Abstract: A magnetic hotspot detector is capable of locating magnetic hotspots in tubulars, such as tubulars for use downhole. A sensor array can include multiple sets of differential fluxgate magnetometers, each set comprising two non-differential fluxgate magnetometers arranged across the diameter of a tubular to be measured. As the tubular passes through the sensor array, fluctuations in magnetic field due to the movement of the tubular through the sensor array are measured to provide indication of the location of magnetic hotspots. To locate hotspots, a tubular can be passed through the sensor array or the sensor array can pass over the tubular.

Abstract: A well detection system includes a signal generator module and a detector module. Signal generator module is coupled to a well structure, and causes the well structure to emit a signal. The emitted signal is measured by the detector module. Based on measurements of the signal, the detector module can determine information pertaining to the source of the emitted signal and can, for example, determine the location of the well structure relative to the detector module.

Abstract: A well detection system includes a signal generator module and a detector module. Signal generator module is coupled to a well structure, and causes the well structure to emit a signal. The emitted signal is measured by the detector module. Based on measurements of the signal, the detector module can determine information pertaining to the source of the emitted signal and can, for example, determine the location of the well structure relative to the detector module.