SU554517A1 - Source of seismic signals in water - Google Patents

Description

one

The invention relates to the field of marine geophysics and can be used in the development of devices for exciting a seismic signal in water by explosions of gas mixtures in a vessel, measures with an elastic expansion shell.

A well-known source of seismic waves, non-slip, detonation of gases in a closed elastic chamber, which is hermetically sealed at the ends of the mechanical structure, including the tenon-conductor of the Trubono pipe; a pipeline with a control valve for the output of products d, etonation of the sea surface.

The disadvantage of the device is that these elements complicate the design and, in addition, when the detonation products are diverted to the day surface, part of the energy of the working agent is not productively consumed and the efficiency of the process decreases.

The complex configuration of the combustion chamber also reduces efficiency. devices, since during the expansion of detonation products, a part of the energy is consumed unproductively in the vortex flows of gases. The prototype of the proposed device is a source of seismic waves in water using a detonating gas mixture, containing a breech chamber in the form of an elastic shell with a supporting metal structure with a diameter of at least half the outer diameter of the chamber in its central part, and a device for feeding and igniting the mixture .

The disadvantage of the prototype is the difficulty of ensuring the stability of the emitted pulse, as well as the complexity of operation, since in marine conditions an additional stabilizing device is required to tow the device.

The aim of the invention is to provide

stability of the emitted signal and improved performance. This is achieved in that in the proposed device the metal structure is made in the form of a hollow cylinder, and the elastic shell is fixed at the ends of the cylinder on two annular elements, with the explosion chamber communicating with the environment in one permanently open channel, and in another ring element there is a communication channel of the explosion chamber with a device for feeding and igniting the gas mixture.

The drawing shows a diagram of the proposed source of seismic signals.

The seismic source is made

in the form of a cylindrical metal shell 1 and a cylindrical elastic shell 2, connected at the ends by two annular elements 3 and 4 so that between the shells 1 and 2 there is a cylindrical cavity in which the gas explosive mixture is accumulated and detonated.

The device works in the following way.

Through channel 5, a gas-explosive mixture is fed into the cavity between the cylinder 1 and shell 2. The output permanently open channel 6 simultaneously serves as an automatic regulator that prevents the chamber from overfilling with gas up to a pressure higher than hydrostatic, which ensures the stability of the emitted signal. The hot mixture is ignited in the prechamber 7, equipped with a flame arrester 8. The inner metal sheath I, which is the supporting structure for mounting elements of the device and the towing and digging system, simultaneously performs the role of the radiator stabilizer in motion and the role of the heat radiator that removes heat from explosive camera in the outside environment. The seismic signal is excited by two pulses lagging behind each other in time by an amount equal to the pulsation period. The first pressure pulse is excited by the detonation wave and the motion of elastic shell 2.

This causes the redistribution of explosion products, some of which are released into the environment through the outlet channel 6. The second pressure impulse is caused by the collapse of the gas bubble that has formed. Subsequent pulsations and a gas bubble are practically absent due to cooling and condensation of the explosion products. The use of a further pulse of the collapse allows to increase the amplitude of the seismic signal at the pulsation frequency.

In order to accelerate the process of condensation of explosion products, the device provides for a partial release of products into the environment, which is achieved by a special method of attaching the ends of an elastic cylinder, in which the surface of the un sheath 2 and the annular elements 1 and 3 and 4 represent

is a non-return valve, opening in the sides} ok) uzhayun1, its environment (for example, the end face. A part of the elastic shell. 2 is fixed to the flattened part of the supporting structure 3, 4 due to tension).

The proposed device was tested using a stoichiometric mixture of hydrogen and oxygen as a working agent, which made it possible to exclude pulsations of a GaAs bubble (as a detonation product in I

In this case, only water is in the form of superheated water vapor, which occurs during the first pulsation.

Explosive gases of a different composition may be used in the device.

Claims (1)

Invention Formula Source of seismic signals in water with using a gas mixture detonation, containing an explosive chamber in the form of an elastic shell C located in its central part with a supporting metal structure with a diameter not less than half of the diameter of the blasting chamber and the device for nodach.and zazh.igany mix, characterized in that, in order to ensure the stability of the emitted signal and improve performance, the metal structure is made in the form of a hollow cylinder, and the elastic shell is fixed on the ends of the cylinder: on two annular elements, wherein the explosion chamber communicates with the environment in one permanently open channel located in one ring element, and in the other ring element is connected a connection of the explosion chamber with the device for feeding and igniting the gas mixture. JU