Recent Advances in Reactive Transport Modeling of Carbonate
and Clastics
Diagenesis
and Reservoir Quality Prediction
Yitian Xiao and Gareth Jones
ExxonMobil Upstream Research Company, Houston, TX
Diagenesis
is a critical control on
carbonate
and clastics reservoir quality. Reactive transport modeling is an emerging technology with the capability to simulate coupled fluid flow and diagenetic reactions to predict spatial and temporal variations in porosity and permeability. We applied reactive transport modeling to investigate several styles of
carbonate
and clastics
diagenesis
:
- Early
diagenesis
in four hydrological zones (vadose, freshwater, mixing, and saline) in an isolated
carbonate
platform;
- Dolomitization and anhydrite cementation in a brine reflux system;
- Geothermal convection and burial
diagenesis
in a salt-buried isolated platform;
- Fault-induced hydrothermal fluid flow and illitization; and
- Formation damage associated with water injection and artificial
diagenesis
.
Adopting a sensitivity analyses approach, we examined how key natural
variables, such as climate, sea level, temperature, fluid salinity and
composition, and porosity/permeability heterogeneity impact different styles of
diagenesis
. By linking fundamental geochemical processes to predict reservoir
quality we have significantly improved our understanding of previous conceptual
diagenetic models and paradigms. Our novel approach suggests that reactive
transport models, if sufficiently integrated with traditional methods and
calibrated with field data, have the potential to significantly improve our
ability to predict
carbonate
and clastics reservoir quality.