Impact of Gravel-Pack Length for Effective Well Completion and Well Performance

Abstract

This work investigates the effect of variable gravel pack length on well performance. Field data were obtained on the well, fluid properties, reservoir and PROSPER used to developed a wellbore model in which gravel pack completion was installed. The well performance was initially determined at the completion without any sand control technique. With gravel pack installed, sensitivity analysis was done for different gravel pack length. Results reveals that without gravel pack completion, at a bottom hole flowing pressure of 14.7psig, the reservoir will deliver 15719.7 STB/day of oil which is the Absolute Open Flow Potential (AOF). The model predicts that with gravel pack completion installed, the reservoir will deliver 12706.4STB/day of oil across the gravel pack completion into the wellbore. The installation of gravel pack completion resulted in a percentage decrease of 19.169% in oil inflow into the wellbore. Assessment of the well inflow performance without gravel pack completion shows that the well will produce 10926.8 STB/day of oil at a flowing bottomhole pressure of 2551.38psig. The model predicts an oil rate of 8427.13STB/day at a flowing bottomhole pressure of 2330.38psig for the case with gravel pack completion installed. There was a downward shift intersection between the inflow and outflow performance curves as both gravel pack permeability and gravel length increases. Also, there was a corresponding decrease in oil production rate with large gravel length. Therefore, large gravel length should not be used as it will translate into a high pressure drop along the fluid conduction path and reduced the inflow into the wellbore.