1. n. [Well Completions]

The differential pressure that drives fluids from the reservoir into the wellbore. The drawdown, and therefore the production rate, of a producing interval is typically controlled by surface chokes. Reservoir conditions, such as the tendency to produce sand, may limit the drawdown that may be safely applied during production before damage or unwanted sand production occurs.

2. n. [Well Testing]

A decline in well pressure with time due to production.