Reverse circulation directional and horizontal drilling using concentric coil tubing

A method of drilling a directional or horizontal wellbore in a hydrocarbon formation, comprising:

• providing a concentric coiled tubing drill string having an inner coiled tubing string, said inner coiled tubing string having an inside wall and an outside wall and situated within an outer coiled tubing string having an inside wall and an outside wall, said outside wall of said inner coiled tubing string and said inside wall of said outer coiled tubing string defining an annulus between the coiled tubing strings;
• connecting a bottomhole assembly comprising a directional drilling means, said directional drilling means having a drill bit and a downhole motor or an air hammer for operating the drill bit, to said coiled tubing drill string so that the bottomhole assembly is in fluid communication with the coiled tubing drill sting;
• delivering drilling medium through one of said annulus or inner coiled tubing string to said downhole motor or air hammer for operating the drill bit to form said directional or horizontal wellbore;
• and
• extracting exhaust drilling medium through said other of said annulus or inner coiled tubing string.