Reservoir Modelling Strategies for Miocene Isolated Carbonate Platforms

Abstract

A generic strategy for modelling gas fields in Miocene isolated carbonate platforms leverages insights from over 20 analogue fields in the Central Luconia Province in Malaysia, some with 30+ years of development and production history. The strategy advocates customizing modelling efforts to answer the questions required to make business decisions at hand (decision-based modelling) while keeping the models as simple as possible (fit-for-decision models). Four presented examples vary from (1) a conceptual, scaled simulation model that is used to investigate various host tie-back options (screening development options—two examples), through (2) a static reservoir model with seismically constrained reservoir properties combined with a simulation that uses local multipliers to test the impact of key heterogeneities on well-placement options (development optimization), to (3) a full-field static and dynamic reservoir model that is matched to a long and detailed production history to accurately forecast late-field-life gas and water production (wells, reservoir, and facilities management). In combination with standardized work flows for reservoir property modelling, the strategy shifts the modelling focus from elaborate base-case models with uncertainty ranges to testing multiple scenarios that span the range of possible outcomes. The use of this generic modelling strategy has led to faster turnaround of subsurface work, enabling faster development and asset management decisions. Although the examples presented in this paper are specific to Miocene carbonates in Central Luconia, a similar strategy could be suitable for other geological settings.