SU1081589A1 - Multi-channel seismic prospecting device - Google Patents

Abstract

SEISMIC EXPLORATION MULTI-CHANNEL DEVICE, containing telemetry cable connected by connectors with floor points, in whose hard cases there are electronic units, characterized in that, in order to simplify the equipment, the rigid case is made in the form of a sleeve enclosed in an elastic detachable casing with a sealed cover in the place of the connector, fastened together by a clamping device, into the internal cavity of the housing, the telemetry cable located in the flexible holders fixed on a rigid case, the contact connectors being installed inside the cavity of the elastic split casing, which is provided with position fixers relative to the telemetry cable.

Description

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The invention relates to seismic exploration and can be used and multi-channel seismic complexes.

A known piezoelectric hose floating streamer for marine seismic surveys, comprising seismic receivers, matching transformers and auxiliary devices embedded in the streamer. The spit consists of 12-24 sections of 100 m each weighing 230 kg. The spit contains as many wire pairs as channels are used, the spit being the longest is 1200 m. For winding the spit a device is used which is a 1.2 m diameter drum equipped with an electric drive. The presence of devices built into the braid does not prevent the winding of the braid onto the drum 1.

A disadvantage of the known device is that it does not use a telemetry system for transmitting information, but uses a large number of long wires, which causes an unnecessarily large consumption of scarce materials and decreases the reliability of the device.

A multichannel seismic signal recording system is known, in which signals from seismic receivers are transmitted to a central recording point via a single pair of wires. The system includes a large number of floor points connected in parallel to one pair of wires. Seismic receivers or their groups are connected to each floor point. The outdoor units contain electronics units, connectors for connecting to the telemetry cable, seismic receivers and power sources. At the floor point, the signals from the geophone are summed with white noise. The sum signal is sampled and, upon command from the central point, is transmitted to the seismic survey station for recording 2.

The closest in technical essence to the present invention is a seismic multichannel device comprising a telemetry cable connected by connectors to floor points, in whose hard cases electronic units are installed.

Floor point serves one channel. Information transfer, diagnostic verification of the item and its power supply are carried out via a six-core cable. The item contains a series-connected amplifier with filters, an analog-code converter, a telemetry device and a switched diagnostic unit. The information data is transferred from point to point, where it is regenerated, until it arrives at the seismic station for recording. The device can operate in a 16-bit and sign information conversion mode. The weight of the floor point is 4 kg 3.

A disadvantage of the known devices is that their use requires placing on the ground a multitude of bulky floor points and connecting wires, since one floor point serves only one channel. Due to the use of long connecting wires, the devices are sensitive to external interference.

The aim of the invention is to simplify the apparatus.

The goal is achieved by the fact that in a seismic multi-channel device containing a telemetry cable connected by contact connectors with floor points, in rigid cases of which electronic units are installed, the rigid case is made in the form of a sleeve enclosed in an elastic detachable housing with a sealed cover in place of the connector fastened between each clamping device, telemetry cable located in flexible holders fixed to a rigid building is passed into the internal cavity of the housing lo, wherein the connectors are mounted within the cavity of the elastic split shroud is provided which locks the position relative to the telemetry cable.

FIG. 1 is a floor point structure diagram; in fig. 2 - floor point, section; in fig. 3 is a view A of FIG. 2

The device includes a telemetry cable 1, a floor point 2, a two-wire sealed branch 3 to a seismic receiver, a seismic receiver 4, an amplifier 5 of the ground point; block 6 with frequency filters, including low-pass filter 7, high-pass filter 8, notch filter 9, mixer 10, automatically controlled by the input signal white noise generator 11, analogue converter 12, telemetric information transfer unit 13, switched diagnostic unit 14, mounting boards 15 floor point, rigid sleeve 16, elastic split casing 17, flexible holders 18 and

