Seismic signal generator

Claim 2

A seismic sound wave generator system for creating sound waves forming a seismic signal which comprises a casing including a gas differential pressure system defining a main chamber and a control chamber each adapted to contain gas under pressure, the control chamber being substantially smaller in volume than the main chamber, a pressure equalizing orifice connecting the control chamber and the main chamber, at least one impulse producing exhaust portion in the main chamber, the gas differential pressure system including gas pressure responsive slidable opening and closing means for opening the impulse producing exhaust port to discharge at least one-fourth of the high-pressure gas in the main chamber within 10 milliseconds and for closing the impulse producing exhaust port, the slidable opening and closing means having opening and closing surfaces at opposite ends thereof exposed to gas pressure respectively in the main and in the control chambers, the closing surface of the opening and closing means in closed position having an effective area subject to gas pressure greater than the effective area subject to gas pressure of the opening surface, the opening and closing means being responsive to a gas pressure differential across the main and control chambers to close and remain closed at a control chamber pressure at which the force applied on the closing surface of the opening and closing means from the control chamber is equal to or greater than that applied to the opening surface of the opening and closing means from the main chamber, gas inlet means connected to at least one of the main chamber and the control chamber, secondary exhaust means in the control chamber, the gas inlet means being adapted to be connected to a high-pressure gas source, and externally controlled valve means for rapidly reducing the control chamber pressure to a predetermined pressure at which the force applied on the closing surface of the opening and closing means of the differential pressure system from the control chamber is less than that applied on the opening surface of the opening and closing means from the main chamber such that the opening and closing means rapidly opens and automatically closes.

Claim 3

The system of claim 1 wherein the valve means is a solenoid valve.

Claim 4

The system of claim 1 wherein the opening and closing means starts to exhaust the high-pressure gas in the main chamber out of the lateral exhaust ports within + or - 2 milliseconds of the desired release time.

Claim 5

The system of claim 3 wherein the opening and closing means discharges at least one-half of the high-pressure gas in the main chamber within 3 milliseconds.

Claim 6

The system of claim 1 wherein the opening and closing means include means for exhausting the high-pressure gas repeatedly using an interval time period of less than about 10 seconds.

Claim 7

The system of claim 5 wherein the high-pressure gas can be exhausted repeatedly using an interval time period of less than about 7 seconds.

Claim 8

The system of claim 5 wherein the opening and closing means includes means for varying at will the exhaust interval time period from an external point.

Claim 9

The system of cLaim 1 wherein the externally controlled valve means includes means for exhasuting the high-pressure gas from the main chamber at a pressure of from about 2,000 to about 20, 000 p.s.i.a. and includes means for sealing off the main chamber at a pressure of from about 500 to about 6,000 p.s.i.a.

Claim 10

The system of claim 1 wherein the externally controlled valve means includes means for exhausting the high-pressure gas from the main chamber at a pressure of from about 5,000 to about 12, 000 p.s.i.a. and includes means for sealing off the main chamber at a pressure of from about 1,500 to about 5,000 p.s.i.a.

Claim 11

The system of claim 1 including means for varying the characteristics of the sound waves.

Claim 12

The system of claim 1 including means for concentrating the sound waves in a directional manner.

Claim 13

The system of claim 1 wherein the main chamber has a volume of from about 10 to about 200 cubic inches.

Claim 14

The system of claim 1 wherein the means for supplying the high-pressure gas to the generator comprises a boat, compressor means mounted on the boat, and high-pressure gas conduit means interconnecting the compressor means with the generator, said generator being towed underwater by the boat.

Claim 15

The system of claim 13 including a plurality of generators attached to the compressor means and means for firing the generators sequentially, the generators being towed underwater by the boat.

Claim 16

The system of claim 1 wherein the means for supplying the high-pressure gas to the generator comprises compressor means and high-pressure gas conduit means interconnecting the compressor means with the generator, the generator being placed underground.

Claim 17

The system of claim 15 including a plurality of generators attached to the compressor means, and means for firing the generators sequentially, the generators being placed underground.

