Abstract: A heave suppressed, floating offshore drilling and production platform comprises vertical columns, lateral trusses connecting adjacent columns, a deep-submerged horizontal plate supported from the bottom of the columns by vertical truss legs, and a topside deck supported by the columns. The lateral trusses connect adjacent columns near their lower end to enchance the structural intergrity of the platform. During the launch of the platform and towing in relatively shallow water, the truss legs are stowed in shafts within each column, and the plate is carried just below the lower ends of the columns. After the platform has been floated to the deep water drilling and production site, the truss legs are lowered from the column shafts to lower the plate to a deep draft for reducing the effect of wave forces and to provide heave and vertical motion resistance to the platform.

Abstract: Methods and systems for administering redundant cancellations of orders for securities. Canceling orders for securities in an automated securities trading broker-dealer system. Receiving new cancellations from clients and searching a cancellation queue for cancellations corresponding to the new cancellations. If a corresponding cancellation is found in the cancellation queue, the redundancy count of the corresponding cancellation is incremented in the cancellation queue and the new cancellation is discarded. If a cancellation corresponding to the new cancellation is not found in the cancellation queue, a copy of the new cancellation is placed in the cancellation queue and the new cancellation is sent to the market. Embodiments periodically scanning the cancellation queue for cancellations having a redundancy count greater than zero, decrementing the redundancy count for such cancellations. Some embodiments issue additional cancellations dependent upon receipt of acknowledgments of earlier cancellations.

Abstract: For a spar type floating platform having risers passing vertically through the center well of a spar hull, there is provided apparatus for supporting the risers from a gimbaled table supported above the top of the spar hull. The table flexibly is supported by a plurality of non-linear springs attached to the top of the spar hull. The non-linear springs compliantly constrain the table rotationally so that the table is allowed a limited degree of rotational movement with respect to the spar hull in response to wind and current induced environmental loads. Larger capacity non-linear springs are located near the center of the table for supporting the majority of the riser tension, and smaller capacity non-linear springs are located near the perimeter of the table for controlling the rotational stiffness of the table. The riser support table comprises a grid of interconnected beams having openings therebetween through which the risers pass.

Abstract: A method and device for processing a seismic survey data set including: an actual source location, an actual receiver location, and an actual reflection event location is provided. The actual source location and actual receiver location are over a first layer having a first layer velocity and a first layer ray parameter, and over a second layer having a second layer velocity different from the first layer velocity and a second layer ray parameter different from the first layer ray parameter. The actual reflection event location is located below the first layer. The method comprises: providing the first layer velocity; providing the second layer velocity; providing the first layer ray parameter; providing the second layer ray parameter; determining a correction factor for the position of a ray path end dependant upon the first and second layer velocities and the first and second layer ray parameters; and applying the correction factor to the ray path end, wherein a ray path-corrected ray path end is provided.

Abstract: A device (10) for connecting a towed seismic streamer (6) to a lead-in towing cable (7) and to a towing wire (8) is provided. The device (10) comprises a first connecting part (11) with coupling means (11A) for connecting to the foremost end of the streamer (6), a second connecting part (12) with coupling means (12A) for connecting to the end of the lead-in towing cable (7), and an intermediate part (15) having two connecting points (16, 17) for rotatable connection with the first and second connecting parts (11, 12), respectively. The device (10) also comprises a rotatable fastening member (20) for connecting to the towing wire (8) and a flexible conducting means (21) between the opposite ends of connecting parts (11, 12) for electric connection between streamer (6) and lead-in towing cable (7). The angles between the streamer (6), the lead-in towing cable (7), and the towing wire (8) are variable within limits.

Abstract: Methods and systems are provided for orientation of multicomponent geophones, for rotating traces, and for correcting polarity differences between traces. According to an example embodiment, a receiver orientation angle is assigned, based on a determination of an angle between one or more horizontal components and one or more sources.

