Well Symbology Standards
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I am sure many, if not most, in Geospatial or Data Management have done a review of well symbology. The first few times one undertakes the exercise of reviewing and mapping well attributes to well symbols is actually quite interesting! Then at some point either apathy or frustration will set in. Although I am getting close to apathy, I decided to take one more look, and I committed to writing up a comparison on the well symbols sets that were referenced in the Well Symbology Standards LinkedIn discussion thread. This review is not intended to recommend or validate specific symbols, or to be comprehensive. The intent is to highlight the similarities and differences in just these three symbol sets. The symbol sets referenced in the discussion were:
The first thing a person notices about well symbol sets is the huge number of symbols included in a given set. This comes from the fact the symbols are really a combination of symbol overlays, which by their very nature, quickly multiply into a large number. So, the first step in establishing an approach to review such long list of symbols in a meaningful way is by breaking the sets into some basic groups that are usually combined in the overlaying of symbols. I am sure this approach is biased from the PPDM document showing the PPDM well symbols displayed as a matrix showing the production type (oil, gas, condensate..) along one axis and the production status (abandoned, shut-in…) along the other axis. This matrix ensures a sense of consistency in the symbol set by assuring the symbol on one axis is overlaid with the other axis. Overlay the symbol of “oil” with the symbol of “Abandoned” and you get an “Abandoned oil” well.
So, for this comparison, the symbols have been broken into hydrocarbon production, hydrocarbon shows, production status, injectors/disposal, and finally a group of miscellaneous symbols. The miscellaneous symbols are those used to account for well characteristics not generally consistent across the three symbol sets. This ensures we are just comparing small sets of distinct symbols, rather than the multitude of symbols that can be achieved by overlaying these together.
The first group of symbols are used for the wells producing a hydrocarbon:
As you can see we have agreement on the Oil and Gas well symbols! That would be a good place to stop, as we will not see such agreement between the three sets again. It should also be noted that even within these small groups these symbols can be combined. For example:
Oil and Gas well is the combination of the oil symbol and gas symbol in all the sets.
Note that because Condensate in the PPDM set already includes the Gas symbol, the symbol for Condensate and Gas cannot just be an overlay of the Gas and Condensate symbols; instead it is a new symbol. The occurrence of this is rare, as each set has taken care that symbols can usually be combined.
Condensate and Gas (PPDM)
The next group is hydrocarbon shows:
The Shell symbol set distinguishes the shows based on an interpretation of whether the well could be productive. The ones on the right are “interpreted productive.” Now these symbols can be combined with the production symbols above to produce new symbols. So we can have an oil well with gas shows, or a gas well with oil shows.
The next group is the production status symbol. Note that in all the examples shown below the status has been overlaid on an oil well symbol.
Now the complexity of this group comes from the many terms that are commonly used to describe this status. Common terms are abandoned, temporarily abandoned, junked, junked and abandoned, plugged and abandoned, suspended, suspending, shut in, closed in, plugged, multiple completions, exhausted…. You get the point. Sometimes a symbol is created to distinguish between these terms, and none of the sets include all the terms listed above. In an attempt to compress the above table and actually compare symbols, some liberty was taken to combine similar terms. For example, Shell uses the term “closed in,” and does not reference “shut-in;” PPDM uses “shut-in” and doesn’t reference “closed in.”
The next group is the injectors and Disposals. I broke this group out because in this group PPDM and Shell have taken a different approach, and FGDC does not explicitly call out the injector classification.
For the Shell symbols set a letter is used to classify the type of gas or fluid injected, so an N by the injector symbol is used for Nitrogen Injection; a W for water; an S for steam; and so on. So with this basic symbol it can be annotated for any type of injection. The PPDM symbol set uses an “Injector” symbol that must be used in combination with the symbol used for water, steam, CO2….
PPDM does not call out any symbol for disposal.
Finally, some miscellaneous symbols that each set has that have little consistency between them.
For PPDM these types of wells have a specific symbol:
An example of some FCGD unique symbols:
and, finally some unique examples from shell:
Although most of this writing is stating the obvious, being able to see the differences side-by-side helps understand the scope of what an industry standard means. There is a lot of history in just these three sets, and change is hard. The discussion on Standard Well symbols is not over, and most likely will be held again (and again, and again).
So at this point, I would like to thank those who had sent me their well symbols sets. Although I do not include the symbols as part of the review, it was interesting to see the variety of symbols used and some of the approaches used to achieve a standard set for either a local, regional team or company symbol set. What is surprising, or maybe not, is there is very little agreement in those symbols sets with any of the above symbols sets, other than Oil and Gas – which is all that matters! Right?
Scott Sitzman, PUG Chairman
The PUG would like to thank our sponsors for their support: Blueback Reservoir, BP, Coler & Colantonio (a CHA company), Esri, Exprodat, Latitude, Logic Solutions Group, GeoPropel, Landworks, Schlumberger, TeachMeGIS and Trimble.
Links used in the Article:
LinkedIn Discussion Thread: https://www.linkedin.com/groupItem?view=&gid=1832102&type=member&item=5885532683773165572
FGCD Symbol Set: http://ngmdb.usgs.gov/fgdc_gds/geolsymstd/fgdc-geolsym-sec19.pdf
PPDM Symbol Set: http://www.ppdm.org/standards/wellstatus