Patent ID: 11891858
Assignee: COREALL AS
Field: Civil engineering (Other fields)
Classification: CPC E | IPC E

Claim 9:
10. A method for changing between drilling and coring modes of an apparatus for combined drilling and coring operations in a wellbore, wherein said apparatus comprises a core drilling assembly with a coring drill head, an outer tubing for conveying forces to the drill head, an inner tubing with an upper end connected to a bearing assembly and a lower end adapted for receiving a core sample, wherein changing between modes while drilling comprises:
activating or deactivating closure elements that are connected to the core drilling assembly at the lower end of the core drilling assembly and below an opening of the inner tubing, between an open or closed position for opening or closing access to the inner tubing and where the closure elements are provided with embedded cutting implements for cutting a core material when in a closed position, and
wherein activation and deactivation of the closure elements are performed with a lifting device for controlling the position of the inner tubing along the longitudinal axis of the core drilling assembly.