Components of a downhole integrated well management system, and its method of use, can be deployed through tubing, a liner, or casing in existing wells without the need to deploy new pipe or remove and re-install pipe in the well. The system can seal the flow of hydrocarbon fluid and re-direct it into the claimed internal flow control module which, in embodiments, comprises a mandrel comprising one or more ports providing fluid communication between the interior of the mandrel and the outside of the mandrel and corresponding controllable port covers and/or seals that are adapted to open, partially open, or fully close a corresponding port; a flow controller; one or more sensor modules adapted to monitor a predetermined set of activities in a well; one or more communications module; and one or more power electronic modules. A surface module may be present and adapted to generate and transmit commands to the flow control modules and receive information from them.