In the Oil and Gas industry, a well test is the execution of a set of planned data acquisition activities to broaden the knowledge and understanding of hydrocarbons properties and characteristics of the underground reservoir where hydrocarbons are trapped. The test will also provide information about the state of the particular well used to collect data. The overall objective is identifying the reservoir’s capacity to produce hydrocarbons, such as oil, natural gas and condensate.
There are many flavours of well tests and various ways to categorize test types by its objectives, however two main categories only by objectives, these are productivity tests and descriptive tests. There are four basic well test types: potential tests, daily tests, productivity tests, and gas oil ratio tests.
Test objectives will change throughout the different phases of a reservoir or oil field, from the exploration phase of wildcat and appraisal wells, through the field development phase and finally through the production phase, which may also have variations from the initial period of production to improved recovery by the end of the field life cycle time.