The fact of the matter is OW that hydrocarbon generation is not the primary driver of over pressure so it follows that the over pressure is primarily independant of GOR as per the item link Laz posted.
http://www.searchanddiscovery.com/documents/2013/41093cander/ndx_cander.pdf
The clear statement is made:
"Therefore, whereas retained petroleum properties can be linked closely to thermal stress, creation and
retention of over-pressure is not strictly due to petroleum generation and a broader, basin-scale interpretation is required in order to define regions where revenue generation will be highest."
"Because it is often the foreland phase of rapid subsidence and
burial that catalyzes both disequilibrium compaction and source-rock maturation, the
generation of petroleum and over-pressure are often coeval, and their effects on reservoir pressure, effective stress, permeability, and reservoir deliverability can be DIFFICULT TO DIFFERENTIATE."
Several authors have proposed that most of the over-pressure in shale source rocks was created by petroleum generation. Basin modeling performed in this study suggests that
petroleum generation can account for SOME of the over-pressure within the Eagle Ford Shale gas and liquids fairway (as measured in psi above hydrostatic).
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" However,
MUCH of the regional over-pressure was generated from DISEQUILIBRIUM COMPACTION ..................."
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"The reservoir pressure we see in the Eagle Ford today is the result of
how the pressure was created and how it was PRESERVED after burial."
And as we well know:
"Mobility of shale liquids and, thus, revenue flow are also
STRONGLY a function of reservoir pressure."
"....the sweet spot (i.e., the most profitable part) of the Eagle Ford Shale is found where
the least viscous liquid phase and the most oil-rich vapor phase occur at HIGHEST RESERVOIR PRESSURE."
An additive question (that have circumstantial implications) I have too OW.
If the GOR was that much different at the FB sweet spot why would Dave be bothering to permit a new pad for a potential horizontal pilot well/s ?
Perhaps just preparation ???
It follows that my assertion would be that yes there may be a difference in the GOR to that expected but that difference is not going to be of a magnitude size that will effect the project financials to such a degree that could not be adjusted for in the well array structure or using different drilling technology.
And another potential additive is that they may well have underestimated the effect of the volatile vapour phase liquids which could possibly account for the higher GOR. This would be a major boost to how the well might perform.
Perhaps I'm too glass half full eh OW ?
If there was potential for a massive difference in GOR I would think they would have failed fast at this location. But then that's jmo.
d.
(20min delay)