Claim 18

A system comprising the generator of claim 1 in combination with a quick release valve mechanism for rapidly discharging the high-pressure gas in the control chamber at a point adjacent the secondary exhaust means in the control chamber.

Claim 19

The system of claim 1 wherein the opening and closing means includes a valve element slidably mounted in the main chamber for opening and closing the exhaust ports and having a first surface exposed to the high-pressure gas in the main chamber and a second surface exposed to the high-pressure gas in the control chamber, the area of the first surface being less than the area of the second surface when the element is in a position closing the exhausts ports and no greater than the area of the second surface when the element is in a position opening the exhaust ports, the differential pressure applied to said first and second surfaces moving the valve element to open and close the exhaust ports.

Claim 20

The system of claim 18 further including a valve seat for the valve element, the valve seat being slidably mounted in the main chamber adjacent the valve element and having a third surface exposed to the high-pressure gas in the main chamber, he combined area of the third and first surfaces being no greater than the area of the second surface when the valve element is in a position closing the exhaust ports.

Claim 21

The system of claim 19 wherein the valve seat has a first lip and the wall of the main chamber has a second lip contacting the first lip to limit movement of the valve seat as the valve seat moves with the valve element towards the position in which the exhaust ports are open.

Claim 22

The system of claim 18 wherein the gas inlet means for the main chamber and the control chamber is the same and includes a single inlet to the generator and check valve means in the gas inlet means for preventing flow out of the main chamber.

Claim 23

The system of claim 18 wherein the gas inlet means for the main chamber and the control chamber includes separate inlet passages for each of the two chambers.

Claim 24

The system of claim 18 wherein theRe is one impulse producing exhaust port and including means for concentrating the sound waves in the direction outwardly of the exhaust port formed by said impulse producing port and said valve element, said valve element being an annular element slidably mounted to seat in one direction around the exhaust port to close the exhaust port and to seat in another direction in the control chamber, said control chamber being an annular chamber formed around a plug element, the main chamber surrounding the valve element.

Claim 25

The system of claim 23 wherein the end of the plug element extending toward the exhaust port is tapered.

Claim 26

The system of claim 23 including an annular valve seat for the annular valve element, the valve seat being slidably mounted in the main chamber adjacent the valve element and having a third surface exposed to the high-pressure gas in the main chamber, the combined area of the third and first surfaces being no greater than the area of the second surface when the valve element is in a position closing the exhaust ports, a first lip on the valve seat, and a second lip on the wall of the main chamber at the exhaust port contacting the first lip upon movement of the valve seat to limit movement of the valve seat as it moves with the valve element towards the position in which the exhaust ports are open.

Claim 27

An assembly for creating pneumatic impulses which comprises a casing including a differential pressure system defining a main chamber and control chamber adapted to contain a high-pressure gas, impulse producing exhaust ports and gas inlet means in the main chamber, the differential pressure system including an element for opening and closing the impulse producing exhaust ports responsive to the pressure differential across the main and control chambers, gas inlet and secondary exhaust means in the control chamber, the gas inlet means for the control chamber being adapted to be connected to a high-pressure gas source, the high pressure portion of the differential pressure system during filling of the assembly with high-pressure gas including the control chamber, externally controlled valve means for rapidly reducing control chamber pressure to a pressure at which the force applied on the movable element of the differential pressure system from the control chamber is less than that applied on the movable element from the main chamber, and a quick release valve mechanism for rapidly discharging the high-pressure gas in the control chamber at a point adjacent the secondary exhaust means in the control chamber which comprises (a) a casing (1) having a chamber therein with an inlet end and an outlet end, and provided with at least one exhaust port, and (2) having an inlet port and an outlet port communicating respectively with the inlet end and the outlet end for the transportation of high pressure gas; (b) a release piston for opening or closing the exhaust port (1) slidable in the chamber for controlling the exhaust port, (2) which has a passage bore, for passage therethrough of high-pressure gas from the inlet port to the outlet port of the casing chamber, which has a narrowed portion on the inlet side and which penetrates to a position in fixed relationship to the end of the release piston towards the inlet port and which branches at that point in a direction whereby the passage bore penetrates the axial wall of the release piston, (3) which has a narrowed portion on the end towards the inlet port which allows communication between the inlet port and the passage bore when the release piston is in a position exposing the inlet port, and (4) which in the exhaust port opening position seats against the inlet end of the chamber in a manner which seals the inlet port and exposes the exhaust port and which in the fill position seats against the outlet end of the chamber in a manner which allows communication between the inlet port and the outlet port; (c) a ball check in the passage bore which in the normal position seats agAinst the narrowed portion of the passage bore; and (d) a spring (1) positioned in the passage bore with one end engaging the ball check and the other end engaging the outlet end of the chamber, and (2) which is incapable of seating the ball check against incoming pressure and sustaining the ball check in he normal position and holding the release piston in the exhaust port opening position until the incoming pressure is reduced, whereupon the spring will seat the ball check and cause the release piston to shift into the exhaust port opening position.

