Based on analysis of the principle of time domain electromagnetic method（ TEM）

the design of the magnetic induction coil is simplified. Using PIC microcontroller as control core

the system integrates signal generation unit

receiving and processing unit and a data transmission unit. Field test results show that the system can effectively detect the casing external formation information

accurately distinguish the oil-water interface and the effective radial detection distance can reach 0. 8 m. The system has many advantages such as convenient control

long detection distance

reliable performance

high integration and low power consumption. It provides a new method for the water flooding monitoring.