Friday, January 13, 2012

The Name Game

I received numerous calls and emails this week after two articles were published about the TMS in industry magazines.  The questions regard the naming of the "shale of interest" across central Louisiana.  Some parties use the name "Louisiana Eagle Ford" versus the "Tuscaloosa Marine Shale" (aka TMS).  The desire to associate with the Eagle Ford Shale of south Texas is obvious from a marketers stand point.  As they say, "perception is reality".  No one can be faulted for that.

I personally don't care for the name "Tuscaloosa Marine Shale", but the naming convention was created before I was born.  There are many marine shales in the Tuscaloosa interval, so that name is not very unique or descriptive.  Lithostratigraphic nomenclature usually loses its value once you "leave the neighborhood".  Technically, based on over twenty years of sequence stratigraphic work across the trend, I identify this interval as the "upper portion of the Tuscaloosa A Transgressive Systems Tract".  The acronym UPTATST might be hard to sell. 

Type Log:
http://www.ameliaresources.com/documents/tuscaloosatrend/Amelia%20Resources%20LLC%20WEBSITE%20TUSCALOOSA%20MARINE%20SHALE%20Type%20Log%20June%202011.pdf

The shale being pursued across Vernon, Rapides, and Sabine Parishes is the UPTATST as it is to the east in the Florida Parishes and Mississippi.  They are age equivalent, but are part of different hydrocarbon systems and don't share the same rock properties.  In a broad sense, I don't believe that they share the same hydrocarbon saturations.  The drilling results will deliver the "proof in the pudding" over the coming years.  High initial production rates with stable declines will be the ticket to profitability.

At the end of the day, the name of the interval is irrelevant.  The age equivalency is also irrelevant. The only relevant criteria are the properties of the rock and the hydrocarbon saturation within it.  Those will determine the economics of the play.

TMS Core
I believe that the silica-richness of the TMS-East along with the increased calcareous content in the southern portion of the TMS-East will be key properties driving the success in this region of the play.  The clay richness historically experienced in certain areas of the play might have been incorrectly and broadly extrapolated over a very large region.

"Shale-gas and shale-oil plays are not necessarily strictly 'shale' plays as hybrid system - those systems with mixed lithofacies present - appear to be the most productive.  Strictly speaking shale is defined by particle size, but in shale-gas plays it is more important to know mineralogy as well as having clay speciation." 
Dan Jarvie, Worldwide Geochemistry LLC

I'm working on a comparison of the TMS to the Eaglebine (Madison, Grimes, and Brazos Cty, TX) and the Eagle Ford of Burleson County, Texas.  This might be the best analog for the TMS if one is required.  The Eagle Ford of south Texas stands alone.  Using the rock properties and lithology of the south TX Eagle Ford as an analog for any areas of the TMS is inaccurate and misguided.

I hope that the play works from Texas to Mississippi.  It would be a great boom for my home state.  Seeing oil booms occur in areas with poor economies is always a great thing.  For reasons of simplicity and consistency, this blog will continue to refer to the shale across the entire state as the TMS.

3 comments:

  1. Should the high resistivity area have greater saturation - more oil- than the low resistivity area?

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  2. FM,
    Read this:
    http://www.ameliaresources.com/documents/tuscaloosatrend/Amelia%20Resources%20LLC%20WEBSITE%20Tuscaloosa%20Marine%20Shale%20RESISTIVITY%20DISCUSSION%20Mar%202011.pdf

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  3. Kirk, my wife and I have an interest in the drilling activity in the southwest-central part of Louisiana, specifically the Justiss site near Vernon Parish. The last 3 or 4 scout reports indicate they have temporarily abandoned drilling and are awaiting a core analysis. I believe they have a 9000+ foot vertical hole. My question is can it take this long (over 3 weeks now) for a core analysis? Or is that code for some other reason drilling hasn't proceeded? They are reporting a 58 day drilling operation so far. Can I ask for your comments based on what they are reporting? Thanks...

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