Abstract: A technique is designed to facilitate obtaining of acoustic data. The technique comprises traversing a tool through a subterranean formation from a first depth to subsequent depths. The tool receives a seismic signal during predetermined time windows. The seismic signal is generated by a seismic source which is activated at varying times relative to the predetermined time windows based on the depth of the tool.

Abstract: Methods and apparatuses are disclosed for generating three dimensional (3D) vertical seismic profiles (VSPs) in a more time efficient manner. The methods and apparatuses enable faster and more efficient VSP surveys than previous techniques. Real-time updating of the velocity model and real-time reflection point density calculations are carried out, which are used to determine the location of the next seismic source firing. In the event the data of a particular bin has an insufficient fold, common image points (CIPs) or reflection point density, additional source firings may be carried out prior to moving the source. Further, in the event the data of a particular bin is excessive in terms of the fold, CIPs or reflection point density before the planned source firings for the bin are completed, remaining source firings for that bin may be skipped to save time and improve the efficiency of the data collection.

Abstract: A technique is designed to facilitate obtaining of acoustic data. The technique comprises traversing a tool through a subterranean formation from a first depth to subsequent depths. The tool receives a seismic signal during pre-determined time windows. The seismic signal is generated by a seismic source which is activated at varying times relative to the predetermined time windows based on the depth of the tool.

Abstract: A method is disclosed for more accurately determining the relative bearing angle of a directional receiver in a borehole using an existing three-dimensional (3D) geological model, one or more seismic sources and a three component (3C) directional receiver. A disclosed method includes: receiving direct compressional arrivals generated by multiple source events at the directional receiver disposed in the borehole; rotating the seismic data into the true earth frame using an estimated relative bearing angle; measuring a polarization vector of the rotated seismic data; estimating an incident ray vector of the direct compressional arrivals at the directional receiver using ray-tracing through the 3D model; calculating the weighted sum of an angular difference between the polarization vector and the incident ray vector; and adjusting the estimated relative bearing angle until the angular difference between the polarization and incident ray vectors is minimized.

Abstract: Methods and apparatuses are disclosed for generating three dimensional (3D) vertical seismic profiles (VSPs) in a more time efficient manner. The methods and apparatuses enable faster and more efficient VSP surveys than previous techniques. Real-time updating of the velocity model and real-time reflection point density calculations are carried out, which are used to determine the location of the next seismic source firing. In the event the data of a particular bin has an insufficient fold, common image points (CIPs) or reflection point density, additional source firings may be carried out prior to moving the source. Further, in the event the data of a particular bin is excessive in terms of the fold, CIPs or reflection point density before the planned source firings for the bin are completed, remaining source firings for that bin may be skipped to save time and improve the efficiency of the data collection.

Abstract: A method is disclosed for more accurately determining the relative bearing angle of a directional receiver in a borehole using an existing three-dimensional (3D) geological model, one or more seismic sources and a three component (3C) directional receiver. A disclosed method includes: receiving direct compressional arrivals generated by multiple source events at the directional receiver disposed in the borehole; rotating the seismic data into the true earth frame using an estimated relative bearing angle; measuring a polarization vector of the rotated seismic data; estimating an incident ray vector of the direct compressional arrivals at the directional receiver using ray-tracing through the 3D model; calculating the weighted sum of an angular difference between the polarization vector and the incident ray vector; and adjusting the estimated relative bearing angle until the angular difference between the polarization and incident ray vectors is minimized.

Abstract: An amah for a high speed seagoing multi hulled vessel, the amah having sides extending upwardly and outwardly from a base line, the sides having longitudinally extending vertically spaced stiffeners, the bow of the amah including a plate field comprising a plurality of sub plates each comprising a vertical plate secured along the centre line of the amah and supporting a horizontal plate secured to each side of the amah, whereby the planes of the horizontal plates of the sub plates step upwardly as the base line rakes upwardly towards the bow and the longitudinal stiffeners terminate and are secured to the horizontal plates.

Abstract: A support structure for auxiliary machinery in a seagoing vessel, the support structure comprising a trussed frame supporting a mounting plate at an elevated height above the bottom or deck of the vessel, the mounting plate being adapted to support auxiliary machinery, the trussed frame comprising beams arranged in triangles along the sides and ends of the frame, whereby the frame elevates the machinery and provides ready access to the underside of the machinery.

Abstract: An amah for a high speed seagoing multi hulled vessel, the amah having sides extending upwardly and outwardly from a base line, the sides having longitudinally extending vertically spaced stiffeners, the bow of the amah including a plate field comprising a plurality of sub plates each comprising a vertical plate secured along the centre line of the amah and supporting a horizontal plate secured to each side of the amah, whereby the planes of the horizontal plates of the sub plates step upwardly as the base line rakes upwardly towards the bow and the longitudinal stiffeners terminate and are secured to the horizontal plates.

Abstract: A support structure for auxiliary machinery in a seagoing vessel, the support structure comprising a trussed frame supporting a mounting plate at an elevated height above the bottom or deck of the vessel, the mounting plate being adapted to support auxiliary machinery, the trussed frame comprising beams arranged in triangles along the sides and ends of the frame, whereby the frame elevates the machinery and provides ready access to the underside of the machinery.

Abstract: The invention is a method for determining the orientation of a multi-component receiver where the preferred embodiment of the method makes use of an approximation of the relative bearing angle provided by a relative bearing sensor. The method comprises the steps of scanning various angles around the approximated relative bearing angle provided by the relative bearing sensor and for each scanned angle rotating the data into the true earth frame using a given scanned angle and measuring the polarization angle of the rotated data in the horizontal plane and calculating a weighted sum of the differences between the source azimuth and the estimated azimuth from the polarization.

Abstract: A seagoing vessel having a length of between 45 and 175 meters and designed to operate at speeds of between 25 and 70 knots, the vessel comprising a single main hull with stabilising amahs positioned on either side, wherein the hydrostatic value of GM determined in the transverse plane lies between 0.5 and 5 meters, the vessel being shaped above the designed waterline such that the righting lever (GZ) curve as the vessel heels meets the following requirements: the area (b) bounded by the GZ curve plotted on the heeling axis between the angle of flooding and the heeling lever associated with a specific gust of wind is greater in value than the area (a) bounded by the GZ curve plotted on the heeling axis between the heeling lever associated with the specific gust of wind and an angle associated with the amount of roll of the vessel to windward under the action of the waves.

Abstract: The invention is a method for determining the orientation of a multi-component receiver where the preferred embodiment of the method makes use of an approximation of the relative bearing angle provided by a relative bearing sensor. The method comprises the steps of scanning various angles around the approximated relative bearing angle provided by the relative bearing sensor and for each scanned angle rotating the data into the true earth frame using a given scanned angle and measuring the polarization angle of the rotated data in the horizontal plane and calculating a weighted sum of the differences between the source azimuth and the estimated azimuth from the polarization.

Abstract: A seagoing vessel having a length of between 45 and 175 metres and designed to operate at speeds of between 25 and 70 knots, the vessel comprising a single main hull with stabilising amahs positioned on either side, wherein the hydrostatic value of GM determined in the transverse plane lies between 0.