GR-Temp-CCL GTC43C Tool is mainly used for depth correction and leakage detection. This tool integrates three parameters of CCL, Gamma Ray & Temperature, and can be connected with other GOWell logging tools including MFC (Multi-finger Caliper Tool) for combination logging.
GTC43C is mainly comprised of the reference power supply circuit, MCU control circuit, CCL circuit, Gamma circuit, transmission circuit, and wellbore temperature circuit.
NATURAL GAMMA RAY MEASURING PRINCIPLE
The sensor of natural gamma section consists of PMT and sodium iodide crystal, and the working principle is shown in the figure below. This sensor detects the rays of luminescent substance
excited by the GR rays. PMT is comprised of photocathode, photoanode, dynode and some accessional resistors.
WELLBORE TEMPERATURE MEASURING PRINCIPLE
Wellbore temperature measurement circuit uses a PT100 platinum thermal resistor which is linearly responsive with the ambient temperature.
CCL MEASURING PRINCIPLE
CCL section is made up of induction coil, magnetic steel and amplifier. The induction coil is located between the four magnetic steels. When the tool meets the casing collar while it’s moving in the casing, the magnetic field strength in the coil changes correspondingly to the change of the magnetic flux surrounding magnetic objects in order to generate induction voltage.