Abstract: Device for the adjustment of buoyancy of a seismic cable comprising a main part (1) adapted to firm, integrated mounting into a chosen point in the length of the cable, the main part (1) comprising fastening means (3,4) for one or more weight or buoyancy elements (2) and one or more exchangeable weight or buoyancy elements (2) adapted to being mounted into the main part (1).

Abstract: A process comprising: attaching a first end of a chain to the tendon; securing a second end of the chain to the platform. A mechanism comprising: a chain which is attached to the tendon; and a stopper for attaching the chain to the platform. A tension-leg platform (TLP) comprising: a platform for production operations which floats on the surface of the sea; an anchor which attaches to the sea floor; a flexible tendon which connects to the anchor on the sea floor; and a mechanism for attaching the flexible tendon to the platform.

Abstract: A process comprising: generating a stabilizing moment, before the platform is secured and tensioned to the sea floor, wherein the generating vertically aligns the central axis of the TLP; and reducing the size of the TLP in the wave zone, after a tendon of the platform is secured to the sea floor. A device comprising: a generator of a stabilizing moment, before the platform is secured and tensioned to the sea floor, wherein the generator vertically aligns the central axis of the TLP; and a reducer of the size of the TLP in the wave zone, after a tendon of the platform is secured to the sea floor.

Abstract: A method for monitoring production mineral reservoirs, the method comprising: permanently installing a geophone in a borehole; generating a first set of seismic waves; receiving a first set of seismic data with the geophone; recording the first set of data of said receiving a first set of seismic data; generating a second set of seismic waves after sufficient time has passed for conditions in the reservoir to have changed from the generating a first set of seismic waves; receiving a second set of seismic data with the geophone; and recording the second set of seismic data of said receiving a second set of seismic data. A method for installing instruments below the surface of the earth, the method comprising: drilling a borehole with a drill apparatus; inserting an instrument in the borehole; and permanently fixing the instrument in the borehole.

Abstract: Drive assembly for acoustic sources with vibrating surfaces (1) capable of being set in vibrational motion, especially for use in seismic studies, comprising a frame (4) comprising at least one preferably centrally positioned drive part (3, 13). The drive assembly also comprises: two or more fastening devices (2) mounted in relation to the sound emitting surfaces (1) and positioned on opposite sides of the frame (4); two or more flexible transmission elements (5) connecting the fastening devices (2) to each other and extending on both sides of the axis between the two fastening devices;5 two or more second drive parts (6, 7, 16, 17) connected to the transmission elements (5) and positioned in cooperation with said first drive parts (3, 13) in order to make electromagnetic drives; and that each of the electromagnetic drives are adapted to provide a controlled oscillating relative motion between the related drive parts (3, 6, 7, 16, 17).

Abstract: A method for monitoring production mineral reservoirs, the method comprising: permanently installing a geophone in a borehole; generating a first set of seismic waves; receiving a first set of seismic data with the geophone; recording the first set of data of said receiving a first set of seismic data; generating a second set of seismic waves after sufficient time has passed for conditions in the reservoir to have changed from the generating a first set of seismic waves; receiving a second set of seismic data with the geophone; and recording the second set of seismic data of said receiving a second set of seismic data. A method for installing instruments below the surface of the earth, the method comprising: drilling a borehole with a drill apparatus; inserting an instrument in the borehole; and permanently fixing the instrument in the borehole.

Abstract: It has been found that, rather than merely recording raw data on the seismic vessel for processing on shore, the performance of certain processing on the vessel at a particular time addresses the problems. Specifically, performing pre-stack time migration on raw data as it is being recorded on a seismic ship provides the information needed for quality control of the acquisition process, as well as providing a starting point for velocity analysis in preparation for later depth migration.

