Catagenesis (geology)

This article is about the term used in petroleum geology. For the term used in biology, see Catagenesis (biology).

Catagenesis is a term used in petroleum geology to describe the cracking process which results in the conversion of organic kerogens into hydrocarbons.

Theoretical reaction

This chemical reaction is believed to be a time, temperature and pressure dependent process which creates liquid and/or gaseous hydrocarbon Hc from primary kerogen X and can be summarised using the formula:

X_0 \rightarrow Hc + X(t)

where X0 is the initial kerogen concentration and X(t) is the kerogen concentration at time t.

It is generally held that the dependence on pressure is negligible, such that the process of catagenesis can be given as a first-order differential equation:

\frac{dX}{dt} = - \kappa X

where X is the reactant (kerogen) and κ is the reaction rate constant which introduces the temperature-dependence via the Arrhenius equation.

Important parameters

Several generally unrecognized but important controlling parameters of metamorphism have been suggested.[1]

Future Work

A great deal of future research is required to isolate the parameters which are most significant for inducing the Catagenetic process. Future work in the field will involve the following:

For example, while it was once assumed that catagenetic processes were first-order reactions, some research has shown that this may not be the case.[1]

See also

References

  1. 1 2 Price, Leigh C. (1997). "Minimum Thermal Stability Levels and Controlling Parameters of Methane, As Determined by C15+ Hydrocarbon Thermal Stabilities". Geologic controls of deep natural gas resources in the United States (USGS Bulletin 2146) (USGS): 139–176. Retrieved 2006-10-10.
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