Basement rock hybrid drilling

A method comprising:

• monitoring a permeability of a first portion of a borehole of a well while forming the borehole using a mechanical drilling apparatus including a drill bit for mechanical removal of material from within the borehole;
• monitoring a rate of penetration of the drill bit of the mechanical drilling apparatus;
• determining, based at least on the permeability of the borehole falling below a permeability threshold value and the rate of penetration of the drill bit of the mechanical drilling apparatus falling below a rate of penetration threshold value, to utilize a millimeter wave drilling apparatus including a waveguide configured for insertion into the borehole;
• and
• forming a second portion of the borehole utilizing the millimeter wave drilling apparatus in response to the determining.

A method comprising:

• monitoring a permeability of a first portion of a borehole of a well while forming the borehole using a mechanical drilling apparatus including a drill bit for mechanical removal of material from within the borehole;
• monitoring a hardness of a material present within the first portion of the borehole;
• determining, based at least on the permeability of the borehole falling below a permeability threshold value and the hardness of the material exceeding a hardness threshold value, to utilize a millimeter wave drilling apparatus including a waveguide configured for insertion into the borehole;
• and
• forming a second portion of the borehole utilizing the millimeter wave drilling apparatus in response to the determining.

A method comprising:

• monitoring a permeability of a first portion of a borehole of a well while forming the borehole using a mechanical drilling apparatus including a drill bit for mechanical removal of material from within the borehole;
• determining, based at least on the permeability of the borehole falling below a permeability threshold value, to utilize a millimeter wave drilling apparatus including a waveguide configured for insertion into the borehole;
• and
• forming a second portion of the borehole utilizing the millimeter wave drilling apparatus in response to the determining, wherein the millimeter wave drilling apparatus and the waveguide are operated to form the second portion of the borehole to a depth greater than a depth limit of the mechanical drilling apparatus,
• wherein the millimeter wave drilling apparatus and the waveguide are operated to form the second portion of the borehole to a depth greater than a depth limit of the mechanical drilling apparatus.