PSI - Issue 6

A. Sidelnik / Procedia Structural Integrity 6 (2017) 316–321

319

Sidelnik Angelina// Structural Integrity Procedia 00 (2017) 000 – 000

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Figure 3. Discretization of the fault surface by triangular elements; observation points on the reference surface [2] Based on these parameters, the results of the inversion of paleotectonic stresses are visualized, where the values of Ṙ are plotted along the abscissa and ϴ — on the ordinate. Each point on this graph corresponds to one iteration (figure 2). Thus, we are able to determine the most probable direction of the tectonic driver, which contributed to the formation of current fault tectonics. Since displacements and deformations are calculated for each observation point (on the reference surface), it is possible to build maps of displacement and deformation fields. Changing the values on the calculated maps indicates that there are discontinuities that are not used in the original set of input data. The result of calculating the inversion model of paleostresses is a map of fault tectonics of the investigated site. Example of the determination of fault tectonics by the method of stress inversion Figure 4 shows an example of a map of fault tectonics within the N oil field by reconstructing paleotectonic stresses. Discontinuities 1-7 are defined in a multi-iterative way. The orientation of the tectonic driver contributing to the formation of this fault system is 71- 157 ° with the prevailing strike-slip regime (figure 5). The discontinuities obtained as a result of calculating the inversion model are compared with the structures received from the coherence cubes A, B, and C in the target interval. The most conspicuous similarity of the patterns identified on the displacement maps was noted when mapping the displacement field maps and slices of the RGB coherence cubes (figure 6).