DOWNHOLE GRADIOMETRIC RANGING UTILISING TRANSMITTERS AND RECEIVERS HAVING MAGNETIC DIPOLES Russian patent published in 2018 - IPC E21B47/09 

FIELD: measurement technology.

SUBSTANCE: present invention relates to downhole ranging, and in particular to a ranging device using transmitters and receivers with magnetic dipoles that analyse gradiometric data to determine and track the relative position of multiple wellbores. Method drilling a first wellbore which comprises an elongated conductive body. Deploying at least two magnetic dipole transmitters and at least four magnetic dipole receivers in a second wellbore. Inducing current along the first wellbore using the transmitters which results in a magnetic field being emitted from the first wellbore. Receiving the magnetic field using said receivers, wherein a gradient field is measured in a radial direction along the second wellbore. Using said gradient field to determine distance between the first and second wellbores.

EFFECT: disclosed is a method for analysing gradientometric data to determine and track the relative position of multiple wellbores.

21 cl, 11 dwg