I do not know what additional information you want me to read.
The reason I think the laws of thermo don’t apply here as it doesn’t “appear to be a closed system 30k below the earths crust.
If you can draw a circle (sphere) around all of the components, that system can be evaluated as a closed system.
The entropy of a system is not going to decrease over time forming fewer, higher energy state molecules of longer hydrocarbon chains.
But there is no reason to debate the theory. The practical application of heat and pressure on hydrocarbon molecules are already in practice in modern refineries. Multiple different systems use heat and pressure to create smaller, not larger hydrocarbons. Use the link above to learn more. If you want more detail I can chase you down some more information.
sorry the link i posted did not come across.
here it is.
http://www.eurekalert.org/features/doe/2005-08/drnl-tsf082205.php