A simple yet accurate approach to integrated asset modeling of a complex deepwater dry gas field in the east coast of India is presented here that involves the use of a multi-tank material balance model.
The field shown here has wells having multi-zonal completion with multiple contacts and perched water. Matching well-wise watercut with multiple water breakthrough events while simultaneously obtaining a good match of declining well pressures has historically been a challenge in this field. In this paper a novel and robust solution to this problem of simultaneous water cut and pressure matching has been presented through the combined use of fractional flow curves and analytical water breakthrough matching. Issues with the modeling of the pressure drop of pipelines and wells which are starting to liquid load and are flowing in the unsteady-state regime have also been addressed in this IAM model.
A multi-tank MBAL model was built using partially connected tanks which was enhanced with the use of compaction correction to both permeability and inter-tank transmissibility. Well-wise fractional flow curves were used for water rate prediction. Wells, chokes and pipelines were modeled and history matched to field data in GAP. Pressure drop calculations were calibrated to loading curves generated from OLGA. A description of the history matching and production forecasting through the IAM model and its use for evaluation of production optimization strategies such as the use of velocity strings has been shown.