Inverse modelling to test seismic resolution of carbonate reservoirs
The objective of this study was to determine the resolution of the seismic tool in exploration for hydrocarbons in deep seated carbonate settings, thereby creating a better basis for predicting possible carbonate reservoir rocks. The two dimensional seismic modelling approach presented is a combination of forward modelling by raytracing and inverse modelling by a global optimisation method called simulated annealing. The combined method was tested on the Zechstein carbonate-evaporite platform interval, Southern Jylland, Denmark. Thin sequences, with thicknesses between five and ten metres in this setting, may be detected in the seismic data, when they are interbedded in rather homogeneous sequences and the acoustic impedances are known accurately. The critical point in the exploration for hydrocarbon-bearing Z2 carbonate sequence is the delineation of the overlying Z2 anhydrite. This thin anhydrite may be detected in seismic data down to thicknesses of around seven metres. The forward seismic modelling was tested on the Upper Cretaceous and Lower Tertiary chalk interval, Danish Central Trough. Sequences with thicknesses of ten metres in this setting may be detected as long as the acoustic impedances are increasing downwards.
Bibliographic Reference: EUR 13311 EN (1991) 88 pp., MF, ECU 4
Record Number: 199110022 / Last updated on: 1994-12-02
Original language: en
Available languages: en