Monday, June 23, 2014

Geology Matters

I was entertained by an infamous Baton Rouge landman in July, 2011 when he told me, "It's a shale play. Geology doesn't matter!!".
Well maybe the time has come for the TMS geology to start to reveal itself.  

In the past, I've presented a list of "model wells" that meet these three criteria: 1) per stage proppant level of 425-600k 2) a lateral length of at least 5000' and 3) a landing zone in the bottom 70' of the TMS.  If all three of these criteria are met, a good result has occurred.  

Last week a result of 815 boepd was released for the Goodrich Nunnery 12H-1.  The "financial quants" appeared to be disappointed. With a net pay of 75', this result is not only expected, but good for the pay thickness.  At a TVD-SS of -10800', this well with improved initial rate and lower costs will present positive economics in the months ahead.  The main "takeaway" from the result is that every location is not "geologically" equal.  Thickness, depth, pressure, natural fractures, GOR, TOC, porosity, and permeability will all come into play.  I have presented the Passey Log Method many times in my presentations.  It is my conclusion that this analysis method works very well in this play and presents consistent trends.  Isopaching D-Log-R will define very clear trends in pay thickness.  The GDP Lewis 30-19H-1 has 110' of net pay and had an initial potential of 1450 boepd.  

Most importantly, initial potentials are not very good for assessing future well results.  Yes, it gives you an initial rate, but the first 30 days of production provides a much better "initial metric". Ultimately the decline curve over the first year will be most significant.


In the coming weeks, we will see another geological contrast with the GDP SLC 81H-1 and the GDP Beech Grove 94H-1.  The net pay in the Beech Grove of 95' will not likely compare in result with the SLC 81H-1 (157').  Through time, the thickness will be added as a 4th dimension to the "model wells" criteria.  The Nunnery 12H-1 is a good example of a well that met the first three criteria, but the thickness of porous, naturally fractured, organic rock makes a difference.

The chart below compares the results from five recent wells.

9 comments:

  1. any info on the Trinidad rig on Enterprise road?

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  2. mark, I don't have any info on the rig

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  3. Please label wells in graph above. How much does logged feet of pay play

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  4. In the ultimate value of a well when fracturing only goes so far?

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    1. Kirk:

      I believe a 5th dimension (depth) will also become a very relevant factor to be included in the very important and critical dimensions you have already identified.

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  5. Landman, not sure if I understand your question. The natural fractures contribute a significant amount of oil in the early years then the rock matrix kicks in for the longer life. Both fractures and porosity are important.

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  6. JHP,
    Yes depth is important. Deeper depth is more costs, but higher pressure, GOR, and calcite %. Time will tell how those "shake out"

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  7. Should increased depth with its higher pressure,GOR and calcite equal more extensive natural fractures and better porosity?

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    1. FM, an increase in calcite could increase fractures as is seen in the Eagle Ford shale. Porosity would not likely increase with a change in those parameters

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