Method and Apparatus for Directional Well Logging

A drilling system, comprising:

• a conductive tubular in a wellbore in a first formation having a first resistivity, the conductive tubular comprising:
• a drill bit that axially extends the wellbore,
• an electric current driving tool having an insulated gap that generates a current along the conductive tubular, and
• a magnetometer that measures inside the conductive tubular a direction and a magnitude of a magnetic field induced by the generated current;
• the drilling system further comprising:
• a MWD tool transmits the measurements to the surface;
• a surface control computer system that determines the presence of an adjacent formation through which the wellbore does not pass based on a non-zero magnitude of the measured magnetic field inside the conductive tubular;
• and
• a steerable system that receives a driller command based on the determined presence of the adjacent formation through which the wellbore does not pass and steers the drill bit in a given trajectory in the formation based on the driller command.