With the advent of downhole permanent gauge reliable gathering of flowing bottomhole pressure is on the rise. This essential bottomhole reservoir data is subtracted from the reservoir average pressure to calculate pressure drawdown. The resulting drawdown is commonly used to estimate well productivity index. In this paper we demonstrate how drawdown can be used to generate a decline curve which is extrapolated to estimate future recovery potential.

We show in detail how this method is used to estimate future production performance by linearization of drawdown-time curve and drawdown-cumulative curve and thereafter extrapolate the resulting straight-lines into the future.

Keywords:
production control, upstream oil & gas, uptime ratio, drillstem testing, curve analysis, pressure drawdown decline curve analysis, bottomhole pressure, reservoir surveillance, cumulative production, cumulative uptime
Subjects:
Well & Reservoir Surveillance and Monitoring, Formation Evaluation & Management, Drillstem/well testing
Copyright 2012, Society of Petroleum Engineers
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