Abstract: Apparatus for seismic surveying a borehole by simultaneously measuring seismic signals at a plurality of elevations within the borehole. A resilient tubular member is filled with a liquid and the length of the tubular member is divided into several adjacent series arranged chambers. A sensor for receiving the seismic signal is placed within each chamber, and means are provided for measuring and storing the signal received by each of the sensors. The sensors are suspended within the tubular member by a stress member, and the stress member is suspended from a bulkhead which divides the adjacent chambers, and which isolates the chambers one from the other. This arrangement of parts provides a unique structure which enables geologizing a borehole seismically in a new and unobvious manner.

Abstract: A gradiometer array of two or more sensors consists of a closed housing filled with a volume of fluid having a desired specific gravity. The sensors are freely suspended in the housing by flexible tethers. The sensors have different specific gravities such that one always sinks and the other floats. By that means, the sensors are self-aligning along an axis parallel to the gravitational vertical.

Abstract: I provide a combination land/bay cable capable for simultaneous use on land and in water-covered areas. When the cable section is placed in a water-covered area suitable for hydrophone use, a polarized plug containing an impedance matching transformer is detachably connected to a polarized socket. The transformer connects the hydrophones to a transmission line. If the cable is to be used on land, the transformer is unplugged deactivating the hydrophones and at least one geophone having a substantially identical plug is inserted in the socket. The plug connects the geophone to the transmission line and leaves the hydrophones inactive.

Abstract: In accordance with an illustrative embodiment of the present invention, a plug-in geophone case includes a body having an open top and a cavity that receives a seismic detector having positive and negative terminals, receptacles on opposite sides of said body for plugging the case into leader cables, a set of three connector pins molded in the case adjacent each receptacle, one end of each pin extending into a receptacle and the other end extending into a recess in the body adjacent one of said terminals, a cover plate for closing the open top of said case, and means for sealingly fastening a connector plug in each of said receptacles, said plugs and receptacles having mating means to prevent connection with the wrong polarity.

Abstract: A cartridge carrying electronic or other components is removably mounted in the breech of an adaptor module connected either in a streamer section or between opposing ends of adjacent streamer sections of a towed array. The adapter module is provided with channels for loosely guiding all but one strain member, one strain member being clamped to the module, with the longitudinal axis of the module breech being established by the longitudinal axis of the clamped strain member such that alignment of the cartridge is uniquely keyed to the single clamped strain member, the loose mounting of the unclamped strain members preventing differential forces being applied to the adapter module. In one embodiment, a spring-loaded pin and shuttle connector arrangement severs connection for an empty breech and provides for both point contact to an inserted cartridge and relatively long leakage paths so that any entrained sea water will not short out the adapter module or connector system.

Abstract: Apparatus for shear wave logging of formations adjacent a borehole wherein a tubular apparatus is specifically constructed for sympathetic movement with the borehole in response to low frequency horizontal shear waves. The apparatus consists of tubular frame structure with end members including housings for rigid seating of orthogonal pairs of horizontal wave detectors. Outer sleeve structure may be utilized for buoyancy adjustment.

Abstract: A cable system for carrying out seismic operations, comprising a multi-conductor cable built with multiple segments, each segment terminated with identical connector plugs. Each segment having a selected number P of take-outs for accepting P seismic signals. The group of P seismic signals from the take-outs are multiplexed in each cable segment, and travel over a single conductor pair in the successive segments to the recording truck, where they are demultiplexed, and as reconstituted signals, are processed and recorded.

Abstract: An arrangement of a plurality of individual gas expansible marine sources, wherein the positive portions of the primary shock waves are additive in effect, the negative portions of the primary shock waves are not additive in effect and the positive and negative portions of the after-shock or bubble occurrences also are not additive in effect.

Abstract: A marine seismic streamer cable having both pressure responsive and acceleration responsive transducers disposed therein. The accelerometer responds to acceleration along one axis regardless of its orientation about the other axis. The accelerometer is mounted in the streamer cable and responds to accelerations produced by a seismic source but is insulated from the noise and motion produced as the streamer cable is towed through the water.

Abstract: Disclosed is a system for acoustic noise logging in a production well which includes up-hole components and down-hole components including at least two sonic detectors, the up-hole and down-hole components being linked together by a four-wire interconnecting means. In addition, the down-hole components include at least three additional parameter detectors. These additional parameter detectors may include a temperature detector, a conductivity detector and a location detector. The first of these detectors produces a frequency proportional to, for example, temperature. The second detector frequency modulates the temperature signal, for example, in response to location. The third detector amplitude modulates the signal depending on whether or not a conductivity threshold has been exceeded.The foregoing permits simultaneous monitoring of a plurality of down-hole parameters simultaneously without the necessity for multiplexing and yet employs only a four wire interconnecting means.

