Patent RU-2738734-C1 (RU)
Inventor: Brekhov Evgenii Ivanovich
IPC: G01V1/16
Filed: 2020-03-12
Granted: 2020-12-16
Abstract: FIELD: measurement. 
     SUBSTANCE: invention relates to three-component downhole seismic detectors. Essence: seismometer includes in sealed housing (1) generator (2), first, second and third channels (3–5) receiving seismic signals; first, second and third analogue outputs (6–8) of the first, second and third channels (3–5) of receiving seismic signals, respectively; first, second and third inputs (9–11) of calibration of first, second and third channels 3–5 of receiving seismic signals, respectively. Each channel for receiving seismic signals includes housing (12), pendulum (13), first spring (14), an elastic first support (15), series-connected first capacitive displacement sensor (16), first amplifier-demodulator (17), first feedback unit (18) and first magnetoelectric transducer (19). Pendulum (13) is mechanically connected to first spring (14), with the elastic first support (15), to the first capacitive displacement sensor (16) and to the first magnetoelectric transducer (19). First capacitive displacement sensor (16), first spring (14), the elastic first support (15) and the first magnetoelectric transducer (19) are mechanically connected to housing (12). First capacitive displacement sensor (16) and first amplifier-demodulator (17) are connected to generator (2). Additionally, seismometer includes fourth, fifth and sixth analogue outputs (20–22) of first, second and third channels (3–5) of receiving seismic signals, respectively; first, second and third control inputs (23–25) of first, second and third channels 3–5 of receiving seismic signals, respectively. First seismic signal reception channel (3) includes second spring (26) mechanically connected to housing (12) and sealed housing (1). Each channel for receiving seismic signals includes an elastic second support (27), series-connected second capacitive displacement sensor (28), second demodulator amplifier (29), switch (30), second feedback unit (31) and second magnetoelectric transducer (32). Housing (12) is mechanically connected to the elastic second support (27), to the second capacitive displacement sensor (28) and to the second magnetoelectric converter (32). Second capacitive displacement sensor (28), resilient second support (27) and second magnetoelectric transducer (32) are mechanically connected to tight housing (1). Second capacitive displacement sensor (28) and second amplifier-demodulator (29) are connected to generator (2). First, second and third analogue outputs (6–8) are connected to first amplifiers-demodulators (17) of the first, second and third channels (3–5) of receiving seismic signals, respectively. Fourth, fifth and sixth analogue outputs (20–22) are connected to second amplifiers-demodulators (29) of the first, second and third channels (3–5) of receiving seismic signals, respectively. First, second and third calibration inputs (9–11) are connected to second magnetoelectric transducers (32) of first, second and third channels 3–5 of receiving seismic signals. First and second feedback units (18, 31) are made in the form of series-connected filter and amplifier. First, second and third control inputs (23–25) are connected to switches (30) of first, second and third channels (3–5) of receiving seismic signals, respectively. 
     EFFECT: technical result is high accuracy of measuring seismic vibrations. 
     1 cl, 1 dwg