METHODS AND APPARATUS FOR WIRELINE DRILLING ON COILED TUBING

摘要

Apparatus for drilling an underground borehole, comprising: - a tubular c onveyance system (18) including an electric cable and a supply of drilling f luid, the supply of drilling fluid being arranged in use to pump fluid from the surface down the inside of the tubular conveyance (18) so as to return t o the surface via the annulus between the outside of the tubular conveyance (18) and the borehole; - a drilling system (20) comprising an electrically p owered pump (28) and a drilling motor (22), the pump (28) being arranged in use to pump fluid from the borehole outside the drilling system (20) up thro ugh the inside of the drilling system (20); - a connector (30) connecting th e drilling system (20) to the tubular conveyance system (18), through which the pump (28) and motor (22) are connected to the electric cable, and - a fl ow diverter at which flow down the inside of the tubular conveyance system ( 18) is diverted into the annulus, and flow up the inside of the drilling sys tem (20) is diverted into the annulus.