Abstract: A method for obtaining zero-offset and near zero offset seismic data from a marine survey, with separation of direct arrival information and reflectivity information, the method including: modeling a direct arrival estimate at a passive near-field hydrophone array by using a notional source separation on active near-field hydrophone data; generating reflection data for the passive near-field hydrophone array by subtraction of the modeled direct wave from data recorded by the passive near-field hydrophone array; generating near zero-offset reflectivity traces by stacking the reflection data for the passive near-field hydrophone array on a string-by-string basis or on a combination of strings basis.

Abstract: Method for obtaining zero offset or near zero offset data in a marine seismic streamer survey. An acoustic transmitter (41) is attached to one of the buoys (14 or 16) that provide flotation to each streamer (12) and tow umbilical (13). The acoustic transmitters, or single transmitter in the case of a 2-D survey, may be fired (71-73) before each shot from the survey air guns. The response to the acoustic transmitters recorded by the near sensors in each streamer, or by a water break sensor if provided, will be a near-zero to zero-offset record of the shallow subsurface below the water bottom.

Abstract: A method for obtaining zero-offset and near zero offset seismic data from a marine survey, with separation of direct arrival information and reflectivity information, the method including: modeling a direct arrival estimate at a passive near-field hydrophone array by using a notional source separation on active near-field hydrophone data; generating reflection data for the passive near-field hydrophone array by subtraction of the modeled direct wave from data recorded by the passive near-field hydrophone array; generating near zero-offset reflectivity traces by stacking the reflection data for the passive near-field hydrophone array on a string-by-string basis or on a combination of strings basis; generating reflectivity information at the active near-field hydrophone array by subtracting the direct arrival estimate modeled using the notional source separation from the active near-field hydrophone data; and generating an estimate of zero-offset reflectivity traces by calculating a cross-correlation between th

Abstract: Method for estimating source signature of a marine seismic source array in a naturally band-limited subsurface region, for designature processing of resulting seismic data. Direct arrivals identified in the streamer receivers' records (131) provide a far-field estimate of the source signature, provided that the subsurface naturally limits frequencies to below the first notch frequency in the amplitude response of the seismic streamer receiver array. Processing of the direct arrivals may include move out or alignment correction (132), signal enhancement (133), summing of direct arrival traces over all offsets (134), windowing or tapering of direct arrivals (135), and deterministic corrections to the combined direct arrivals to compensate for ghosting and streamer array effects (136).

Abstract: Method for obtaining zero offset or near zero offset data in a marine seismic streamer survey. An acoustic transmitter (41) is attached to one of the buoys (14 or 16) that provide flotation to each streamer (12) and tow umbilical (13). The acoustic transmitters, or single transmitter in the case of a 2-D survey, may be fired (71-73) before each shot from the survey air guns. The response to the acoustic transmitters recorded by the near sensors in each streamer, or by a water break sensor if provided, will be a near-zero to zero-offset record of the shallow subsurface below the water bottom.

Abstract: Method for estimating source signature of a marine seismic source array in a naturally band-limited subsurface region, for designature processing of resulting seismic data. Direct arrivals identified in the streamer receivers' records (131) provide a far-field estimate of the source signature, provided that the subsurface naturally limits frequencies to below the first notch frequency in the amplitude response of the seismic streamer receiver array. Processing of the direct arrivals may include move out or alignment correction (132), signal enhancement (133), summing of direct arrival traces over all offsets (134), windowing or tapering of direct arrivals (135), and deterministic corrections to the combined direct arrivals to compensate for ghosting and streamer array effects (136).

Abstract: The described invention relates to a method for acquiring seismic data in icy waters comprising positioning a fixed structure or movable vessel (102) at or near an established water opening; deploying into the water opening, from said structure or vessel one or more ROV or AUV units (104), said ROV or AUV units remaining connected to said structure or vessel; operating the one or more ROV or AUV units to deploy seismic sensors recording equipment (106) and/or one or more seismic source equipment (108) on or near the water bottom; generating and applying control signals to one or more of the more ROV or AUV units to generate and to record seismic signals (110); operating the one or more ROV or AUV units on the water bottom to move (114) and/or recover (116) the seismic source equipment and/or seismic sensors recording.

Abstract: Method for acquiring zero offset data from a marine seismic survey. Seismic data are recorded using source signature monitor receivers located very near the air guns or other sources (81). The recorded data are sorted into common-source gathers (82). A common trace is computed that is common to each gather (83). The common trace is subtracted from each trace in each gather (84), resulting in approximately zero-offset data.

Abstract: Method for separating different seismic energy modes in the acquisition (65) of seismic survey data by using sensors that preferentially record a single mode (63), optionally combined with a source that preferentially transmits that mode.

