Reducing Reservoir Model Uncertainties with Geostatistical Inversion: A Case Study for Block 1, Turkmenistan

The reservoir sands in Block 1, Offshore Turkmenistan, have high heterogeneity and uncertainty on the vertical and lateral continuity, distribution and fluid contact. In this study, both simultaneous and geostatistical seismic inversions have been carried out. Simultaneous inversion was carried out first to obtain a single model solution that best fits the seismic data, using all available set of well data, seismic wavelets and structural framework. While geostatistical inversion was performed after simultaneous inversion to derive multiple reservoir model scenarios that express such reservoir heterogeneity and uncertainty. This paper highlights the main steps taken to improve the predictability of major reservoirs in the main field via seismic conditioning as well as the use of geological constraints through geostatistical inversion. All the results were analysed to identify the high, mid and low cases representing the different level of uncertainties of the reservoir, which could then be used as input for future reservoir simulation, modelling and development.