Claim 28

An assembly for creating pneumatic impulses which comprises a casing including a differential pressure system defining a main chamber and control chamber adapted to contain a high-pressure gas, impulse producing exhaust ports and gas inlet means in the main chamber, the differential pressure system including an element for opening and closing the impulse producing exhaust ports responsive to the pressure differential across the main and control chambers, gas inlet and secondary exhaust means in the control chamber, the gas inlet means for the control chamber being adapted to be connected to a high-pressure gas source, the high pressure portion of the differential pressure system during filling of the assembly with high-pressure gas including the control chamber, externally controlled valve means for rapidly reducing control chamber pressure to a pressure at which the force applied on the movable element of the differential pressure system from the control chamber is less than that applied on the movable element from the main chamber, and a quick release valve mechanism for rapidly discharging the high-pressure gas in the control chamber at a point adjacent the secondary exhaust means in the control chamber which comprises (a) a casing (1) having a chamber therein with an inlet end and an outlet end, and provided with at least one exhaust port, and (2) having an inlet port and an outlet port communicating respectively with the inlet end and the outlet end for the transportation of high pressure gas; (b) a release piston for opening or closing the exhaust port (1) slidable in the chamber for controlling the exhaust port, (2) which has a passage bore, for passage therethrough of high-pressure gas from the inlet port to the outlet port of the casing chamber, which has a narrowed portion on the inlet side and which penetrates to a position in fixed relationship to the end of the release piston towards the inlet port and which branches at that point in a direction whereby the passage bore penetrates the axial wall of the release piston, (3) which has a narrowed portion on the end towards the inlet port which allows communication between the inlet port and the passage bore when the release piston is in a position exposing the inlet port, and (4) which in the exhaust port opening position seats against the inlet end of the chamber in a manner which seals the inlet port and exposes the exhaust port and which in the fill position seats against the outlet end of the chamber in a manner which allows communication between the inlet port and the outlet port; (c) a ball check in the passage bore which in the normal position seats agAinst the narrowed portion of the passage bore; and (d) a spring (1) positioned in the passage bore with one end engaging the ball check and the other end engaging the outlet end of the chamber, and (2) which is incapable of seating the ball check against incoming pressure and sustaining the ball check in he normal position and holding the release piston in the exhaust port opening position until the incoming pressure is reduced, whereupon the spring will seat the ball check and cause the release piston to shift into the exhaust port opening position.

Claim 29

The system of claim 26 wherein the quick release valve mechanism is directly attached to the secondary exhaust means in the control chamber at the interface formed by the outer face of the casing of the assembly.

Claim 30

The system of claim 27 wherein the valve means is a solenoid valve.

Claim 31

The system of claim 28 wherein the solenoid valve is located as much as about 50 feet from the assembly for creating pneumatic impulses.

Claim 32

The system of claim 26 wherein the quick release valve mechanism is attached to the secondary exhaust means via a high-pressure gas conduit which is less than 25 feet in length.

Claim 33

The system of claim 30 wherein the valve means is a solenoid valve.

