In turbidite settings, channel sand bodies stack laterally and vertically as a function of turbidite story confinement degree: higher the confinement degree, higher the vertical-to-horizontal movement ratio. LOSCs also evolve by progressive lateral and/or downdip migration. The most common method used to simulate such channel sequences is by stochastic object modelling. While populating the observed fairway with realistic forms, it fails ensuring consistency between the individual channels. Labourdette (2008) has proposed to model the most recent channel using a B-Spline. A B-spline is a piecewise curve with each component being a curve of degree p. B-splines are parameterized by a suite of control points, thus offering a very simple and powerful way to design complex shapes with lower degree polynomials. Labourdette (2008) then showed that the transition from one to another channel could be achieved by simply moving the control points of the B-Spline. He also stated the laws determining this movement as being parabolic towards the fairway's centreline and upstream. In a more recent paper, Labourdette and Bez (2010) have established simple mathematical relationships between the lateral and vertical displacements of the control points and the confinement degree of the story. In this paper, we show how this theory has been turned into a pseudo-genetic algorithm to efficiently simulating a LOSCs sequence. We describe which parameters can be made random variables and we show how, by adequately choosing the input values, we can generate a wide range of types of stacked sequences, from the less to the most confined. Finally, it is also shown how conditional well can be taken into account. Various examples from real studies will be used to illustrate the performance of the algorithm. References
Labourdette R. (2008). ?LOSCS? Lateral Offset Stacked Channel Simulations: Towards geometrical modelling of turbidite elementary channels. Basin Research 20(3), pp. 431?444.
Labourdette R. and Bez M. (2010). Element migration in turbidite systems: Random or systematic depositional processes? AAPG Bulletin 94 (3), pp. 345-368. |
