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Naturally fractured reservoirs

Case study: Malay Basin


Maerten, L., Legrand, X., Castagnac, C., Lefranc, M., Joonnekindt, J.-P. and Maerten, F., 2019, Fault-related fracture modeling in the complex tectonic environment of the Malay Basin, offshore Malaysia: An integrated 4D geomechanical approach. Marine and Petroleum Geology, 105, 222-237.


  • Client: Petronas Carigali
  • Location: Malay Basin, offshore Malaysia
  • Main goal: 4D natural fracture modeling
  • Geology: Oligo-Miocene clastic reservoirs
  • Tectonic: Inverted basin, extension, contraction, strike-slip


  • Data analysis and interpretation
  • 3D model reconstruction and quality control
  • 3D model restoration over time (Dynel3D or CASSINI)
  • 3D paleo-stress models from 3D model over time (Petrel DFN or ARCH)
  • Discrete fracture networks over time constrained by paleo-stress (Petrel DFN)

Other applications using similar methodology

This workflow for natural fracture modeling can also be applied to:
  • Geothermal energy
  • Gas/CO2 storage
  • Nuclear waste disposal
  • Water reservoir

Main outcomes

3D model building
The main data on salt cavern are:

    • The complete fault network is used in the geomechanical simulations.

    • The 3D model (volume) is built and meshed (tetras) honoring the complexity of the interpreted structure.

    • Eroded parts have been added based on geological informations as they are needed for the 3D restoration (Dynel3D or Cassini) over time.
3D restoration over time
    • Full sequential 3D restoration (Dynel3D or Cassini) over time showing the evolution of the basin ranging from the Cretaceous to Oligocene extension to the late Miocene contraction creating a basin inversion.

    • Left-lateral displacement is also inferred from the 3D restoration along the main bounding fault.

    • The geometry of each restoration step can be used to constrain forward geomechanical simulations (Petrel NFP or Arch).
Observed natural fractures versus modeled fractures along wells
    • Comparison of rose diagrams between observed and computed (Petrel NFP or Arch) opening mode fracture (joints) developed during the N156° Cretaceous-Oligocene extension.

    • Comparison of rose diagrams between observed and computed shearing mode fractures (faults) developed during the N174° late Miocene contraction.

    • If there is a good fit between observed and computed fractures along the offset wells, the confidence will be higher for modeling natural fractures in the entire reservoir volumes.
3D paleo-stress fields over time and DFN
    • Modeled (Petrel NFP or Arch) normalized intensity trend for opening fracture type (joints) during the the N156° Cretaceous-Oligocene extension.

    • Modeled normalized intensity trend for shear fracture type (faults) during the N174° late Miocene contraction.

    • Complete fracture network (Petrel DFN) generated over time using modeled paleo-stress fields.
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