Estimating the Depth of Stratigraphic Units from Marine Seismic Profiles Using Nonstationary Geostatistics
The object of this study is to build a three-dimensional (3D) geometric model of the stratigraphic units of the margin of the Rhone River on the basis of geophysical investigations by a network of seismic profiles at sea. The geometry of these units is described by depth charts of each surface identified by seismic profiling, which is done by geostatistics. The modeling starts by a statistical analysis by which we determine the parameters that enable us to calculate the variograms of the identified surfaces. After having determined the statistical parameters, we calculate the variograms of the variable Depth. By analyzing the behavior of the variogram we then can deduce whether the situation is stationary and if the variable has an anisotropic behavior. We tried the following two nonstationary methods to obtain our estimates: (a) The method of universal kriging if the underlying variogram was directly accessible. (b) The method of increments if the underlying variogram was not directly accessible. After having modeled the variograms of the increments and of the variable itself, we calculated the surfaces by kriging the variable Depth on a small-mesh estimation grid. The two methods then are compared and their respective advantages and disadvantages are discussed, as well as their fields of application. These methods are capable of being used widely in earth sciences for automatic mapping of geometric surfaces or for variables such as a piezometric surface or a concentration, which are not 'stationary,' that is, essentially, possess a gradient or a tendency to develop systematically in space.
- OSTI ID:
- 21064306
- Journal Information:
- Natural Resources Research (New York, N.Y.), Vol. 9, Issue 1; Other Information: DOI: 10.1023/A:1010165914840; Copyright (c) 2000 Plenum Publishing Corporation; Country of input: International Atomic Energy Agency (IAEA); ISSN 1520-7439
- Country of Publication:
- United States
- Language:
- English
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