US Patent 7331394 Autonomous well intervention system

A self-contained well intervention system which can be deployed from a lightweight vessel and coupled directly to a wellhead is described. The system includes valve means for providing a suitable well barrier and sealing the intervention system to allow an emergency disconnect. Within the intervention system, a tool magazine is provided which contains at least one deployable intervention tool. The intervention system also contains a tool selection and deployment means based on a winch located in close proximity to the magazine and which is operable from the surface for selecting a particular tool from the magazine and for deploying the selected tool through the intervention system and the wellhead into the well. The tool magazine has a plurality of magazine pockets each of which may have a deployable tool therein. The tool selection and deployment means can be used to select and to join the selected tools together within the intervention system to form an intervention tool string which can be run into the wellhead so that a plurality of different operations can be performed within the well during an intervention.