Abstract: The present disclosure relates to detecting subterranean formations using electromagnetic depth sounding. A method for detecting formation properties may comprise of disposing a transmitter at a surface, disposing a receiver at the surface, coupling a high frequency wave to a low frequency wave to form an electromagnetic pulse, transmitting the electromagnetic pulse into a formation from the transmitter, receiving a reflected electromagnetic wave from the formation with the receiver, and determining the depth and nature of the formation from the surface. A formation measuring system may comprise a transmitter, wherein the transmitter is configured to couple a high frequency wave to a low frequency wave to form an electromagnetic pulse. The formation measuring system may further comprise at least one receiver, a data acquisition system, and an analysis unit.

Abstract: The present disclosure relates to detecting subterranean formations using electromagnetic depth sounding. A method for detecting formation properties may comprise of disposing a transmitter at a surface, disposing a receiver at the surface, coupling a high frequency wave to a low frequency wave to form an electromagnetic pulse, transmitting the electromagnetic pulse into a formation from the transmitter, receiving a reflected electromagnetic wave from the formation with the receiver, and determining the depth and nature of the formation from the surface. A formation measuring system may comprise a transmitter, wherein the transmitter is configured to couple a high frequency wave to a low frequency wave to form an electromagnetic pulse. The formation measuring system may further comprise at least one receiver, a data acquisition system, and an analysis unit.

Abstract: Transponders in or with a shallow water seismic cable emit acoustic signals for acoustic ranging on command from a transceiver aboard a seismic exploration vessel. The acoustic ranging data together with navigational data cna be used to identify cable location. The transponders are activated by individual identifying digital codes. Each such digital code is a data word of suitable length composed of a distinctive frequency sent in bursts for a specific time for successive pairs of bits, or di-bits, in the data word. The time spacing between sending the frequency bursts is also used to carry other di-bits of the data word.

Abstract: A method is disclosed where acoustic pulses are used to calculate the velocity of the medium. The inventive aspect of the invention is that the acoustic velocity may be calculated without initially knowing the separation distance between the source and the distant receivers. The method utilizes established geometrical relationships which may be solved to produce the velocity. The velocity is often used to calculate the separation distances between the desired points.

Abstract: A latching mechanism used to couple external devices to marine seismic streamer cables is disclosed. The latching device universally couples to collars predominantly used in the seismic industry. A mounting bracket or shank is provided which is coupled to the external device. The shank has a lug or finger fixed therein which extends from a mounting surface. Adjacent the lug is a latching device which is comprised of a cylinder having a cam defined at the upper end. The cylinder is recessed within the shank so that the cam and the lug are engaged with an aperture defined in the collars attached to the streamer cable. A lever extends from the cylinder through the exterior of the shank so that an operator may rotate the cylinder, turning the cam in the aperture to a locking position. A spring applies a tensile force to the cylinder, drawing the cam down against the aperature, and pulling the shank tight against the collar.

Abstract: A marine speed log for providing an indication of the relative velocity of a vessel through water and an indication of the forward or reverse direction of travel. An output indication of total distance travelled can also be provided. The speed log is operable in both salt and fresh water without any change in calibration and incorporates a transducer having an air core. The speed log provides high sensitivity and high rejection of noise.