Modélisation des hétérogénéités lithologiques à l'échelle du réservoir pétrolier en milieu marin et fluviatile

Bruno Leflon. ( 2005 )
Institut National Polytechnique de Lorraine

Abstract

When modelling a petroleum reservoir, well data are very useful to model properties at a sub-seismic scale. Petrophysical properties like porosity or permeability are linked to the rock-type. Two methods based on well data have been developed to model facies. The first one is used to model marine carbonates deposits. The geometry of sedimentary layers is modelled through a special parameterisation of the reservoir similar to Wheeler space. The time parameter is defined along the well paths thanks to correlations. The layer thickness is then extrapolated between wells. A given relationship between facies and bathymetry of sedimentation makes it possible to compute bathymetry along the well paths. Bathymetry is then extrapolated from wells and a reference map using the concept of accommodation. The model created this way is stratigraphically consistent. Facies simulation can then be constrained by the computed bathymetry. The second method describes a novel approach to fluvial reservoirs modelling. The core of the method lies in the association of a fairway with the channels to be simulated. Fairways are positioned so that all data are taken in account ; they can be stochastic if unknown or explicitly entered if identified on seismic data. A potential field is defined within the fairway. Specifying a transfer function to map this potential field to thickness results in generating a channel inside the fairway. A residual component is stochastically simulated and added to the potential field creating realistic channel geometries. Conditioning to well data is obtained by applying the inverse transfer function at the data location to derive thickness values that will constrain the simulation of residuals.

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BibTeX Reference

@PHDTHESIS{Leflon2005a,
    author = { Leflon, Bruno },
     title = { Modélisation des hétérogénéités lithologiques à l'échelle du réservoir pétrolier en milieu marin et fluviatile },
      year = { 2005 },
    school = { Institut National Polytechnique de Lorraine },
  abstract = { When modelling a petroleum reservoir, well data are very useful to model properties at a sub-seismic
scale. Petrophysical properties like porosity or permeability are linked to the rock-type. Two methods
based on well data have been developed to model facies.
The first one is used to model marine carbonates deposits. The geometry of sedimentary layers is
modelled through a special parameterisation of the reservoir similar to Wheeler space. The time parameter
is defined along the well paths thanks to correlations. The layer thickness is then extrapolated
between wells. A given relationship between facies and bathymetry of sedimentation makes it possible to
compute bathymetry along the well paths. Bathymetry is then extrapolated from wells and a reference
map using the concept of accommodation. The model created this way is stratigraphically consistent.
Facies simulation can then be constrained by the computed bathymetry.
The second method describes a novel approach to fluvial reservoirs modelling. The core of the method
lies in the association of a fairway with the channels to be simulated. Fairways are positioned so that all
data are taken in account ; they can be stochastic if unknown or explicitly entered if identified on seismic
data. A potential field is defined within the fairway. Specifying a transfer function to map this potential
field to thickness results in generating a channel inside the fairway. A residual component is stochastically
simulated and added to the potential field creating realistic channel geometries. Conditioning to well data
is obtained by applying the inverse transfer function at the data location to derive thickness values that
will constrain the simulation of residuals. }
}