Part of Well & Reservoir Surveillance and one of the Subsurface E&P Disciplines, related to measuring

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well volumetric flow rate and wellbore pressure in

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one or few selected wells

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and analysing pressure-rate correlation.

Unlike production analysis which normally covers a time period from few months to many years, well tests are rather short and normally take from few hours to few weeks.

The quantitative interpretation is based on:

pressure diffusion model with a purpose of dynamic reservoir properties analysis
well completion model with a purpose of Leak Detection

There are different ways to classify the well tests.

One way is to split well tests into two major categories:

Pressure Tests	Flowrate Tests
DST – Drill Stem Test

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	SBT – Separator Bulk Test
WFT – Wireline Formation Test	Surface Multiphase Flowmeter
SGS – Static Gradient Survey	Downhole Multiphase Flowmeter
PTA – Pressure Transient Analysis

The other way is to split well tests by the location where the measurements are taken and the well completion status:

Surface Well Tests	Subsurface Well Tests
	Open-Hole Well Tests	Cased-Hole Well Tests
Surface Flowmeter	DST – Drill Stem Test	Downhole Flowmeter
SBT – Separator Bulk Test	WFT – Wireline Formation Test

MRST – Multirate Step Test

SGS – Static Gradient Survey
		PTA – Pressure Transient Analysis

Third way is to split well tests by number of wells involved:

Single-Well Tests

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	Multi-Well Tests

Multiwell Routine Fitting

Flowrate Testing

PIST

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– Pressure Interference Step Test

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(as version of PTA)
SGS – Static Gradient Survey	PICT – Pressure Interference Pulse Test (as version of PTA)
DST – Drill Stem Test
WFT – Wireline Formation Test

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Drawdown Test (DD) (as version of PTA)
Injection Test (INS) (as version of PTA)
Build-up Test (BUS) (as version of PTA)
Fall off Test (FOS) (as version of PTA)
MRST – Multirate Step Test (as version of PTA)
SPT – Self-Pulse Test (as version of PTA)