19cable, flexible sealed ceilings

20 and 21, the elongated part 22 of the flexible overlap, a longitudinal cavity 23 located along the casing, screws 24 fastening between two metal plates of the pressing device, the upper metal plate 25 and the lower metal plate 26 of the pressing device, clamps 27 and 28 of the casing of the floor point with respect to telemetry cable, contact connectors 29 34 telemetry cable, spring-loaded connectors 35-40, installed inside the elastic detachable casing of the floor point. Seismic multichannel device operates as follows. After unwinding the telemetric dsabel 1 with floor points 2 fixed to it, tapes 3 connect seismic receivers or groups 5 of seismic receivers 4. The signal from the seismic receiver goes to the amplifier 5 of the floor point, then passes the filter block b including the low pass filter 7, a high-pass filter 8, a notch Q filter 9, and a mixer 10. The device can operate in a low-resolution mode, for example, a sign or full-size one, for example, a 16-bit, information conversion. In the first case, a white noise generator 11 is automatically controlled by the input signal. To restore the true ratios of the amplitudes of the analyzed signals, the signal before encoding must be shifted with white noise exceeding the useful signal by at least 1.1-1.5 times. In the generator 11, the signal from the filter 9 automatically sets the required white noise level that goes to the first input of the mixer 10. To the second input of the mixer 10, the amplified and filtered signal from the output of the filter 9 is fed. Thus, in the mixer, the required level The ratio is shifted by the signal with white noise. From the output of the mixer, the signal with white noise enters the low-level, for example, sign, analog-code converter 12, then to block 13 and the cable to the seismic station for data recording. The switched diagnostics unit 14 allows to check the performance of the seismic receiver and the floor point. The blocks 35 listed above are mounted on the mounting plates 15 located inside the rigid sleeve 16. The sleeve is placed in an elastic detachable casing 17, which can be made of high-strength and resistant to the use of material-40, such as synthetic rubber or nylon. Inside the case there are flexible cable holders 18 and 19 for holding the case of the floor point on the cable. These holders are fixed on the hard case of the floor45 item. To protect the floor from moisture and dust penetration, the split casing contains flexible overlaps 20 and 21, with one of the overlaps having an elongated part 22. Inside the casing there is a cavity 23, in the lower part of which a telemetry cable is placed, and the upper part of this cavity allows the flexible cable holders and remove or put on the floor point on the cable, Hermetic overlap in place of the connector are fastened together with screws 24 of the clamping device, which includes the top 25 and bottom 26 metal plates. Clamps 27 and 28 are installed in the end portions of the casing, which fix the position of the casing of the floor point relative to the telemetry cable. These clips prevent the housing from moving along the cable. For the galvanic connection of the electronics of the floor unit with the telemetry cable, contact connectors 29-34 are installed on it. The same number of spring-loaded pin connectors 315-40 is installed inside the elastic split casing. The power supply floor point gets on the conductors of the cable. At any time, the floor item can be removed from its place for repair or replacement. To do this, it is necessary to unscrew the screws 24, remove the upper metallic plate 25 of the clamping device, bend the elongated part 22 of the flexible overlap and move the flexible holders 18 and 19 of the cable apart. After the € нап of the floor item, pull out on the backup cable so that the protrusions and depressions of clamps 27 and 28 are aligned. For ease of use, the cable can be made split or sectioned, for example, 24-28 channels per section. The positive effect of using the proposed device is due to the saving of scarce wires and the reduction of labor costs for arranging a lot of bulky ground points on the ground. Cost savings, depending on the duration of the field season, can be 15-20 / o of the total field costs, with the exception of the cost of exciting seismic waves.

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Claims (1)

A SEISMIC EXPLORATION MULTI-CHANNEL DEVICE containing a telemetric cable connected by contact connectors to floor points, in whose rigid cases electronics units are installed, characterized in that, in order to simplify the equipment, the rigid case is made in the form of a sleeve enclosed in an elastic detachable casing with a tight seal in the place of the connector, fastened together by a clamping device, a telemetric cable is located in the flexible holders fixed to the gesture into the internal cavity to the burn com body, with contact connectors mounted inside the cavity of an elastic detachable casing, which is equipped with position locks relative to the telemetry cable. <g Figure 1 SU .... 1081589