Drawdown / Buildup Test Type

Pressure drawdown tests are conducted by producing the well at a known rate, or sequence of rates, while measuring changes in pressure with time. Data from drawdown tests can be very noisy. These tests are considered when the economic environment requires a minimum loss of production time.

Pressure buildup tests are conducted by producing the well, and then shutting it in while measuring changes in pressure with time. Ideally, the flow preceding the shut-in would at least be long enough for the rates to stabilize. The quality of data obtained from buildup tests is far superior to that of drawdown tests because the rates are stable (zero). When analyzing data from buildup tests, it is valuable to analyze the drawdown and buildup data.