摘要 |
A method and system are provided for well velocity shooting and vertical seismic profiling utilizing mobile seismic land sources for transmitting powerful seismic energy impulses into the earth. A plurality of nesting pairs of tanks are transported on a single vehicle to a well site where the tanks are unloaded and arranged in a suitable array, for example, in a linear array or uniformly spaced around the mouth of the well. The tanks each have a displaceable end portion serving as a diaphragm placed in contact with the ground near the well. Then the tanks are filled with a noncompressible liquid. The total effective mass of the liquid may be increased by adding density-increasing materials thereto. Air guns are suspended in the tanks submerged in the liquid therein. The air guns are fired in a predetermined manner, abruptly releasing pressurized gas into the liquid contained in the tanks for providing powerful seismic impulses which are transmitted into the ground by the displaceable diaphragms. Geophone equipment lowered into the well receives the resultant waves which have passed through the geological structures near the well, and the signals from the geophone equipment may be recorded and/or processed at ground level. Advantageously, a mobile system is provided in which a single vehicle can provide an array of four seismic sources instead of requiring two or four vehicles to provide a like number of sources.
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