Three-dimensional prediction of diagenesis in reservoirs.
in: Proc. 27th Gocad Meeting, Nancy
Abstract
In reservoir studies, a gap often exists between the geostatistical modeling of heterogeneities at deposition
time and flow simulation in the present-day reservoir grid: diagenesis transforms rock properties, and
could completely modify reservoir quality, especially in carbonate reservoirs. Besides the compaction effects
that are often implicitly accounted for in facies models, two phenomena modify rock properties: (1)
the dolomitization and dissolution of carbonate formations, and, (2) the cementation which reduces porosity
and permeability of both clastic and carbonate reservoirs. These rock modifications mainly originate
in chemical reactions involving water circulations through the sediments. These circulations of liquid predominantly
concern the permeation of meteoric water in emerged carbonate littorals and the migration of
fluids in fracture network or in fault damage zones. Therefore, the chemical diagenesis mainly depends (1)
on the capacity of original rocks to transmit fluids, and thus on their petrophysical properties and (2) on
the distance to fluid sources, being the emersion areas, the faults and fractures. We propose an innovative
approach to better constrain the quantitative prediction of diagenesis. Probabilities for each diagenetic rock
type are estimated by integrating well observations, sedimentological and lithological models, and structural
and mechanical information. Diagenetic rock types are then predicted by stochastic simulations using the
generated probability fields. This solution is applied to a faulted carbonate reservoir, and shows its ability to
overlay the effects of diagenesis onto facies models. The suggested approach improves the predictive power
of reservoir models by integrating important geological knowledge in reservoir descriptions.
Download / Links
BibTeX Reference
@inproceedings{P311_Kedzierski,
abstract = { In reservoir studies, a gap often exists between the geostatistical modeling of heterogeneities at deposition
time and flow simulation in the present-day reservoir grid: diagenesis transforms rock properties, and
could completely modify reservoir quality, especially in carbonate reservoirs. Besides the compaction effects
that are often implicitly accounted for in facies models, two phenomena modify rock properties: (1)
the dolomitization and dissolution of carbonate formations, and, (2) the cementation which reduces porosity
and permeability of both clastic and carbonate reservoirs. These rock modifications mainly originate
in chemical reactions involving water circulations through the sediments. These circulations of liquid predominantly
concern the permeation of meteoric water in emerged carbonate littorals and the migration of
fluids in fracture network or in fault damage zones. Therefore, the chemical diagenesis mainly depends (1)
on the capacity of original rocks to transmit fluids, and thus on their petrophysical properties and (2) on
the distance to fluid sources, being the emersion areas, the faults and fractures. We propose an innovative
approach to better constrain the quantitative prediction of diagenesis. Probabilities for each diagenetic rock
type are estimated by integrating well observations, sedimentological and lithological models, and structural
and mechanical information. Diagenetic rock types are then predicted by stochastic simulations using the
generated probability fields. This solution is applied to a faulted carbonate reservoir, and shows its ability to
overlay the effects of diagenesis onto facies models. The suggested approach improves the predictive power
of reservoir models by integrating important geological knowledge in reservoir descriptions. },
author = { Kedzierski, Pierre AND Durand-Riard, Pauline AND Caumon, Guillaume },
booktitle = { Proc. 27th Gocad Meeting, Nancy },
title = { Three-dimensional prediction of diagenesis in reservoirs. },
year = { 2007 }
}