FIBER OPTICAL CONTROL OF CURRENT FOR ELECTROMAGNETIC RANGING Russian patent published in 2018 - IPC E21B7/04 E21B47/228 G01V11/00 

FIELD: measuring equipment.

SUBSTANCE: long-range system for the wellbore and the method used between the first and second well bores are proposed, wherein the system comprises an electromagnetic field pickup located in the wellbore of the second well, an electrically conductive casing in the wellbore of the first well, an electric current source, which creates an electric current in the conductive element, and a fiber-optic sensor located near the conductive element. Flow of electric current along the conductive element leads to the appearance of a magnetic field, which is measured by means of a measuring transducer. Fiber-optic sensor contains a core sensitive to the magnetic field in which it is located. Sensitive core changes the optical properties of the optical waveguide receiving the shape of the sensor, these modified optical properties being applied to determine the magnitude of the electrical current at the sensor location.

EFFECT: magnitude of the current and the measured magnetic field can be used to determine the distance between the trunks of the first and second wells.

29 cl, 7 dwg