Abstract: The invention includes a method and apparatus for detecting geophysical phenomena by the use of a synthetic pulse radar. A radar transmitter generates a plurality of component signals of different frequencies which approximate at least a portion of the Fourier transform of a radar short pulse. These component signals are transmitted simultaneously for modulation by the geophysical phenomena, and the modulated component signals are substantially simultaneously received in a receiver. The receiver divides the component signals, and as to each determines representative parameters. The invention also includes a heterodyne receiver which operates with a fixed IF frequency and incorporates a single frequency quadrature system.

Abstract: A method of fracturing a deep borehole to form a vertical fracture, and of determining the azimuth of the resulting fracture, comprising pumping a pressurized fracture fluid into said well through a pipe from the surface, to provide a bottom hole pressure P which is less than the normal fracturing press (NFP), and generating a series of sharp pressure pulses (SPP) of selected magnitude, such that when added to the pressure P, provide pressure peaks greater than the NFP. By providing arrays of seismic sensors at the surface and determining the direction of propagation of the seismic waves generated by the SPP, the azimuth of the fracture can be determined.

Abstract: The present invention relates to a method and apparatus for selectively providing an alarm-generating digital code so as to alert an operator that the next-in-time positions of a source-detector array are the last approved locations before the recording truck location must be changed, i.e., "rolled forward" a predetermined distance along the line of survey and array parameters renormalized.

Abstract: The present invention relates to testing--at a second recording truck--a positional reference code (generated by a first recording truck); the reference code (associated with next-in-time positions of a source-detector array operatively connected to the second truck) is interrogated using a microcomputer system of a ground positional controller housed in the second truck. Result: coordination of operations (between trucks) is assured.

Abstract: In the process of recovering minerals, such as hydrocarbons from shallow tar sands, and the like, one method is to create a shallow horizontal fracture within the tar sand. The size and shape of the perimeter is determined, and one or more secondary boreholes are drilled to the formation inside of the perimeter of the fracture. Pressurized air is injected into the fracture and the hydrocarbons are ignited. After a selected period of burning is carried out, the radius to the burn front, surrounding the recovery area, from which the hydrocarbons have been removed, is determined by placing a source of seismic waves at a selected point over the fracture, and a long array of seismic sensors colinear with the source.The source is energized for different conditions of pressurization in the formation and fracture. The reflected seismic waves are converted to electrical signals, which are compared for all sensors.

Abstract: A seismic method for mapping horizontal fractures in the earth resulting from the application of fluid pressure, at a selected point, at a selected depth, in the earth, comprising the steps of creating a seismic wave in the earth over the expected position of the fracture, and detecting the seismic waves reflected upwardly at a reflecting interface, at or near the fracture, at each of a plurality of seismic sensors, in at least one radial array. The received signals are recorded for each of two conditions: a first case, when the fracture is pressurized, and filled with fluid, and the roof of the fracture is separated from the base of the fracture; and a second case when the fracture is depressurized, and the roof of the fracture rests on the base. Some sensors will show a different character of reflection signal in the two cases. For these sensors the points of reflection are within the outer perimeter of the fracture.

Abstract: This invention relates to pulse radar detection of targets in extended media, including natural phenomena such as oil, coal and ore deposits within the earth. In particular, this invention relates to a pulse radar system employing a synthetic pulse formed from a Fourier spectrum of frequencies generated and detected by a digitally controlled transmitter and receiver circuits.

Abstract: An improved seismic prospecting system comprising the use of a closely spaced sequence of source initiations at essentially the same location to provide shorter objective-level wavelets than are obtainable with a single pulse. In a preferred form, three dynamite charges are detonated in the same or three closely spaced shot holes to generate a downward traveling wavelet having increased high frequency content and reduced content at a peak frequency determined by initial testing.