A marine seismic exploration method and system comprised of continuous recording, self-contained ocean bottom pods characterized by low profile casings. An external bumper is provided to promote ocean bottom coupling and prevent fishing net entrapment. Pods are tethered together with flexible, non-rigid, non-conducting cable used to control pod deployment. Pods are deployed and retrieved from a boat deck configured to have a storage system and a handling system to attach pods to cable on-the-fly. The storage system is a juke box configuration of slots wherein individual pods are randomly stored in the slots to permit data extraction, charging, testing and synchronizing without opening the pods. A pod may include an inertial navigation system to determine ocean floor location and a rubidium clock for timing. The system includes mathematical gimballing. The cable may include shear couplings designed to automatically shear apart if a certain level of cable tension is reached.

Method and apparatus for seismic data acquisition

The present invention is a method of processing seismic data in which one or more seismic vibrators are activated with one or more pilot signals and vibrator motions are recorded along with seismic data. Vibrator signatures (4) are computed from measured vibrator motions (2), such as the ground force signal. A desired impulse response (5) is specified from either a measured vibrator motion (2) or from test data or field data from a location near the location from which the seismic data was acquired. A deconvolution filter (8) is computed from the impulse response (5) and from the vibrator signatures (4) from multiple vibrators and sweeps (1). The deconvolution or deconvolution and separation filter (8) is used to process the seismic data. The vibrators are then moved to a new location, and the activation is repeated.

Shaped high frequency vibratory source

A method and apparatus for deployment and retrieval of ocean bottom seismic receivers. In one embodiment the apparatus comprises a carrier containing a plurality of receivers attached to a remotely operated vehicle (ROV). The carrier comprises a frame in which is mounted a structure for seating and releasing said receivers. The structure may comprise a movable carousel or a movable conveyor or fixed parallel rails or a barrel. In the case of the barrel the receivers are axially stacked therein. The structure is disposed to deliver said receivers to a discharge port on said frame where the receivers are removable from said carrier. The apparatus includes a discharge mechanism for removing said receivers from said carrier.

Method and apparatus for deployment of ocean bottom seismometers

A seismic exploration method and unit comprised of continuous recording, self-contained wireless seismometer units or pods. The self-contained unit may include a tilt meter, a compass and a mechanically gimbaled clock platform. Upon retrieval, seismic data recorded by the unit can be extracted and the unit can be charged, tested, re-synchronized, and operation can be re-initiated without the need to open the unit's case. The unit may include an additional geophone to mechanically vibrate the unit to gauge the degree of coupling between the unit and the earth. The unit may correct seismic data for the effects of crystal aging arising from the clock. Deployment location of the unit may be determined tracking linear and angular acceleration from an initial position. The unit may utilize multiple geophones angularly oriented to one another in order to redundantly measure seismic activity in a particular plane.

Method and apparatus for land based seismic data acquisition

The invention method for attenuating noise in the seismic data traces (51), comprises the computer processing steps of processing the move out velocity of the coherent noise data (33), that is different from the move out velocity of the seismic data (33) with the method steps of shorting the seismic data traces into a common receiver order and with the method steps of using the difference in the move out velocities to separate the coherent noise from the seismic data signal (59). The method is used in suppressing noise (60) in two and four-receiver component ocean bottom, (OCB) cable seismic data (51).

Method for attenuating noise in seismic data

An apparatus and method for removing the distortion in marine seismic data resulting from the motion of the ship. The ship trails one or more seismic sources and receivers and moves forward at a known velocity. The seismic sources emit seismic waves that travel through the water and reflect off interfaces between rock formations below the ocean floor. The motion of the sources and receivers introduces distortion in the recorded seismic data that can be modeled using Doppler theory. The data preferably is corrected for source motion independently from the correction for receiver motion. The seismic data is first corrected for receiver motion and then for source motion. The technique for correcting for source motion includes correlating the receiver-corrected data with a reference sweep signal, performing an F-K transform, performing an inverse F-K transform on a selected subset of the F-K transformed data, and computing appropriate correction filters for the data resulting from the inverse F-K transform. This process is repeated for all subsets of F-K transformed data and the resulting filtered data are summed together.

Method and apparatus for correcting effects of ship motion in marine seismology measurements

Le dispositif de correction comprend un systeme de mesure sismique et de traitement, ainsi qu'au moins une source sismique un recepteur sismique, un organe d'entree utilisateur et un organe d'affichage qui sont couples a ce systeme.Le systeme de mesure sismique et de traitement comporte une source 112, une unite d'interface de recepteur, une unite de traitement et une unite de stockage; il corrige le deplacement de la source en calculant une transformation des donnees sismiques captees par les recepteurs 1 14, ainsi qu'une transformation inverse des donnees transformees d'une tranche presentant un pendage constant 122. Application a la sismologie a faible amplitude vibratoire ( " HFVS " ) menageant l'environnement marin.

Allen Kenneth Paul

Papers

Method and apparatus for correcting effects of ship motion in marine seismology measurements

Procede et dispositif pour corriger les effets des deplacements du navire dans les mesures de sismique maritime