Design and tests of a borehole radar for oil well prospecting

Based on the operational principles of ground penetrating radar (GPR) and the practical demanding of well prospecting, we designed an integrated borehole radar system which is assembled by antennas, transmitter, receiving system, and ground data processing sections. The transmission signal of this system is nanosecond, and the frequency of echo signal is high. It requires that, when the real-time sampling method is adopted, the conversion rate of A/D converter should be greater than 1 GHz. Therefore, we used an equivalent time sampling method. A borehole radar system was assembled by above mentioned components and tested in an actual oil well. The obtained data was processed and compared with that obtained by conventional logging instruments. Well coherent results were obtained. It proved this borehole radar system is able to identify the formation of abnormal points and different layers. Moreover, the detection range of the radar system, is longer than 5 m, is much better than that of the conventional logging instruments. It convinced that this system has foreseeable potential in oil well prospecting.