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Fractured reservoir modelling

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Main critical points

Fracture porosity evaluation Matrix - fracture exchange factor Equivalent permeability evaluation

Interaction between fractures at different scale

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Different scale fractures

Faults and main brittle lineaments can be important oil paths during the production phase, but can also anticipate breakthrough of water and/or gas at the wells

Intermediate scale fractures usually connect the fracture network to the wells and represent the drainage fracture system

Microfractures represent the storage (together with matrix porosity, if any)

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Discrete Fracture Network (DFN) models and on the simulation of hydrocarbon flow within the fracture system by means of a finite element single phase simulator

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The ENI Suite

(Golder packages)

FRED (Fractured Reservoir Evaluation and

Development)

Model Construction

DFN generation

Properties assignment

DFN analysis

Grid construction (FredMesh)

Results visualization

MAFICOIL

Single Phase Flow Simulation

K_Comp, SIGMA_BLOCK

Single Phase Flow Simulation

FRACA (Beicip/IFP package)

DFN simulation available tools

The software development is

carried out by the FRED

Consortium, which is

sponsored by the following

companies:

Marathon Oil Company

ExxonMobil Corporation

Enterprise Oil -> Shell

ENI Agip Division

Norsk Hydro

Golder Associates

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The workflow An overview

Available data

Production data

Evaluation of static DFN models

Dynamic model

Static DFN final model

Production data

Evaluation of static DFN model

Ranking of conceptual models

UPSCALING

Optimization

phase

Optimization

phase

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enables us to face each kind of fractured reservoir and to build reasonable and successful models (both dual or single porosity and permeability).

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3D Model Petrel/

Earthvision

Property

model.

Petrel

Fracture network

conceptual model

FRED/SIBYLFRAC

Flow sim. within

fracture network

MAFICOIL /WILMA

Seismic interpret.

Structural model

Reservoir layering

Fracture potential maps

Seismic attributes maps

Fracture properties from core

Fracture properties from imaging log

Production logs and tests

Fracture properties from outcrop and/or

seismics

Simulation Grid

Petrel/Eclipse/Sure

Eclipse/Sure 2 models

Fracture Analysis

AFRODITE

Stress field map (Poly3D)

Upscaling

Grid_K, -Block

Software chain

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The workflow Data integration

Available data

Production data

Evaluation of DFN static models

Dynamic model

Static DFN final model

Production data

Evaluation of static DFN model

Ranking of conceptual models

UPSCALING

Optimization

phase

Optimization

phase

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Conceptual model

Conceptual model refers to a schematisation of reality that describes the main features of the fracture system that control hydrocarbon flow behaviour

the geological drivers .

The choice of a sound conceptual model, and hence the geological driver, enables us to distribute fractures in a sensible way, also in the area not checked by the wells

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Geological Drivers

Qualitative and quantitative information related to geological

characteristics of the field.

They are used as trend to distribute to the whole field:

the fracture network

curvature map

258000 262000 266000 270000 274000 278000 282000 286000 290000 294000

3748000

3749000

3750000

3751000

3752000

3753000

3754000

3755000

3756000

3757000

3758000

3759000

3760000

3761000

fracture

intensity map

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Layering driven

Homogeneus Faults driven

Mixed

Advanced Modeling Techniques CONCEPTUAL MODELS