A method for mapping underground sensors onto a network map may include obtaining a plurality of magnetic measurements from a plurality of sensors. The method may include using the plurality of magnetic measurements for determining a plurality of sensor locations in an initial network map. The method may include generating updated network maps from the perspective of each localized sensor. The method may include merging the updated network maps into a final network map, the final network map comprising a most accurate location for each sensor. The method may include determining inner localized sensors out of the plurality of sensors in the final network map. The method may include identifying the inner localized sensors as new base station anchors. The method may include mapping the inner localized sensors onto the final network map as new base station anchors.

A method for mapping underground sensors onto a network map may include obtaining a plurality of magnetic measurements from a plurality of sensors. The method may include using the plurality of magnetic measurements for determining a plurality of sensor locations in an initial network map. The method may include generating updated network maps from the perspective of each localized sensor. The method may include merging the updated network maps into a final network map, the final network map comprising a most accurate location for each sensor. The method may include determining inner localized sensors out of the plurality of sensors in the final network map. The method may include identifying the inner localized sensors as new base station anchors. The method may include mapping the inner localized sensors onto the final network map as new base station anchors.

A depth positioning method to position a production logging tool (1) and a measurement log in a hydrocarbon well (3) in production obtained by means of the tool, the depth positioning method comprises: generating (S1, S2, S3, S1′, S2′, S3′, S11, S12, S13) a set of magnetic measurements (MAG1, MAG) of a depth portion of the hydrocarbon well from a first passive magnetic sensor along the depth portion of the hydrocarbon well, the set of magnetic measurements comprising magnitude and/or direction measurements of the magnetic field that forms a characteristic magnetic field pattern representative of a surrounding magnetic environment of the hydrocarbon well all along the depth portion; comparing (S4, S4′, S14) the set of magnetic measurements (MAG1, MAG) to another set of magnetic measurements (MAG_R, MAG2), the other set of magnetic measurements being a reference set of magnetic measurements generated either by a same or similar passive magnetic sensor deployed and run in the hydrocarbon well earlier, or by a second passive magnetic sensor spaced from the first passive magnetic sensor from a defined distance (DS) deployed and run in the hydrocarbon well simultaneously; and determining (S4, S4′, S14) the maximum of correlation between the set of magnetic measurements (MAG1, MAG) and the reference set of magnetic measurements (MAG_R, MAG2), the maximum being related to identifiable characteristic magnetic field pattern over a part of the depth portion.

An instrumented cutter including a polycrystalline diamond table bonded to a substrate with a sensor, for monitoring the condition of the polycrystalline compact diamond table, embedded in the substrate. Further the instrumented cutter includes a wireless transmitter equipped with a power supply to power to the wireless transmitter.

An instrumented cutter including a polycrystalline diamond table bonded to a substrate with a sensor, for monitoring the condition of the polycrystalline compact diamond table, embedded in the substrate. Further the instrumented cutter includes a wireless transmitter equipped with a power supply to power to the wireless transmitter.

A unified mud-pulse (MP)-electromagnetic (EM) telemetry assembly and a downhole telemetry tool are provided including a downhole EM telemetry transmitter apparatus. The EM telemetry transmitter apparatus comprises a modulator configured to transmit at least one EM signal through transmission medium. The modulator comprises a first reactive circuit and a second reactive circuit, and a plurality of switches controlled by a controller to alternatingly switch the modulator between a first configuration and a second configuration. The EM signals are transmitted by passing one of the reactive circuits and bypassing the other reactive circuit.

Apparatus, systems, and methods for ranging operate to use a wireline active ranging system to initially determine a relative distance and relative direction from a first well (e.g., ranging well) to a second well (e.g., target well) and an EM azimuthal logging tool to maintain or adjust the distance from the target well while drilling the ranging well. Additional apparatus, systems, and methods are disclosed.

Apparatus, systems, and methods for ranging operate to use a wireline active ranging system to initially determine a relative distance and relative direction from a first well (e.g., ranging well) to a second well (e.g., target well) and an EM azimuthal logging tool to maintain or adjust the distance from the target well while drilling the ranging well. Additional apparatus, systems, and methods are disclosed.

Systems and methods for determining azimuth of a wellbore while drilling. A method of drilling a wellbore that includes rotating a drill bit to extend the wellbore into a subterranean formation. The method may further include measuring magnetic toolface with a first magnetometer while rotating the drill bit. The method may further include obtaining a cross-axial magnetic field measurement. The method may further include determining azimuth at a point in the wellbore using at least the magnetic toolface and the cross-axial magnetic field measurement. The method may further include using the azimuth as feedback in the drilling the wellbore.

Systems and methods for determining azimuth of a wellbore while drilling. A method of drilling a wellbore that includes rotating a drill bit to extend the wellbore into a subterranean formation. The method may further include measuring magnetic toolface with a first magnetometer while rotating the drill bit. The method may further include obtaining a cross-axial magnetic field measurement. The method may further include determining azimuth at a point in the wellbore using at least the magnetic toolface and the cross-axial magnetic field measurement. The method may further include using the azimuth as feedback in the drilling the wellbore.