Patent ID: 7307629
Filing Date: 2007-12-11
Classification: G01V,G06T

Abstract:
1. A method for the generation of a three dimensional fractal subsurface structure by Voronoi tessellation and computation of gravity response of such fractal structure, by generation of fractal subsurface structures and computation of a forward gravity response of such structure for delineation and modeling of an underlying anomalous object, said method comprising: (a) selecting Voronoi centers at a plurality of locations over a region of interest, the Voronoi centers being represented by x, y, z co-ordinates; (b) generating an initial model of a subsurface fractal geological object, having variation in a physical property in lateral and vertical directions; the initial model being generated by tessellating the Voronoi centers, and assigning values of physical property variations during generation of the model on the basis of pre-determined assumptions in the model; (c) assigning different discernable representations to regions in the model which have different physical properties to enable demarcation; wherein the fractal subsurface model is generated by a modified Voronoi tessellation technique which comprises modifying the Voronoi tessellation by using L wherein the computation of a gravity response due to a fractal subsurface generated by modified Voronoi tessellation is carried out by an analytical expression which comprises: (a) demarcating boundaries of regions having a different physical property in the tessellated region, the boundaries forming a polygonal shape in 2-dimensional space; Where S=+1 if p i is positive, S=−1 if p i is negative, W=+1 if m ‘Z’ is depth and ‘n’ is number of sides in the polygon, G is universal gravitational constant, ρ is the density of the tessellated regions; p q f m r r r i=is a subscript, which is used to select the next consecutive point on the surface of the body; where the effect of a common arm of the adjacent polygon is removed; (b) repeating the gravity response computation due to the polygon for all adjacent polygons of different physical properties using the demarcated polygon boundary; (c) adopting the process of gravity response computation for tessellated regions lying at different depths to obtain a response; (d) integrating the response using Simpson/Gauss quadrature formula at plurality of grid nodes overlain on the region of interest; and (e) creating a model of the underlying anomalous object.