Research on the high temperature calibration of the electromagnetic damping generator applied to the rotary steerable system

The Electromagnetic Damping Generator (EDG) used for petroleum exploration is faced with the problem of high local temperature during its downhole work. To avoid the damage to its internal circuit caused by high temperature, the key EDG circuit is required to be heat-resistant based on the electromagnetic induction principle and the current heating effect. First of all, the working condition with the maximum heating power was figured out after studying the heating power characteristics of EDG. Then the multi-field coupling model of the temperature field, electromagnetic field and structure of the damper, as well as its iterative analytic model were established to identify the relationship between the temperature rise of the key location of the damper part and its working time in the downhole environment and the room-temperature experimental environment, which provided data support for EDG optimization design. Finally, a EDG prototype was developed, and the test bench was set up by replacing the load with resistors to verify the accuracy of the iterative analytical model. The results showed that the temperature value calculated by the model well fit the experimental value. Therefore, the downhole operation reliability of the EDG and the safety of corresponding bench tests are guaranteed, which has certain guiding significance for EDG optimization design and its experimental study.