SEPARATE WELL SPACING SYSTEM SAGD BASED ON GRADIENTS Russian patent published in 2017 - IPC E21B47/228 

FIELD: drilling soil or rock.

SUBSTANCE: invention relates to wells drilling, in particular, to plurality of wells drilling relative to each other monitoring facilities. Disclosed is well spacing system for electromagnetic spacing between first and second wells, containing tool, including: electric current source; at least, two electrodes arranged along tool axis, in which, at least, one electrode is emitter electrode and, at least, one electrode is return electrode, wherein electric current source is electrically connected to emitter electrode; and magnetic gradiometer, located along tool axis, intended for magnetic gradient detecting, induced by current flow flowing in conducting element in one of wells. At that, magnetic gradiometer is separated from electrodes by, at least, one insulator.

EFFECT: technical result of invention is increasing accuracy of magnetic gradient detecting due to minimizing current effect to magnetic gradiometer.

32 cl, 20 dwg