SU555360A1 - Device for the excitation of seismic signals - Google Patents

Description

one

The invention relates to the field of geophysics and can be used in the development of devices for the excitation of seismic signals in marine seismic surveys when grouping explosive chambers.

A device is known for initiating seismic vibrations in water by exploding gaseous explosive mixtures in an explosive chamber with a radiating elastic diaphragm with L-shaped edges 1. The main disadvantage of this device is the impossibility of obtaining a series of pulses in one cycle of explosion of a gas mixture, which is necessary when working in accumulation mode of seismic effects, in order to increase the depth of research.

A device for initiating seismic vibrations in water by gaseous explosive mixtures is known, which contains a group of single explosive chambers and a supply and explosive gas explosive mixture line consisting of a detonation head of a gas main and distributing hoses 2. A disadvantage of the device is that single explosive chambers distributed over a certain area, so an areal source of seismic vibrations is obtained. This entails difficulties in using the source in the accumulation mode of seismic impacts.

It is also known a device for exciting a seismic signal comprising

Single cameras and the initiator, single cameras are located close to each other 3.

The main disadvantage of the prototype is the impossibility of using it to receive consecutive pulses with predetermined delays and, therefore, to fully achieve the advantages of the seismic effects accumulation mode.

The purpose of the invention is to increase the effectiveness of exploration by increasing the depth of exploration during the production of a series of pulses.

The goal is achieved by the fact that single blasting chambers are made in the form of

Claims (3)

tubes embedded in one another - shaped, and the explosion chamber thus formed is equipped with an elastic radiating diaphragm, on which one of the ends of the individual chambers is alternately fixed, and the opposite ends of the individual chambers are equipped with diffusers. FIG. 1 given the device, a general view; FIG. 2 is a section along A-A in FIG. 1. The device contains a U-shaped blast chamber 1, elastic radiating diaphragms 2 and 3, a firing pipe 4 with a spark plug 5 and an intake valve 6. Coaxially with a firing pipe 4, U-shaped pipes 7, 8 are inserted into the explosion chamber 1 and 9, the torps of which are alternately rigidly fixed on elastic radiating diaphragms 2 and 3, while the opposite ones are equipped with diffusers 10, 11 and 12 (for example, one of the ends of the pipe 7 is rigidly fixed on the elastic radiating diaphragm 2, and the other is provided with a diffuser 10 providing transition of a detonation wave into a tube 8. On to An explosion valve is installed in the explosion chamber 13. The device operates in the following manner: Through the inlet valve 6, the explosive chamber 1 supplies a combustible mixture, which displaces air (products of detonation) from the recovery chamber 1 to the atmosphere through the exhaust valve 13. After complete air removal ( detonation products) from the blast chamber 1, the exhaust valve 13 is closed. The pressure of the combustible mixture in the explosion chamber 1 rises to a predetermined value, and the inlet valve 6 is interrupted. The mixture ignites from the spark plug 5, and the detonation wave initiated in the ignition tube 4 propagates through the tube 7. Passing through the diffuser 10, the detonation wave acts on the radiating elastic diaphragm 3, which emits elastic vibrations into the water. At the same time, the detonation wave passes into the tube 8 and, having passed through it, acts on the radiating elastic diaphragm 2. The process repeats until the detonation wave passes through the diffuser 12 mounted on the tube 9. After this, the device is again ready for operation. The time intervals between pulses depend on the length of the explosion chamber and the detonation velocity of the explosive mixture. The length of the explosive amers and detonation velocity are constant, therefore, the intervals between pulses are also constant, which is very important when grouping sources of oscillations. It is known that the amplitude of the signal obtained in a series of explosions of charges weighing QJ J Qj QS 4 significantly exceeds the amplitude of the signal obtained in a charge explosion weighing Oz + Q, etc. Therefore, the use of the proposed device significantly increases the depth of research. The use of this device also provides a reduction in the radius of destruction of living organisms in the sea. Claims An apparatus for exciting seismic signals, comprising single blasting chambers and an initiator, characterized in that, in order to increase the effectiveness of exploration by increasing the depth of exploration during the production of a series of pulses, the single chambers are made in the form of tubes nested into one another and - shaped, fitted with elastic radiating diaphragm, on which one of the ends of the individual chambers is alternately rigidly fixed, and the opposite ends of the individual chambers are equipped with diffusers. Sources of information taken into account in the examination: 1. Author's certificate number 159301, M. Cl. G 01 V 1 / 1O, 1962. 2. Author's certificate No. 405092, M., 01 V 1/02, 1973. 3. The patent of Australia No. 260887, CL 85.2, 1965 (prototype).