Journal of Petroleum Geology, Vol.7,
No.1, pp.109-112, 1984
©Copyright 2000 Scientific Press,
A PROBLEM WITH ESTIMATING
ENERGY OF KEROGEN THERMAL MATURATION FROM CONNAN'S
TIME-TEMPERATURE RELATION IN OIL GENESIS
Charles E. Barker*
*U.S. Geological Survey, Box
25046, Denver Federal Center, Denver, CO 80225.
Connan's time-temperature relation in oil
genesis as derived from first-order reaction kinetics is
algebraically correct, but its application to natural petroleum
generation is invalidated by the assumption that the ratio of
initial kerogen concentration to degraded kerogen concentration
is constant from deposition to the initiation of intense oil
generation. The ratio can only remain constant if no reaction is
occurring and, therefore, Connan's data on "reaction
time" in petroleum generation (assumed to be the age of the
sediment) only measures the time elapsed since the system formed.
Thus, the widely cited pseudo-activation energy of 11-14
kcal/mole computed from Connan's equation for the start of oil
generation from kerogen is meaningless.