@article {Simula.simula.1498,
	title = {A Numerical Framework for Modelling Folds in Structural Geology},
	journal = {Mathematical Geosciences},
	volume = {45},
	number = {3},
	year = {2013},
	month = {April},
	pages = {255-276},
	publisher = {Springer},
	abstract = {A numerical framework for modelling folds in structural geology is presented. This framework is based on a novel and recently published Hamilton-Jacobi formulation by which a continuum of layer boundaries of a fold is modelled as a propagating front. All the fold classes from the classical literature (parallel folds, similar folds, and other fold types with convergent and divergent dip isogons) are modelled in 3D space as continua defined on a finite difference grid. The propagating front describing the fold geometry is governed by a static Hamilton-Jacobi equation, which is discretized by upwind finite differences and a dynamic stencil construction. This forms the basis of numerical solution by finite difference solvers such as fast marching and fast sweeping methods. A new robust and accurate scheme for initialization of finite difference solvers for the static Hamilton-Jacobi equation is also derived. The framework has been integrated in simulation software, and a numerical example is presented based on seismic data collected from the Karama Block in the North Makassar Strait outside Sulawesi.},
	keywords = {Workshop},
	author = {Hjelle, {\O}yvind and Steen A. {Petersen} and Are Magnus {Bruaset}}
}
@inproceedings {Simula.simula.1284,
	title = {A Data-Restoration and Model-Reconstruction Workflow for Simultaneous Seismic Interpretation and Model Building},
	journal = {EAGE 74th Conference \& Exhibition, Extended Abstracts},
	year = {2012},
	publisher = {EAGE},
	type = {Annual},
	abstract = {A workflow for simultaneous seismic interpretation and model building is presented. The workflow consists of two sequences. A first, in which a depth seismic section is gradually altered, by reverse and mainly structural processes, in order to restore the seismic section of the target at the time of deposition. In the second sequence a distribution of properties representing the target becomes subject to the normal version of the previous reverse geological processes, now ordered forward in time. The final property distribution is the reconstruction of the present day distribution. The method has many interesting advantages compared to present day workflows. It is fast and the model becomes geologically feasible. During the successive data-Restoration the impact of faults, deformation and compaction is gradually removed by invoking the inverse of these processes. The section looks \&ldquo;younger\&rdquo; and e.g. stratigraphical interfaces appears easier to interpret. Few - 10 times less than normal - and simpler surfaces are needed to represent the target no matter how much it was compartmentalised originally. Having the restoration processes and their order in place the model- Reconstruction is done very fast executing the normal processes forwardly. Additional mainly depositional and erosional processes can be added during reconstruction.},
	author = {Steen A. {Petersen} and Hjelle, {\O}yvind and Hustoft, Steinar and Houbiers, Marianne and Rasmussen, Rasmus}
}
@inproceedings {Simula.SC.418,
	title = {Earth Recursion, an Important Component in Sharead Earth Model Builders},
	journal = {Proceedings from the 70th EAGE Conference \& Exhibition},
	year = {2008},
	note = {The paper received Best Paper Award.},
	publisher = {Society of Petroleum Engineers and European Association of Geoscientists and Engineers},
	type = {Conference},
	address = {Rome},
	abstract = {The concept of Earth Recursion is introduced to solve critical problems of Shared Earth Model builders especially related to their capability to express the geological evolution. The recursive approach turns out to be very efficient when addressing apparently diverse questions like natural {\textquotedblleft}aging{\textquotedblright}, property depth trends, incorporation of externally defined property distributions, faults within volumes and structural restoration. The concept is implemented in the Compound Earth Model builder by StatoilHydro. It is shown how the original expression for spatial distribution of properties can be written as a recursive sequence. This revision forms the basis for the implementation of Earth Recursion in the builder and demonstrated by construction of a complex property distribution reflecting the interference of on-lapping features, normal faulting and compression.},
	author = {Steen A. {Petersen} and Hjelle, {\O}yvind}
}
