Patent ID: 11965415
Assignee: WELL INTERCEPT AS
Field: Civil engineering (Other fields)
Classification: CPC E  G | IPC E  G

Claim 0:
1. A method of extending a borehole for a well in a subsurface of the Earth, the method comprising the steps of:
(a) providing a rotary drill string in the borehole, wherein the rotary drill string includes a bottomhole assembly, and the bottomhole assembly includes at least one tubular or sub and a drill bit connected to an end of the tubular or sub;
(b) injecting current into the subsurface using at least one electrode disposed on the tubular or sub, thereby generating current in a casing of another well which is located a distance away from the borehole of the well, wherein the electrode is supplied with electrical power from a power source at surface, and the tubular or sub has a length uphole of the electrode that is non-conductive or electrically insulated from the subsurface surroundings and a length downhole of the electrode that is nonconductive or electrically insulated from the subsurface surroundings, for localized injection of current from the electrode into the subsurface, and wherein return electrical current from the subsurface is returned from downhole of the electrode through at least one part the drill bit, or through walling of the tubular or sub, in electrical coupling with the subsurface;
(c) detecting at least one component of a magnetic field which is associated with the current generated in the casing, using at least one sensor disposed on a length of the rotary drill string between the electrode and the drill bit or a length through which electrical current is returned;
(d) obtaining data from the sensor for determining either or both the proximity and direction to the other well;
(e) advancing the drill string into the subsurface based upon the obtained data to extend the borehole, and
(f) simultaneously, rotating the drill string to drill a section of the borehole and injecting current into the subsurface.