Method for structure model building
A method for generating a plurality of structural models for a geological setting involves identifying a poorly imaged portion of an input seismic data set. A set of geologically valid kinematic base models are selected to define a kinematic evolution scenario. A correspond set of kinematic base model parameters is defined for the models. A structural model is generated for both a well-imaged portion of the seismic data and the poorly imaged portion. A misfit between the input horizons and the and the modeled horizons is calculated and steps are repeated for a predetermined number of iterations to produce a best-fit model. The steps are repeated then to produce a plurality of best-fit models of geologically plausible solutions for the geological setting. The method is particularly suitable for complex geological settings.
1. A method for generating a plurality of structural models for a geological setting, the method comprising the steps of:
(a) providing a seismic data set for the geological setting, the data set having a well-imaged portion and a poorly imaged portion;
(b) identifying a region of the poorly imaged portion of the seismic data set;
(c) providing input horizons for the well-imaged portion of the seismic data set;
(d) defining a kinematic evolution scenario by selecting a set of geologically valid kinematic base models;
(e) defining a set of kinematic base model parameters for the kinematic base models;
(f) generating a structural model with horizons for the well-imaged portion and the poorly imaged portion of the geological setting based on the set of kinematic base model parameters;
(g) calculating a misfit between the input horizons and the horizons for the structural model;
(h) running steps (f) and (g) for a predetermined number of iterations to produce a best-fit model;
(i) repeating steps (d) to (h) to produce a plurality of best-fit models of geologically plausible solutions for the geological setting; and
(j) ranking the plurality of best-fit models.
2. The method of claim 1 , wherein the set of geologically valid kinematic base model parameters is selected from the group consisting of fault propagation to fault slip ratio, fault slip, fault tip position, fault dip angle, trishear angle, folding zone boundary angles, and combinations thereof.
3. The method of claim 1 , wherein the poorly imaged portion is a seismic wipeout zone.
4. The method of claim 1 , wherein step (e) further comprises:
providing a set of geologically valid kinematic base model parameter ranges; and
randomly generating the set of geologically valid kinematic base model parameters within the geologically valid kinematic base model parameter ranges for a predetermined number of seeds.
5. The method of claim 1 , wherein an initial set of values in step (e) are determined by forward modelling experiments to yield the set of geologically valid kinematic base model parameters.
6. The method of claim 1 , wherein step (h) is conducted with a particle swarm optimization.
7. The method of claim 1 , wherein step (j) is conducted by ranking the misfits, by probabilistic density of model geometries, by probabilistic density of model styles, and combinations thereof.