DOWNHOLE GRADIOMETRIC RANGING FOR T-INTERSECTION AND WELL AVOIDANCE UTILISING TRANSMITTERS AND RECEIVERS HAVING MAGNETIC DIPOLES Russian patent published in 2018 - IPC E21B47/228 G01V3/26 

FIELD: meter reading.

SUBSTANCE: invention relates to the drilling of directed wells and can be used for drilling intersecting wells. In particular, disclosed is a method for downhole ranging, comprising: drilling a first wellbore, the first wellbore comprising an elongated conductive body; deploying at least two magnetic dipole transmitters and at least four magnetic dipole receivers in a second wellbore; wherein the dipole receivers comprise: two main receivers and two bucking receivers; using said bucking receivers to eliminate the direct signal emitted from said transmitters; inducing a current along the first wellbore using the transmitters that results in a magnetic field being emitted from the first wellbore; receiving the magnetic field utilising the main and bucking receivers, wherein a gradient field is measured; and utilising the gradient field to determine a distance between the first and second wellbores.

EFFECT: technical result is higher accuracy of determining the location of the well relative to the target.

22 cl, 10 dwg