most highly accurate foundational data for its projects and presentations. In addition, expensive infrastructure should be planned and charted on the best quality land survey data available. Can your land grid serve as a platform for integrating other survey related data?
Fourthly, one should consider the overall cost of licensing compared to what you are investing now. Does switching to an actively maintained land grid plus the costs of migrating the polygons make sense? As a rule of thumb, polygon adjustment to a new land grid costs about $1 per polygon. Users can quickly see the cost benefit of a one time expenditure. In some cases, the money saved can amount to tens - even hundreds - of thousands of dollars per year, particularly for those companies that are licensed according to the questionable “BOE” model where pricing depends upon the amount of hydrocarbons produced rather than a flat fee.
A proper land survey is not just a product but also a partnership between the company and its community of users. Our community of users is encouraged to share its GPS quality land survey data with WhiteStar so that the corners and monuments can be properly integrated into the product. The community benefits from the ever-increasing quality of the WhiteStar Grid. Recently we commissioned a market survey among our users to determine among other things the experienced accuracy of our data. The data reveals that fully 90% of the oil and gas community believe the data to be the most accurate data available on the market. It is clear that our strategy of continuous improvement of the data is working. In addition, it embraces your highly valuable survey data and gives it a place to be maintained, integrated, and used. Before, these data sets likely lived in isolated silos inside your company.
A rapidly growing oil and gas company uses another vendor’s land grid to map their oil and gas leases. Among other issues, the company was plagued with data problems, for example, gaps and overlaps in the data and edge matching problems among states. Over a period of time, the company decides it does not want to be in the data custodian business and wants a single, seamless land grid upon which to map their data assets.
This company endeavored to switch to WhiteStar Grid and remap their polygons to fit our grid. They identified a “move day” after which projects were only to be created on the new grid. They hired us to spatially adjust the approximately 10,000 polygons they could not re-map automatically. The work was performed inside of a month and the company is now realizing a savings of many tens of thousands of dollars per year.
Switching data sources can be viewed as exactly the same task as a large update. Many users are in this situation where they have not updated their land grid in many years. There is fear of the chaos that might result. We have polled our prospects and users and discovered that many companies simply ignore the issue entirely and do not engage in updates. Is that a best practice or proper strategy? What are the risks of following that policy?
For the first decade of the GIS revolution, software vendors put a lot of emphasis on purchasing software and almost no emphasis or budget on acquiring data. Secondly, almost no emphasis was placed on maintenance of that data - primarily because data maintenance is a permanent, ongoing, expensive endeavor. One reason WhiteStar moved to a subscription model was to spread out the costs of maintenance among many users. In the past 3-5 years, customers have come to realize that the real investment must be made in improving data and that obtaining low quality data from state data repackaged web sites is costly.
GPS coordinates for corners are becoming increasingly available allowing the base map data to continuously improve. GPS coordinates are obtained from a variety of sources and vetted, then dropped into a point attribute feature class. The lines connecting the corners (or other ancillary points) are then redrawn. The point feature class contains several metadata items including the source of the GPS coordinate, the quality of the GPS coordinate, and the date it was added.
In addition, WhiteStar has added the AMODDATE and GMODDATE attributes to all of its data. These attributes give the date, for each polygon, that the Attributes (text features) of a polygon were last changed and the date the geometry was last changed for that polygon. The oil company was then able to run a query on the data to determine which polygons had changed since the last update from the data vendor or data source. We can suggest several strategies for re-mapping polygons onto a new land grid.
Approaches for re-mapping polygons
In an ideal world, all corners of the land survey would be recorded using professional GPS level accuracy and precision and all other parcels tied to these corners. In practice, this will take a long time to achieve as there are many millions of corners in the Public and Texas Land Survey systems. Obviously if you have GPS coordinates, your lease polygons should be rectified to the “known” corners and then it will never need to be edited again.
Aliquot Described Leases / Parcels.
Very commonly, polygons must be mapped to a new land grid and the source for the polygon is a legal description. Software offering from companies like Quorum Business Solutions (http://www.qbsol.com) can take text format legal descriptions such as 6 53N 69W 15 N/2 and create a polygon that precisely fits the land grid.
Metes and Bounds Parcels / Tax Parcels / Texas Leases
Other polygons including metes-and-bounds described polygons must be adjusted using a variety of spatial adjustment tools and proprietary techniques. Often the new land base is only slightly different than the old base - but enough to require adjustment. Our experience says that this costs about $1 per polygon to perform.
In summary, there are a lot of myths and fear around switching land grid sources that do not pan out in reality. Switching from a high cost BOE based licensing scheme to a fixed licensing scheme is an opportunity to save tens of thousands of dollars per year with a one time investment of approximately $1 per polygon to spatially adjust leases that need to be handled “manually”. In combination with auto-mapping software, this cost can also be minimized. We believe that failure to update your land grid is not a solution and imperils multi million dollar projects.