Well test (oil and gas)

In the petroleum industry, a well test is the execution of a set of planned data acquisition activities.

Data gathered during the test period includes volumetric flow rate and pressure observed in the selected well.

The main objective in the exploration phase is to assess the size of a reservoir and state with a given certainty whether it has the properties for commercial exploitation and shall contribute to accounting for available reserves.

It is important to know the individual contributions to account hydrocarbon material balance and for well monitoring and reservoir management.

[3] The separator divides the flow from the well into the streams of individual products which typically are oil, gas and water, but may include natural-gas condensate.

Flow rate, water cut, GOR and other parameters for the test system can deviate from production separators.

This approach allows the incorporation of other modes of measurements such as spin-cuts (manual water cut readings) and dynamometer card based inferred rates.

DSTs involve lowering a series of tools into the well to temporarily isolate the reservoir and collect samples of the fluids.

Example Well Testing Package. Shown: Choke Manifold, Well Testing Separator, flare stack, surge tank and Wellhead.
Simplified process flow diagram. A plant is receiving a multi phased flow of oil and gas from many wells via a manifold. Flow from one well only may be taken to the test separator (shaded). The test separator has the feature to separate gas and water from the oil, and to have each component measured, under different conditions.