Changes

Understanding the underlying geology of sedimentary basins is often hindered by the existence of complex structures and/or lack of data, leading to highly uncertain models, and thus exploration/operational difficulties. For that, subsurface dynamic structural models are critical for constructing an understanding of the structural evolution of a basin of interest. For instance, tectonic controls such as faults and subsidence/uplift play a significant role in altering the subsurface geology, impacting petroleum system elements such as reservoir distribution and source rock burial depth. Dynamic restoration models as such can aid the understanding of petroleum systems processes, including hydrocarbon maturation, expulsion, migration and accumulation, and potentially present-day location of hydrocarbon fields.‎<ref name=Neumaier_2016>Neumaier, M. (2016). Structural Restoration and Basin and Petroleum Systems Modeling: Case Studies from the Monagas Fold and Thrust Belt, Venezuela and the Moroccan Atlantic Margin (Doctoral dissertation, Universitätsbibliothek der RWTH Aachen).</ref> Structural balancing and restoration combined make a good tool that can be used to validate structural models and predict untapped locations with more confidence in a geologically plausible manner.

Understanding the underlying geology of sedimentary basins is often hindered by the existence of complex structures and/or lack of data, leading to highly uncertain models, and thus exploration/operational difficulties. For that, subsurface dynamic structural models are critical for constructing an understanding of the structural evolution of a basin of interest. For instance, tectonic controls such as faults and subsidence/uplift play a significant role in altering the subsurface geology, impacting petroleum system elements such as reservoir distribution and source rock burial depth. Dynamic restoration models as such can aid the understanding of petroleum systems processes, including hydrocarbon maturation, expulsion, migration and accumulation, and potentially present-day location of hydrocarbon fields.‎<ref name=Neumaier_2016>Neumaier, M. (2016). Structural Restoration and Basin and Petroleum Systems Modeling: Case Studies from the Monagas Fold and Thrust Belt, Venezuela and the Moroccan Atlantic Margin (Doctoral dissertation, Universitätsbibliothek der RWTH Aachen).</ref> Structural balancing and restoration combined make a good tool that can be used to validate structural models and predict untapped locations with more confidence in a geologically plausible manner.

[[file:AlHawajAlQahtaniFigure1.jpg|thumb|300px|{{figure number|1}}3D restoration conducted on a faulted and folded layer (Sub-Andean Zone, Bolivia), showing a) the deformed state and b) the restored state. c) Distribution of maximum principal stress that resulted from the deformation in a.‎<ref name=Morettietal_2006>[12] Moretti, I., Lepage, F., & Guiton, M. (2006). KINE3D: a new 3D restoration method based on a mixed approach linking geometry and geomechanics. Oil & Gas Science and Technology, 61(2), 277-289.</ref>]]

[[file:AlHawajAlQahtaniFigure1.jpg|thumb|300px|{{figure number|1}}3D restoration conducted on a faulted and folded layer (Sub-Andean Zone, Bolivia), showing a) the deformed state and b) the restored state. c) Distribution of maximum principal stress that resulted from the deformation in a.‎<ref name=Morettietal_2006>Moretti, I., F. Lepage, and M. Guiton, 2006, KINE3D: A new 3D restoration method based on a mixed approach linking geometry and geomechanics: Oil & Gas Science and Technology, v. 61. no. 2, p. 277-289.</ref>]]

Structural restoration can be conducted in 2D and 3D models. As 3D applications help to quantify spatial distribution of deformation, 2D balancing and restoration can be used to validate interpretation at parts of the volume of interest, which can be edited before committing to the 3D workflow ([[:file:AlHawajAlQahtaniFigure1.jpg|Figure 1]]).  

Structural restoration can be conducted in 2D and 3D models. As 3D applications help to quantify spatial distribution of deformation, 2D balancing and restoration can be used to validate interpretation at parts of the volume of interest, which can be edited before committing to the 3D workflow ([[:file:AlHawajAlQahtaniFigure1.jpg|Figure 1]]).  

Several established techniques have been used as a basis for restoration workflow, which are:  

Several established techniques have been used as a basis for restoration workflow, which are:  

* Geometric Methods: Geometric balancing strives to balance one or more aspects of the geometry (e.g. horizon length, formation cross-sectional area).

