Print this pageNew Kinetic Method for Modeling Oil Generation
Longjiang Wang, Colin Barker
An extended kinetic method for modeling oil generation has been developed.
The method can be used to calculate the amount of oil generated by a 
source
rock, the amount migrated out of that source rock, and the expulsion efficiency.
It can also be used to establish the time of oil generation and migration and to
evaluate the evolving thermal maturity of the organic matter in the source rock.
The method incorporates a mass balance of all of the organic materials in a
source rock. It treats the kerogen in the source rock as two parts, one
convertible and the other nonconvertible. On heating, the convertible part of
kerogen transforms only to hydrocarbons, and the nonconvertible part either
remains unchanged (forming a carbon residue) or forms nonhydrocarbons (water,
carbon dioxide, etc). Unlike other proposed models, the new method does not
require a knowledge of the initial amount of organic matter in a source rock in
order to model oil generation. The input data are derived solely from a study of
the rock as it is today. Two assumptions are made in developing the method: (1)
oil generation can be described by a group of first-order parallel reactions and
(2) the total amo nt of oil that can be generated from a source rock is a
constant. The input data required for the model include the amount of bitumen
derived from dry pyrolysis (S1), the amount of kerogen pyrolysate (S2)
also derived from dry pyrolysis, the kinetic parameters (E and A) of the
kerogen, and the geothermal history of the source rock
.
AAPG Search and Discovery Article #91022©1989 AAPG Annual Convention, April 23-26, 1989, San Antonio, Texas.