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.