摘要:
Apparatus, systems and methods for calculating position of marine seismic acoustic receivers, and for estimating sound velocity profile of a fluid, are disclosed. One position calculation system includes a vessel, two or more vessel hull-mounted transmitters, a plurality of acoustic receivers on a cable being deployed from the vessel into the fluid, and a calculation unit. The calculation unit may be adapted to calculate position of the receivers, and may be used in calculating the sound velocity profile in the fluid and correcting raw seismic data. It is emphasized that this abstract is provided to comply with the rules requiring an abstract, which will allow a searcher or other reader to quickly ascertain the subject matter of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims. 37 CFR 1.72(b).
摘要:
Apparatus and methods for enhancing knowledge of the angle of attack of a streamer steering device are described, one apparatus comprising a seismic streamer having an orientation member including a body and at least one control surface; a sensor of the body adapted to measure a parameter indicative of angle of attack of the body; and a controller for adjusting the control surface based on at least the measured parameter. It is emphasized that this abstract is provided to comply with the rules requiring an abstract, which will allow a searcher or other reader to quickly ascertain the subject matter of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims.
摘要:
In a method for integrity monitoring in position determination by means of the Global Positioning System (GPS), especially by means of differential GPS (DGPS) or multi-station DGPS, wherein there is employed a monitor station (M) with a first GPS receiver, provided at a location with a known geographical position, GPS-based position measurement results are transferred on a communication line from the monitor station (M) to a user location (F) the integrity of whose geographical position has to be monitored by means of a second GPS receiver provided at the location (F). A space vector between the location of the monitor station (M) and the location (F) is determined by means of the position measurement results for the location (F) and the monitor station (M), whereupon the degree of agreement is determined between the position for the location (F), the space vector and the known position of the monitor station (M), the degree of agreement being required to correspond to a maximum error in the position for the user location (F).
摘要:
A method for determining the position of at least two seismic streamers (S.sub.1, S.sub.2) in a reflection seismic measuring system, wherein hydroacoustic distance measurements are used which are taken by means of acoustic transceivers provided in vessels (1), buoys (8), floats (5), seismic sources (2) and in the seismic streamers (S.sub.1, S.sub.2). Absolute reference positions are determined by position determining equipment provided in at least two locations, for instance, on a vessel (1) or a float (5). The acoustic transceivers and the position determining equipment form a three-dimensional structure. The position determination takes place by trilateration between the acoustic transceivers and the determination of at least two reference positions so that there is no dependency on compass bearings or optical visibility, and high redundancy is obtained. The method is particularly suited for application in connection with three-dimensional marine seismic surveys. The method may be integrated with suitable surface navigation systems in order to find the reference positions and provide absolute positions at any point within a marginal error of 5 to 10 m.
摘要:
An electromagnetic source for electromagnetic survey of a subsea formation includes a towfish configured to be towed by a surface vessel; a plurality of electrodes attached to the towfish; and an acoustic ranging system having acoustic components individually attached to each of the towfish and the plurality of electrodes, wherein the acoustic ranging system is configured to determine a geometry of the plurality of electrodes.
摘要:
Methods and systems for determining position of marine seismic spread components are disclosed. One method comprises exposing an underwater marine seismic spread component to an optical device, and calculating geometry of the spread component using at least some of the data obtained by the optical device, for example travel time for an optical signal to travel to and return from one or more spread elements in the spread component. The optical device may comprise one or more laser scanners, cameras, or laser scanners and cameras. The spread component may be a marine seismic source, a marine seismic streamer cable, and the like. This abstract allows a searcher or other reader to quickly ascertain the subject matter of the disclosure. It will not be used to interpret or limit the scope or meaning of the claims. 37 CFR 1.72(b).
摘要:
Methods and systems for determining position of seismic sources and receivers are disclosed. Signals received by a first antenna are processed to determine its 3D coordinate position. Signals received by the first antenna and a second antenna are combined and processed to estimate a spatial vector between the first and second antennas. The spatial vector is added to the 3D coordinate position of the first antenna to provide a 3D coordinate position of the second antenna. Using the 3D coordinate position of the second antenna, a 3D coordinate position of a seismic source unit or receiver may be calculated, as well as a vertical correction for reflected seismic signals received by the receiver. This abstract allows a searcher or other reader to quickly ascertain the subject matter of the disclosure. It will not be used to interpret or limit the scope or meaning of the claims. 37 CFR 1.72(b).
摘要:
Apparatus and methods for enhancing knowledge of the angle of attack of a streamer steering device are described, one apparatus comprising a seismic streamer having an orientation member including a body and at least one control surface; a sensor of the body adapted to measure a parameter indicative of angle of attack of the body; and a controller for adjusting the control surface based on at least the measured parameter. It is emphasized that this abstract is provided to comply with the rules requiring an abstract, which will allow a searcher or other reader to quickly ascertain the subject matter of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims.
摘要:
Methods and systems for determining position of seismic sources and receivers are disclosed. Signals received by a first antenna are processed to determine its 3D coordinate position. Signals received by the first antenna and a second antenna are combined and processed to estimate a spatial vector between the first and second antennas. The spatial vector is added to the 3D coordinate position of the first antenna to provide a 3D coordinate position of the second antenna. Using the 3D coordinate position of the second antenna, a 3D coordinate position of a seismic source unit or receiver may be calculated, as well as a vertical correction for reflected seismic signals received by the receiver. This abstract allows a searcher or other reader to quickly ascertain the subject matter of the disclosure. It will not be used to interpret or limit the scope or meaning of the claims. 37 CFR 1.72(b).
摘要:
Methods and systems for determining position of marine seismic spread components are disclosed. One method comprises exposing an underwater marine seismic spread component to an optical device, and calculating geometry of the spread component using at least some of the data obtained by the optical device, for example travel time for an optical signal to travel to and return from one or more spread elements in the spread component. The optical device may comprise one or more laser scanners, cameras, or laser scanners and cameras. The spread component may be a marine seismic source, a marine seismic streamer cable, and the like. This abstract allows a searcher or other reader to quickly ascertain the subject matter of the disclosure. It will not be used to interpret or limit the scope or meaning of the claims.