Apparatus and method for use in marine seismic surveying

A seismic source system for use in marine seismic surveying, comprising:

• (a) a seismic transmitter array having a front end and a plurality of transmitters placed in a spaced relation to each other, each transmitter adapted to receive high pressure air and in response thereto producing a pressure pulse in a body of water;
• (b) a floatation device having:
• (i) a nose member;
• (ii) a plurality of air tight chambers connected to each other to form a string, one end chamber in the string terminating at the nose member and the other adapted to receive pressurized air;
• and
• (iii) a separate one-way fluid check valve placed between each pair of adjacent chambers in the string in a manner which enables the air from the chamber receiving the air to pass to the remaining chambers;
• and
• (c) The front end of the seismic transmitter array connected to the nose member, said array also connected to the floatation device at a plurality of points in a manner so that when said seismic source array is towed from a tow point on the nose in a body of water, the nose member remains forward of the front end of the seismic transmitter array and that the floatation device maintains the seismic transmitter array at a constant depth and in a horizontal straight-line position below the water surface.

A seismic source system comprising:

• (a) an air gun subarray having:
• (i) a frame having a front and rear ends;
• (ii) a plurality of air guns suspended from the frame and placed in a spaced relation to each other, each air gun adapted to produce shock pulses in response to high pressure air;
• and
• (iii) means for supplying high pressure air to said each gun;
• (b) a floatation device adapted to provide buoyant force to the air gun subarray having:
• (i) a nose member having a tow point thereon;
• (ii) a plurality of air tight chambers connected to form a longitudinal member, the chamber at one end of the longitudinal member connected to the nose member and the chamber at the other end adapted to continuously receive air under pressure;
• and
• (iii) a separate one-way check valve connected between each pair of adjacent chambers in a manner that enables the air to pass from the chamber receiving the pressurized air to the remaining chambers;
• and
• (c) the air gun subarray pivotly connected to the floatation device at a plurality of points, and said nose member connected to the front end of the air gun subarray in a manner that will maintain the nose member in front of the air gun subarray when the seismic source system is towed from the tow point in a body of water and also will maintain the air gun subarray at a constant depth below the water surface and in a horizontal straight line position.