SU1529157A1 - Apparatus for receiving seismic signals - Google Patents

Abstract

The invention relates to geophysical instrumentation and can be used to create borehole multicomponent multipoint probes for performing seismic acoustic studies using the polarization method. The aim of the invention is to expand the operational capabilities of the seismic receiver by ensuring its operability at different tilt angles relative to the vertical while simplifying the electronic unit. Connecting to the winding of the moving coil an amplitude detector and generator with an operating frequency equal to the resonant frequency of the filter, eliminates rubbing of the moving coil in the working gap of the geophone and control the position of its zero point. 3 il.

Description

The invention relates to geophysical instrumentation and can be used to create borehole multicomponent multipoint probes for performing seismic acoustic studies using the polarization method.

The aim of the invention is to expand the operational capabilities of the seismic receiver by ensuring its operability at different tilt angles relative to the vertical while simplifying the electronic unit.

Figure 1 shows the geophone, a longitudinal section and a block diagram of the proposed device; Fig. 2 shows an electronic unit, an example of implementation; fig.Z - diagrams of the proposed device.

A device for receiving seismic signals (FIG. 1) comprises a seismic receiver 1 comprising a housing 2 with a fixed magnet 3 fixed therein and a moving coil 4 with a winding 5 suspended on a spring 6 in a magnetic gap 7 between the housing 2 and a permanent magnet 3. In the electronic unit, including the generator 8, the amplitude detector 9 and the filter 10, the output of the generator 8 is connected to the winding 5 of the moving coil 4 of the geophone connected to the input of the linear detector 9, the output of which is connected through the filter 10 to the output 11 of the recorder. In this case, the resonant frequency of the filter is chosen equal to the operating frequency of the generator.

In the electronic unit shown in figure 2, the generator 8 is made on

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the VTl transistor, the amplitude detector 9 - on the operational amplifier DA1.1, and the filter 10 - on the operational amplifier DA1.2.

The device operation diagrams (Fig. 3) show: a signal at the output of a reference seismic receiver, identical to a satellite receiver 1 used in the device, placed vertically near it (a); the signal at the output of the generator 8 (b); the signal at the input of the amplitude detector 9 when installing the geophone 1 at an angle to the vertical, greater than permissible according to the technical conditions (c); signal at the input of the filter 10 (g); Signal on Vygcode 11 registrar (d).

As a seismic receiver, any electrodynamic seismic receiver can be used, for example, SV-10 SV-20, etc.

The generator can be made on the KT208 transistor, and the linear detector and the filter can be made on the operational amplifier KR1401UD1. The device uses resistors of the MLT-0.125 type, and the capacitors are K73-P, K53-1.

A device for receiving seismic signals operates as follows.

With an arbitrary position of the seismic receiver 1 relative to the vertical (such a case occurs when carrying out vertical seismic profiling in inclined wells) after switching on the device, generator 8 generates a sinusoidal signal arriving at the winding 5 of the moving coil 4, prompting the latter to oscillate in the magnetic gap 7. Amplitude- Yes, this signal is selected for each type of seismic receiver such that during oscillation the movable coil 4 at an arbitrary position of the instrument axis is in the position which e held in the vertical axis of the arrangement. At the same time at the entrance

the amplitude detector 9, the received seismic signal is summed with the generator signal 8. The resulting sum signal is detected by the amplitude detector 9. The spectral components of the detected signal, whose frequency is higher than the maximum frequency of the seismic signal, are filtered out by the filter 10.

The proposed device for receiving seismic signals eliminates seismic receiver failures when its axis deviates from the vertical by eliminating rubbing the coil B in the gap, and its periodic return to the zero point ensures that the seismic detector parameters are identical at different angles of inclination, which makes it possible to use vertical light detectors for multi-component acquisition of seismic signals in inclined wells.

Claims (1)

Invention Formula A device for receiving seismic signals, comprising a seismic receiver with a magnetoelectric transducer, a recorder and an electronic unit with a generator and a filter, characterized in that, in order to expand the operational capabilities of the seismic receiver by ensuring its operability at different angles of inclination relative to the vertical while simplifying the electronic unit, it is equipped an amplitude detector, with the generator output connected to the winding of a moving transducer coil - seismic receiver, connected to the input of the linear detector, the output of which is connected through a filter to the recorder. fig 2 Lllll A / lA / U figs