Dolomitization of a carbonate platform can occur at different times and in different diagenetic environments, from synsedimentary to deep burial settings. Numerical simulations are valuable tools to test and select the model that, among different hypotheses compatible with field and geochemical data, best honour mass balance, kinetic and thermodynamic constraints. Moreover, the simulation can predict the distribution of the dolomitized bodies in the subsurface and evaluate porosity changes; valuable information for the oil industry. This study is the first attempt to reproduce and investigate the compaction dolomitization model. The diagenetic study of the Jurassic carbonate basin and palaeohigh system of the Po Plain indicates that the carbonates of the palaeohighs were dolomitized by basin compaction fluids. The main goal of the simulations is to evaluate the origin and evolution of the dolomitizing fluids and to provide insights regarding the distribution of the potential reservoir-dolomitized bodies in the Po Plain. The modelling process is subdivided into two steps: basin modelling and reactive transport modelling. The SEBE3 basin simulator (Eni proprietary) was used to create a three-dimensional model of the compacting system. The results include compaction fluid flow rate from the basin to the palaeohigh, compaction duration and a determination of the total amount of fluid introduced into the palaeohigh. These data are then used to perform reactive transport modelling with the TOUGHREACT code. Sensitivities on dolomite kinetic parameters suggest that dolomitization was an efficient process even at low temperatures, with differences mainly related to the dynamics of the process. Fluid composition is one of the main constraints, the sea water derived compaction fluid is proven to be efficient for dolomitization due to its relatively high Mg content. Simulations also confirmed that permeability is the most important factor influencing fluid flow and, consequentl
Application of numerical modelling to a case of compaction-driven dolomitization: A jurassic palaeohigh in the Po plain, Italy
Biagi S;Gherardi F;Gianelli G
2010
Abstract
Dolomitization of a carbonate platform can occur at different times and in different diagenetic environments, from synsedimentary to deep burial settings. Numerical simulations are valuable tools to test and select the model that, among different hypotheses compatible with field and geochemical data, best honour mass balance, kinetic and thermodynamic constraints. Moreover, the simulation can predict the distribution of the dolomitized bodies in the subsurface and evaluate porosity changes; valuable information for the oil industry. This study is the first attempt to reproduce and investigate the compaction dolomitization model. The diagenetic study of the Jurassic carbonate basin and palaeohigh system of the Po Plain indicates that the carbonates of the palaeohighs were dolomitized by basin compaction fluids. The main goal of the simulations is to evaluate the origin and evolution of the dolomitizing fluids and to provide insights regarding the distribution of the potential reservoir-dolomitized bodies in the Po Plain. The modelling process is subdivided into two steps: basin modelling and reactive transport modelling. The SEBE3 basin simulator (Eni proprietary) was used to create a three-dimensional model of the compacting system. The results include compaction fluid flow rate from the basin to the palaeohigh, compaction duration and a determination of the total amount of fluid introduced into the palaeohigh. These data are then used to perform reactive transport modelling with the TOUGHREACT code. Sensitivities on dolomite kinetic parameters suggest that dolomitization was an efficient process even at low temperatures, with differences mainly related to the dynamics of the process. Fluid composition is one of the main constraints, the sea water derived compaction fluid is proven to be efficient for dolomitization due to its relatively high Mg content. Simulations also confirmed that permeability is the most important factor influencing fluid flow and, consequentlI documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
