Application of Complex Approach to Risk Assessment for the Development of Pre-Fasila Reservoir in the Caspian Sea

Abstract

Complex approach to risk assessment is crucial especially if we deal with an offshore greenfield which development plan is hovering on the verge of profitability. The paper describes the algorithm and some outputs of application of the modern simulation technologies for assessment of the risks associated with the development of one of the Caspian offshore fields. The carried out risk assessment is based on multi-realization calculations including geomodeling, reservoir simulation and integrated modeling of fluid flow in wells and gathering system. Several types of variables affecting geovolumes and fluid flow are used to estimate uncertainties. The neighboring hydrocarbon field, where pre-Fasila formation has been under development for more than 20 years, is included into the model because its hydrodynamic connection with the studied field is in question. Markov Chain Monte Carlo technique is applied to get a posterior distribution of the future reservoir production. The calculation resulted in the conclusion that two offshore platforms should be installed at the middle and south-eastern parts of the field. This conclusion respects the risk defined by two main sources of uncertainty, the impact of which varies in different parts of the field. The applied approach enables quantitative risk assessment to be made in acceptable time, thus helps to make transparent and informed decisions and improves the project management efficiency.