Abstract: A method for monitoring production mineral reservoirs, the method comprising: permanently installing a geophone in a borehole; generating a first set of seismic waves; receiving a first set of seismic data with the geophone; recording the first set of data of said receiving a first set of seismic data; generating a second set of seismic waves after sufficient time has passed for conditions in the reservoir to have changed from the generating a first set of seismic waves; receiving a second set of seismic data with the geophone; and recording the second set of seismic data of said receiving a second set of seismic data. A method for installing instruments below the surface of the earth, the method comprising: drilling a borehole with a drill apparatus; inserting an instrument in the borehole; and permanently fixing the instrument in the borehole.

Abstract: A system for transmitting signals between a plurality of towed sensor streamers and a seismic vessel, the system comprising: a plurality of seismic streamers, wherein each streamer of the plurality of seismic streamers comprises: a leading end, a trailing end, a plurality of sensors located therein and a transmitter of seismic signals received by the plurality of sensors to a terminal located in the leading end of the streamer; at least one spreader located between the leading ends of two streamers of the plurality of seismic streamers, the spreader comprising: connectors for connection to the terminals of the streamers, a spreader terminal, and a spreader transmitter of signals between the connectors and the spreader terminal; a lead-in having a lead-in connector for connecting to the spreader terminal and a transmitter of signals between the lead-in connector and the seismic vessel.

Abstract: A method for eliminating the influence of multiple reflections in seismic data by determining an up going and down going vector wave-field from the vector wave-field, determining a product of the free surface refection coefficient and the down going vector wave-field, and adding the product to the up going vector wave-field. Also provided is a method for eliminating the effects of receiver coupling from seismic data taken in a survey by describing a first cross-equalization filter as a function of the reverberation period, describing a second cross equalization filter as a function of the seismic data, deriving an inverse coupling filter as a function of the first cross-equalization filter and the second-equalization filter, and applying the coupling filter to the seismic data.

Abstract: A method of suppression of burst coherent noise in seismic data is provided comprising (a) comparing a threshold amplitude characteristic acceptance value for a time window of a reference trace to an amplitude characteristic of a test trace of a set of traces within the window and; (b) applying a non-zero scalar to the test trace in the time window if an amplitude of the test trace within the time window is not within the threshold amplitude characteristic acceptance value.

Abstract: In ocean bottom seismic exploration, it is common for co-located hydrophones and geophones to be deployed on the ocean bottom. One problem encountered is the water column reverberation. An improved method and device is proposed for attenuating water column reverberations using co-located hydrophones and geophones in ocean bottom seismic processing. In this method, each recorded hydrophone and geophone signal, or trace, is decomposed into a series of narrow band-pass filtered traces. For each of the filtered traces, a measurement of the energy level is made upon which normalization factors are computed and applied. The resulting filtered, normalized traces are summed. Optionally, prior to application, the normalization factors can be organized by common shot, common group, common offset, and surface consistent normalization factors derived and applied for each pass-band.

Abstract: A method and system are provided for use in marine seismic data surveys to increase fold and offset without increasing streamer length or drag on the streamer boat. Generally the method comprises the use of a second source boat positioned in the steamer path and firing the second source at a time before the recording of information from the first source is finished. By positioning the second source about one streamer length in front of the closest hydrophone, the fold is increased by two for the same length streamer.

Abstract: Acoustic transmitter in particular for use in offshore seismic explorations, having sound-emitting surfaces (1, 2) being adapted to be subjected to vibrational movement by means of a drive unit (21) through at least one push element (22A, 22B) and two plate-like end pieces (3, 4) which are connected to the sound-emitting surfaces. The sound-emitting surfaces are formed by two curved plate members (1, 2) being of comparable width and heigth dimensions. The end pieces (3, 4) have a generally rectangular shape with a first pair of opposing side edges connected (5, 6, 7, 8) to end portions of the plate members (1, 2). Another pair of side edges on each end piece (3, 4) as well as side edges of the plate members engage two side plates (9, 10) which at either side closes the acoustic transmitter, preferably in a tightly enclosing manner.