Modelling method for forming a model simulating multilithologic filling of a sedimentary basin
AssigneeInstitut Francais du Petrole
InventorDidier Granjeon
Life of this patent
Estimating the term…
Abstract
A method for forming a 2D or 3D diffusive type model allowing simulation of multilithologic filling of a sedimentary basin over geologic periods. The model is based on the numerical simulation of the evolution of a sedimentary basin, from the past to the present, in a series of time intervals. In each time interval, three major phenomena interact and are numerically modelled: basin deformation, sediment supply and transportation of these sediments in the deformed basin. To model sediment transportation, long-term permanent transportation (creeping, slow diffusion process, etc.), short-term transportation (due to rain and flood) and catastrophic transportation (notably due to cliff collapse) are taken into account using an exponential water velocity model.
Claims6
A method for forming a diffusive type deterministic model for simulating multilithologic filling of a sedimentary basin, comprising:
- from known field data relative to an architecture of the basin and measured data or seismic data, forming a set of input data relative to an accommodation available through subsidence and eustasy, to a supply of fluvial or marine sediments and transportation thereof, and to physical parameters of lithologies, by an iterative process involving gridding the basin into grid cells of regular dimensions, modelling according to an explicit finite-volume scheme with constant time intervals, to simulate flow of each lithology deposited on each grid cell;
- and
- comparing simulation results with the data and modifying the set of input data step by step by inversion;
- and wherein for each time interval and for each lithology modelling by deterministic equations respectively
- a) a mean of a transportation processes acting on a permanent and continuous basis for a longer term, b) a mean of transportation processes acting on a permanent and continuous basis for a shorter term, and c) a mean of a transportation processes acting in a catastrophic way for a term less than the shorter term;
- and
- determining a resulting stratigraphy of the basin by accounting for the mass conservation.
Dependencies are inferred from the claim text.