Apparatus and system for power conversion. The magnetic device is designed to be subcutaneously implanted in the patient at the implanted injection port, and the magnetic detector is movable externally along the patient’s body to establish an injection position at the patient’s skin in front of the implanted injection port where the local magnetic field emitted by the magnetic device is detected by the magnetic detector. The method provides the ability to choose the order in which the subterranean interval sections surrounding a wellbore are treated with fluid. The thermal image was acquired by a thermal imaging system. The grooves are configured and sized to allow a movement of the second frame within the first frame comprising a linear movement component and a tilting movement component.