Abstract: High productivity core drilling systems include a drill string, an inner core barrel assembly, an outer core barrel assembly, and a retrieval tool that connects the inner core barrel assembly to a wireline cable and hoist. The drill string comprises multiple variable geometry drill rods. The inner core barrel assembly comprises a non-dragging latching mechanism, such as a fluid-driven latching mechanism that contains a detent mechanism that retains the latches in either an engaged or a retracted position. The inner core barrel assembly also comprised high efficiency fluid porting.

Abstract: High productivity core drilling systems are described. The system includes a drill string, an inner core barrel assembly, an outer core barrel assembly, and a retrieval tool that connects the inner core barrel assembly to a wireline cable and hoist. The drill string comprises multiple variable geometry drill rods. The inner core barrel assembly comprises a non-dragging latching mechanism, such as a fluid-driven latching mechanism that contains a detent mechanism that retains the latches in either an engaged or a retracted position. The inner core barrel assembly also comprised high efficiency fluid porting. Accordingly, the drilling system significantly increases productivity and efficiency in core drilling operations by reducing the time required for the inner core barrel assembly to travel through the drill string. Other embodiments are also described.