Probabilistic evaluation of oil resources on block 12, Iraq

Key words: technical and economic evaluation of exploration assets, probabilistic reserves calculations, Monte-Carlo method, Iraq Fourth Licensing Round.

In 2012 Bashneft JSOC won the exploration, production and development service contract for Block 12, Iraq. The paper describes the methodology applied for assessing the probability of an oil discovery on this block, as well as probabilistic estimates of the possible reserves volume. The combined use of the Monte Carlo method is described, both for the volumetric parameters that determine the possible range of the recoverable reserves and for the probability factors that determine the chance of geological success for each potentially productive formation. Special attention is given to the interdependency of the probability factors and the correct handling of its effect on potential oil reservoirs in different formations within a single geological structure (trap) and on oil reservoirs within the same formation but in different traps.