Print this pageDetermination of Kinetic Parameters Specific for a Given Source Rock: Optim Method
Philippe Ungerer, Pierre-Yves Chenet
The OPTIM method consists of 
processing
pyrolysis data in order to obtain an
optimized set of kinetic parameters which account for the kinetics of
hydrocarbon formation from the specific source rock considered. The basic
principles of the underlying kinetic model are the same as the Tissot and
Espitalie model, in which the number of parallel reactions has been increased.
The first way to use the OPTIM program is to use Rock-Eval pyrolysis data from a
unique immature kerogen sample at various heating rates. Additional data
obtained from autoclave pyrolysis may be integrated optionally. This way is
particularly adapted to early stages of basin exploration, when the source rock
is already identified but not sampled in the oil formation zone. As shown in
cases where the predi tions could be checked against well data, the model
optimized by this way is applicable to natural conditions with a reasonable
accuracy. The second way to use the program is to integrate pyrolysis data
from
several immature and mature samples of the type considered, together with the
thermal history of each sample. Such a use of the program is possible only when
the basin is already well explored and when the paleotemperatures do not suffer
high uncertainties. The advantage of the method is then to account explicitly
for the natural maturation process. Several application examples are presented
which show very important differences of behavior between various source rocks,
from a kinetic as well as from a quantitative viewpoint. Our method provides the
industry with an operational and r latively rapid tool in order to account for
these differences.
AAPG Search and Discovery Article #91038©1987 AAPG Annual Convention, Los Angeles, California, June 7-10, 1987.