Well definitions:
Source: Regulations relating to resource management in the petroleum activities (the Resource Management Regulations).
Appraisal well: exploration well drilled to establish the extent and size of a petroleum deposit that has already been discovered by a wildcat well.
Development well: a generic term for wells used for production of petroleum, production wells, injection wells and observation wells, and possible combinations thereof.
Exploration well: a well drilled in order to establish the existence of a possible petroleum deposit or to acquire information in order to delimit an established deposit. Exploration well is a generic term for wildcat and appraisal wells.
Injection well: a development well or test development well used for injection of gas, water or other medium.
https://www.npd.no/en/facts/wells/well-definitions/