* Geometric Methods: Geometric balancing strives to balance one or more aspects of the geometry (e.g. horizon length, formation cross-sectional area).

* Kinematic Modeling: Balancing and restoration utilize concepts of deformation kinematics and dynamics that are best visualized in forward modeling. Kinematic modeling reproduces the structural geometry as the structure moves (i.e. geometry-based kinematic models).

* Kinematic Modeling: Balancing and restoration utilize concepts of deformation kinematics and dynamics that are best visualized in forward modeling. Kinematic modeling reproduces the structural geometry as the structure moves (i.e. geometry-based kinematic models).

* Numerical Modeling: Numerical modeling provides a great advancement over geometric models whereby the physical properties of the formations can be modeled during the deformation. An example of such development in 2D modeling of fault-propagation folds is the trishear model that incorporates not only the strain in the hanging wall block but also that in the footwall block.‎<ref name=Erslev_1991>Erslev, E. A. (1991). Trishear fault-propagation folding. Geology, 19(6), 617-620.</ref> Three-dimensional trishear modeling followed after at the beginning of the 21st century.‎<ref name=Cristallinietal_2004>Cristallini, E. O., Giambiagi, L., & Allmendinger, R. W. (2004). True three-dimensional trishear: A kinematic model for strike-slip and oblique-slip deformation. Geological Society of America Bulletin, 116(7-8), 938-952.</ref>  

* Numerical Modeling: Numerical modeling provides a great advancement over geometric models whereby the physical properties of the formations can be modeled during the deformation. An example of such development in 2D modeling of fault-propagation folds is the trishear model that incorporates not only the strain in the hanging wall block but also that in the footwall block.‎<ref name=Erslev_1991>Erslev, E. A. (1991). Trishear fault-propagation folding. Geology, 19(6), 617-620.</ref> Three-dimensional trishear modeling followed after at the beginning of the 21st century.‎<ref name=Cristallinietal_2004>Cristallini, E. O., L. Giambiagi, and R. W. Allmendinger, 2004, True three-dimensional trishear: A kinematic model for strike-slip and oblique-slip deformation: Geological Society of America Bulletin, v. 116, no. 7-8, p. 938-952.</ref>  

* Geomechanical Modeling: Geomechanical modeling covers not only the geometric aspects but also the states of stress and strain that caused and accompanied the deformation by using, boundary, discrete and finite element modeling.‎<ref name=Masinietal_2011>Masini, M., Bigi, S., Poblet, J., Bulnes, M., Di Cuia, R., & Casabianca, D. (2011). Kinematic evolution and strain simulation, based on cross-section restoration, of the Maiella Mountain: an analogue for oil fields in the Apennines (Italy). Geological Society, London, Special Publications, 349(1), 25-44.</ref>

* Geomechanical Modeling: Geomechanical modeling covers not only the geometric aspects but also the states of stress and strain that caused and accompanied the deformation by using, boundary, discrete and finite element modeling.‎<ref name=Masinietal_2011>Masini, M., S. Bigi, J., Poblet, M. Bulnes, R. Di Cuia, and D. Casabianca, 2011, Kinematic evolution and strain simulation, based on cross-section restoration, of the Maiella Mountain: An analogue for oil fields in the Apennines (Italy), ''in'' J. Poblet and R. J. Lisle, eds., Kinematic evolution and structural styles of fold-and-thrust belts: Geological Society (London) Special Publication 349, p. 25-44.</ref>

[[file:AlHawajAlQahtaniFigure2.jpg|thumb|300px|{{figure number|2}}Suggested restoration workflow that is summarized as a flowchart (Modified after Petroleum Experts 2018).‎<ref name=Petroleumexperts_2018>Petroleum Experts. (2018). Best practices in 2D sequential restoration - Part 2. Edinburgh, Scotland, UK.</ref>]]

[[file:AlHawajAlQahtaniFigure2.jpg|thumb|300px|{{figure number|2}}Suggested restoration workflow that is summarized as a flowchart (Modified after Petroleum Experts 2018).‎<ref name=Petroleumexperts_2018>Petroleum Experts. (2018). Best practices in 2D sequential restoration - Part 2. Edinburgh, Scotland, UK.</ref>]]