Abstract: The described invention relates to seismic acquisition means for use in shallow water marine environments, comprising: (a) a vessel (1) having at least one hull (25); (b) one or more shaker (13) and baseplate (12) assemblies affixed to the vessel by two or more rigid supporting elements (11) adapted to be capable of lowering said assemblies from the vessel hull to a shallow water bottom (14) and of raising said assemblies from the shallow water bottom to the hull; and, wherein each of said assemblies comprise one or more vibrator units mounted on a baseplate that is adapted to rest upon the shallow water bottom and to transmit vibratory signals from the vibrator units into said water bottom. The described invention provides a high-amplitude, broadband seismic signal, provides high data-production rates, couples energy directly into the earth and minimizes damage to the water bottom.

Abstract: Method and apparatus for producing a bubble curtain with a diversity of bubble diameters for purposes such as modifying the characteristics of a seismic source used in marine seismic surveys. Bubble generating elements are used that combine porous wall material with discrete holes (91) to create a curtain of diverse-sized bubbles (92).

Abstract: Method and apparatus for producing a bubble curtain with a diversity of bubble diameters for purposes such as modifying the characteristics of a seismic source used in marine seismic surveys. Bubble generating elements are used that combine porous wall material with discrete holes (91) to create a curtain of diverse-sized bubbles (92).

Abstract: Method and apparatus for producing a bubble curtain with a diversity of bubble diameters for purposes such as suppressing surface-related multiple reflections in marine seismic surveys. Bubble generating elements are used that combine porous wall material with discrete holes.

Abstract: Method for conducting a seismic survey (23) wherein the acquisition parameters are modified as the survey progresses using information (24) from sensors located to monitor structures and fixtures located in the survey area. The sensor output is compared to acceptable levels, and acquisition parameters such as the seismic source strength are adjusted (26) to prevent exceeding the acceptable levels. An automated arbitration scheme (22) is used to resolve conflicting system goals within survey resource constraints.

Abstract: Method for acquiring zero offset data from a marine seismic survey. Seismic data are recorded using source signature monitor receivers located very near the air guns or other sources (81). The recorded data are sorted into common-source gathers (82). A common trace is computed that is common to each gather (83). The common trace is subtracted from each trace in each gather (84), resulting in approximately zero-offset data.

Abstract: The described invention relates to seismic acquisition means for use in shallow water marine environments, comprising: (a) a vessel (1) having at least one hull (25); (b) one or more shaker (13) and baseplate (12) assemblies affixed to the vessel by two or more rigid supporting elements (11) adapted to be capable of lowering said assemblies from the vessel hull to a shallow water bottom (14) and of raising said assemblies from the shallow water bottom to the hull; and, wherein each of said assemblies comprise one or more vibrator units mounted on a baseplate that is adapted to rest upon the shallow water bottom and to transmit vibratory signals from the vibrator units into said water bottom. The described invention provides a high-amplitude, broadband seismic signal, provides high data-production rates, couples energy directly into the earth and minimizes damage to the water bottom.

Abstract: The described invention relates to a method for acquiring seismic data in icy waters comprising positioning a fixed structure or movable vessel (102) at or near an established water opening; deploying into the water opening, from said structure or vessel one or more ROV or AUV units (104), said ROV or AUV units remaining connected to said structure or vessel; operating the one or more ROV or AUV units to deploy seismic sensors recording equipment (106) and/or one or more seismic source equipment (108) on or near the water bottom; generating and applying control signals to one or more of the more ROV or AUV units to generate and to record seismic signals (110); operating the one or more ROV or AUV units on the water bottom to move (114) and/or recover (116) the seismic source equipment and/or seismic sensors recording.

Abstract: Method and apparatus for producing a bubble curtain with a diversity of bubble diameters for purposes such as suppressing surface-related multiple reflections in marine seismic surveys. Bubble generating elements are used that combine porous wall material with discrete holes.

Abstract: Method for conducting a seismic survey (23) wherein the acquisition parameters are modified as the survey progresses using information (24) from sensors located to monitor structures and fixtures located in the survey area. The sensor output is compared to acceptable levels, and acquisition parameters such as the seismic source strength are adjusted (26) to prevent exceeding the acceptable levels. An automated arbitration scheme (22) is used to resolve conflicting system goals within survey resource constraints.

Abstract: A technique for providing auxiliary conduits in multi-trip completions is disclosed. The technique has particular applicability to liner mounted screens which are to be gravel packed. In the preferred embodiment, a protective shroud is run with the gravel pack screens with the auxiliary conduits disposed in between. The auxiliary conduits terminate in a quick connection at a liner top packer. The gravel packing equipment can optionally be secured in a flow relationship to the auxiliary conduits so as to control the gravel packing operation. Subsequent to the removal of the specialized equipment, the production tubing can be run with an auxiliary conduit or conduits for connection down hole to the auxiliary conduits coming from the liner top packer for a sealing connection. Thereafter, during production various data on the well can be obtained in real time despite the multiple trips necessary to accomplish completion.