| The development of upscaling program with ALGMP method | Japan
Oil and Gas Development Consulting and Engineering Company, Japan Oil Engineering

When the reservoir pressure drops below the dew point pressure during the gas production from a gas condensate reservoir, liquid condensation will occur near the wellbore and can cause to decrease well gas productivity. This phenomenon is called “Condensate banking” and is a potential problem in a gas condensate reservoir.
In order to model this phenomenon in reservoir flow simulation, pressure decline in the vicinity of the well need to be reproduced by refining the simulation grid blocks around the wellbore. In addition, that simulation should be done using compositional reservoir simulator to evaluate complicated phase behavior. However, these approaches are not practical because they take huge amount of computation time.

INPEX Corporation developed the Adaptive Local-Global Multiphase Upscaling Method (ALGMP) to capture near-wellbore effects in coarse scale flow simulation models and has applied to the black oil reservoir. In this project, ALGMP was applied to the gas condensate reservoir with a black oil reservoir simulator instead of a compositional one. The program code which connects ALGMP algorithm with the commercial black oil simulator was developed, and was applied to the actual reservoir model. As a result, while the effect of condensate banking was evaluated very well, the computation time was considerably reduced. Our special kind of skills, such as the development of reservoir simulators in-house and deep knowledge of internal structures of commercial reservoir simulators, led to make this project successful.