Surface-to-Borehole TFEM Data Acquisition System Development and Field Test
G. Yu, Z. He, G. Wang and L. Zhang
Event name: 81st EAGE Conference and Exhibition 2019 Workshop Programme
Session: WS11 Reservoir Characterization and Monitoring from Inversion and Joint Inversion of Seismic and Non-seismic Methods
Publication date: 03 June 2019
Info: Extended abstract, PDF ( 1.29Mb )
Price: € 20
A surface-to-borehole time-frequency domain EM (TFEM)data acquisition system has been developed and a successful field test was conducted in the Liaohe Oilfield of China. The field test has successfully acquired downhole 3-component magnetic field and vertical electrical field surface-to-borehole EM data the first time using a 3 km long surface dipole current source at two source locations. The first long dipole current source was placed in the redial direction of the borehole and 3 km away from the wellhead, and the second dipole current source was placed in the redial direction of the borehole and 3.5 km away from the wellhead. The dipole current source injected square wave current into the subsurface to generate the underground TFEM signal. A newly developed 4-level borehole TFEM receiver array was used to record surface-to-borehole TFEM data from the depth of 1,000 m to 1,800 m in the borehole. Each level of borehole TFEM receiver contains a 3-component time domain induction coil package installed in the center of receiver tool and two electrodes are located at each end of the receiver tool with a spacing of 10 m. The surface-to-borehole TFEM data show characteristics of subsurface formation electromagnetic properties and changes at different depth.