3D Petroleum Systems Modeling of Eastern and Central Saudi Arabia
By
Mahdi Abu Ali1, Christof Keuser2, Bjorn Wygrala2, Dietrich Welte2
(1) Aramco, Dhahran, Saudi Arabia (2) IES, Julich, Germany
3 Dimensional Petroleum Systems Modeling (3D PSM) is an integral process
that describes and models petroleum migration
, dynamically and through geologic
time, from source to trap. It considers all petroleum system elements such as
source, reservoir, seal, trap,
migration
and timing of all key processes. In
contrast, conventional basin modeling is mainly concerned with hydrocarbon
generation within the source rock.
A 3D model was constructed for Eastern and Central Arabia that described
thermal and maturation histories of the Paleozoic geologic successions. This
model emphasized hydrocarbon generation and migration
histories from the
Silurian Base Qusaiba source rock to the Devonian Jauf and Permo-Carboniferous
Unayzah reservoirs.
Migration
of different hydrocarbon compound classes was
modeled using a compositional generation scheme for the Silurian Qusaiba source
rock.
Results show that Tertiary tilting of the basin has affected present-day
drainage areas. Several sensitivity runs were performed to test the influence of
certain petroleum systems elements such as reservoir, seal, source and migration
properties on the distribution and composition of hydrocarbons within the study
area. A 3D hybrid Darcy/Flowpath simulator was used to test different
migration
scenarios taking into account open and/or closed fault systems. Present-day
accumulations were compared with the simulation results to validate their
sensitivities.
The results demonstrate that 3D petroleum systems modeling technology, if well calibrated, provides an excellent exploration tool to predict distribution and type of petroleum occurrences. Once reservoir hydrocarbon compositions are reasonably predicted, the application of such a tool will witness a new era in petroleum exploration and development.