Claim 34

The system of claim 26 wherein the means for supplying the high-pressure gas to the assembly comprises a boat, compressor means mounted on the boat, and high-pressure gas conduit means interconnecting the compressor means with the assembly, said assembly being towed underwater by the boat.

Claim 35

The system of claim 32 including a plurality of assemblies attached to the compressor means, and means for firing the assemblies sequentially, the assemblies being towed underwater by the boat.

Claim 36

The system of claim 26 wherein the means for supplying the high-pressure gas to the assembly comprises compressor means, and high-pressure gas conduit means interconnecting the compressor means with the assembly, the assembly being placed underground.

Claim 37

The system of claim 34 including a plurality of assemblies attached to the compressor means, and means for firing the assemblies sequentially, the assemblies being placed underground.

Claim 42

A seismic sound wave generator system for creating sound waves forming a seismic signal which comprises a casing including a gas differential pressure system defining a main chamber and a control chamber each adapted to contain gas under pressure, the control chamber being substantially smaller in volume than the main chamber, a pressure equalizing orifice connecting the control chamber and the main chamber, at least one impulse producing exhaust port in the main chamber, the gas differential pressure system including gas pressure responsive slidable opening and closing means for opening the impulse producing exhaust port to discharge at least one-fourth of the high-pressure gas in the main chamber within 10 milliseconds and for closing the impulse producing exhaust port, the slidable opening and closing means having opening and closing surfaces at opposite ends thereof exposed to gas pressure respectively in the main and in the control chambers, the opening surface of the slidable opening and closing means being seated in closed position such that the effective area of the opening surface in the main chamber exposed to gas pressure tending to open the opening and closing means is less than the effective area of the closing surface in the control chamber exposed to gas pressure tending to close the opening and closing means, the opening and closing means being responsive to a gas pressure differential across the main and control chambers to close and remain closed at a control chamber pressure at which the force applied on the closing surface of the opening and closing means from the control chamber is equal to or greater than that applied to the opening surface of the opening and closing means from the main chamber, gas inlet means connected to the main chamber, secondary exhaust means in the control chamber, the gas inlet means being adapted to be connected to a high-pressure gas source, and externally controlled valve means for rapidly reducing the control chamber pressure to a predetermined pressure at which the force applied on the closing surface of the opening and closing means of the differential pressure system from the control chamber is less than that applied on the opening surface of tHe opening and closing means from the main chamber such that the opening and closing means rapidly opens and automatically closes.

Claim 43

A seismic sound wave generator system for creating sound waves forming a seismic signal which comprises a casing including a gas differential pressure system defining a main chamber and a control chamber each adapted to contain gas under pressure, the control chamber being substantially smaller in volume than the main chamber, a pressure equalizing orifice connecting the control chamber and the main chamber, at least one impulse producing exhaust port in the main chamber, the gas differential pressure system including gas pressure responsive slidable opening and closing means for opening the impulse producing exhaust port to discharge at least one-fourth of the high-pressure gas in the main chamber within 10 milliseconds and for closing the impulse producing exhaust port, the slidable opening and closing means having opening and closing surfaces at opposite ends thereof exposed to gas pressure respectively in the main and in the control chambers, the opening surface of the slidable opening and closing means being seated in closed position such that the effective area of the opening surface in the main chamber exposed to gas pressure tending to open the opening and closing means is less than the effective area of the closing surface in the control chamber exposed to gas pressure tending to close the opening and closing means, the opening and closing means being responsive to a gas pressure differential across the main and control chambers to close and remain closed at a control chamber pressure at which the force applied on the closing surface of the opening and closing means from the control chamber is equal to or greater than that applied to the opening surface of the opening and closing means from the main chamber, gas inlet means connected to the main chamber, secondary exhaust means in the control chamber, the gas inlet means being adapted to be connected to a high-pressure gas source, and externally controlled valve means for rapidly reducing the control chamber pressure to a predetermined pressure at which the force applied on the closing surface of the opening and closing means of the differential pressure system from the control chamber is less than that applied on the opening surface of tHe opening and closing means from the main chamber such that the opening and closing means rapidly opens and automatically closes.