I have not put anything on this blog in awhile, been too busy. But I recently I was looking at a number of competitor’s websites. It’s amazing to me how many companies follow trends like a pack of lemmings even though surface geochemical (SG) methods clearly do not work in certain types of plays in our industry. The trend five years ago, for some SG companies, was the ability to claim that they could define coal-bed methane reservoirs. From experience, I have reviewed a Calgary based company’s work in Northern Ontario where there were vast swamps. The Calgary company claimed to have had defined a variety of good targets to extract gas from coals or in actuality lignites. (Lignites do not generate any real gas) As I was brought on to run Admiral Bay, we were in the process of testing a number of anomalies that were committed to by the previous management. None of the supposed coal bed methane targets panned out. It seemed that there were other sources of gas than from the coals in a vast swamp or in Calgary.
Then there is the Powder River. Another company in Denver claimed to be defining the gas productivity of the Cretaceous\Tertiary coals of the Powder River for JM Huber. A few years ago I was interviewed to run JM Huber’s entire oil and gas operations. Management had abruptly changed and they were ultimately seeking to restart the petroleum division. I had a chance to talk to the remaining geologists and some of the management about SG for coal bed methane. They said it never would have worked and I confirmed that it did not by looking at the subsequent production history where the surveys were and/or the lack there of with the associated gas wells. It hard to discern methane from different sources with SG. Actually its not likely without isotope work and even then there will be questions.
Now that shale plays are the target “du jour” in the industry, certain SG companies are at it again, claiming “all sorts of things”. Well, once again it may be easy to define faults with leakage at the surface. But, many of these faults and fracture systems have nothing to do with any reservoir at depth; whether in unconventional or conventional pays. As someone who has completed a number of highly detailed surveys in the northern Denver Basin where the Niobrara and the Bakken Play in the Williston Basin are being exploited, it is rare when linear trends are seen that may define fault or a fracture system. Typically SG anomalies that define a fault or fracture system at the surface are not trapping at depth in this author’s opinion.
Case in point, recently, in Texas, the Texas Railroad Commission and the EPA have been fighting over the source of gas in ground water wells in the Ft. Worth area. The Texas Railroad Commission has clearly identified the gas at the surface and in the ground water as being leakage from shallower rocks. The EPA is trying to say it is from the deeper Barnet. It is with this reasoning they would be able to get a major producer to pay for the clean up.
This creates an issue for doing SG in any shale play. Most shale plays are in very oil and gas prolific basins. There is a reason these shales are generating. There is a reason why there are numerous conventional reservoirs in these shale play areas. There are also reasons why shales do not give a tremendous amount of leakage at the surface. Essentially, since the shales are both source and seal. In many plays, producers avoid faults or fracture swarms as they see an increase water production and much lower if not zero hydrocarbon volumes. Thus, these faults and fractures are highways to shallower reservoirs above or directly to the surface.
Consequently, buyer beware. SG has its uses; but in shale and coal bed methane reservoirs it does not.