Abstract: A hydraulically-powered yo-yo reel for handling a marine seismic cable in shallow water. At the beginning of a recording episode, a partially reeled-in seismic cable is released to drift to a standstill behind a ship. Data are recorded. The cable is then accelerated to match the ships's velocity. Following the initial acceleration, the cable is superaccelerated as it is partially reeled in. A microprocessor adjusts a dwell time between recording episodes to compensate for small variations in the ship's velocity.

Abstract: A method of locating near-surface underground chambers, rooms, caves, pits, tubes, faults in surface rocks, and the like, using acoustic techniques is disclosed. For mapping large areas, a survey grid for transmitter transducer placement first is laid out over the area of interest.A transmitting transducer is coupled to the bedrock at one of the grid sites, and acoustic waves are generated in the earth by operation thereof. Portable acoustic receiving means, including a receiving transducer, are used to detect acoustic waves from the transmitter at a plurality of receiving sites surrounding the transmitting station. Transmitted acoustic waves from the transmitting site received by the receiving transducer are converted to electrical signals by the receiving transducer and recorded for subsequent use. Following operation of the receiving means at each receiving site surrounding the transmitter transducer, the received signals are compared to determine any differences in their magnitudes.

Abstract: A seismic instrument sensing unit mounting assembly includes an outer housing having an inner spherical chamber with an inner housing having a low center of gravity and a semi-spherical bottom surface cooperatively engaging the spherical walls of the outer housing for sliding thereon to the lowermost point within the spherical chamber and thereby maintain a vertical orientation. A sensing unit having a sensing axis with a preferred vertical orientation mounted within the inner housing such that the unit is maintained with the sensing axis in the vertical orientation regardless of the position or orientation of the outer housing. A number of these self-erecting sensing units are connected together by a suitable tension and conductor cables and are deployed and picked up by a method employing mechanical means. The string of units are rapidly layed out upon the surface of the earth without regard to the orientation of the outer housing.

Abstract: Sets of at least three geophones are oriented in different directions perpendicular to the longitudinal axis of a seismic cable in which they are assembled, so that at least one geophone in each set will detect substantially vertically-propagating reflected seismic signals when the cable is rotated in any orientation about its longitudinal axis. Arrangements may be provided to selectively enable the one geophone of each set that has its axis most nearly oriented to the vertical.

Abstract: A system for marine seismic exploration has arrays of sources and receivers which discriminate against horizontal traveling source-generated noise. Directive arrays of sources or receivers have a length which is longer than the wavelength of the lowest frequency of the seismic pulse. The spacing between the elements in the array is less than the wavelength of the highest characteristic frequency in the seismic pulse.

Abstract: A method for generating and detecting seismic shear wave energy in the earth are disclosed useful for determining shear wave velocities in localized regions in the earth at sites where foundations of large civil engineering structures are proposed or earth embankments and dams have been built, thereby providing information affecting the basic dynamic design parameters for constructing or evaluating the project and obtaining earthquake resistant design. An airgun of elongated generally cylindrical configuration and having a single discharge port opening out radially on one side only for abruptly releasing compressed air in a direction perpendicular to the axis of the airgun is lowered into a borehole in a manner and by apparatus to control the direction in azimuth at which this single lateral discharge port is aimed.

Abstract: A land surface seismic prospecting cable which can be towed on the surface of the earth along seismic survey lines. The cable is used to transport, position, protect, house, or attach sensors used for making geophysical and environmental measurements. The cable apparatus may comprise a plurality of segments each interconnected by an electrical connector and each segment having a plurality of sensors associated therewith. The outputs of the signals from the sensors are carried by way of a multiconductor wire cable within the seismic cable to a seismic recorder. After an acoustic disturbance is produced and the seismic information is recorded, the towed land cable or land streamer is towed intact to the next shooting site which saves a great deal of time and allows greater areas to be covered in a predetermined time period.

Abstract: Seismic exploration method applicable to marine surveys. It involves making a dual spread of detectors which are spaced apart vertically. The signals received at the uppermost spread are delayed sufficiently to make downgoing energy signals in time coincidence with downgoing energy signals from the lower spread. Then the signals from both spreads are algebraically combined so as to cancel downgoing energy signals only.