I have a question about the upper versus lower zones at Heron for any geo's out there who would care to elaborate. Basic physics would tell me that if you take a 4000m slice through the earth's crust then the pressure per unit area (in the radial direction) would increase the lower you go (at least this is true for water and air, but perhaps not solid formations). So my question is that assuming the pressure is related this way in rock formations can you relate porosity inversely to pressure? This is, is gas is more easily liberated from a solid that is under less stress through pressure?
The second question I have is about the CO2 content, found to be 35%. CO2 is a much lighter gas then any other hydrocarbon that would be encountered in a reservoir (except methane, ethane and propane and their derivatives however these gases are less soluble in water and are more bulky i.e. have a larger solvent accessible surface area than CO2). Ok so with that background to CO2 my question is: considering the relatively small size of CO2 and its concomitant greater mobility in the solid rock is it more or less likely to be found in formations that are closer to the surface? My worry is that given the high 35% CO2 found in the lower zone is it more or less likely to find a greater percentage of CO2 in an upper zone. This is obviously a complicated question because the relative mobility of CO2 should be related to the relatively porosity of the material (average pore size in the rock).
So any clarifications from a geo on these issues would be great.
Thanks.
MEO Price at posting:
16.5¢ Sentiment: Hold Disclosure: Held
