Schlumberger Technology Corporation

Marine Advanced Research, Inc.

Electromagnetic Instruments, Inc.

Other

Westerngeco L.l.p.

Ugo Conti

Edward Nichols

David Lee Alumbaugh

Andrea Zerilli

Dzevat Omeragic

Leendert Combee

Martin N Howlid

Kevin Eyl

Mark Gundersen

Inflatable hull configuration and connection for a multihull vessel. The inflatable hulls have a longitudinal structural member fastened to the top of the inflatable hulls, with a central body of the multihull vessel supported on the longitudinal structural members by forward and stern legs. The forward legs support the forward part of the central body through a ball joint that allows the forward legs to rotate as a unit relative to the central body, and have their lower ends attached to the forward part of the longitudinal members, each through a spring supported ball joint. The stern legs are each rigidly coupled to the central body, with their lower ends connected to the aft part of the longitudinal members to allow rotation about a vertical axis and a transverse axis, but not the longitudinal axis. A detailed embodiment is disclosed.

Inflatable hull configuration and connection for a multihull vessel

A multi-component field source for surveying subsea formations includes at least two electrodes having a direction of motion, wherein the at least two electrodes are configured to produce an electric dipole in an orientation that is not parallel to both the direction of motion of the electrodes and the seafloor. A method for logging subsea formations includes transmitting electromagnetic energy into the subsea formations with at least two electrodes having a direction of motion and configured to produce an electric dipole in an orientation that is not parallel to both the direction of motion of the electrodes and the seafloor; and receiving signals that comprise electromagnetic energy that has traversed the subsea formations.

Multi-component field sources for subsea exploration

Ocean-going vessels having a load carrying module supported from a pair of spaced apart hulls by legs. The legs may be articulated in two places to provide control of the spacing of the two hulls and to control the elevation of the module off the water. Dynamic control of the articulation may control the response of the vessel, such as to sea conditions. The legs may include aerodynamic surfaces, fixed or controllable, that may be used to aide buoyancy and/or enhance stability, such as by assuring the bow of the hulls does not rise excessively. The hulls preferably are at least partially inflatable, with techniques for installing flexible fuel tanks within a preexisting inflatable hull being disclosed. Also disclosed are modular pressure control systems for controlling pressures in inflatable hulls having a multiplicity of separate inflatable compartments.

Ocean-going vessels

An electrode array for electric and magnetic measurements in a marine environment includes a first set of electrodes connected to a first cable, wherein the first set of electrodes and the first cable are configured to sink to a sea floor in the marine environment; a second set of electrodes connected to a second cable, wherein the second set of electrodes and the second cable are connected to the first cable and configured to float in the marine environment such that the second set of electrodes and the second cable maintain a distance from the sea floor when the first cable sits on the sea floor, and an instrument package connected to the first cable and the second cable, wherein the instrument package is configured to receive voltage signals measured by the first set of electrodes and the second set of electrodes.

Electrode array for marine electric and magnetic field measurements having first and second sets of electrodes connected to respective first and second cables

A marine measurement system is disclosed for obtaining measurements in an underwater operating environment. The system includes a base structure having a top surface, a bottom surface, and cavities provided therebetween. The cavities are also open to the top surface. The measurement system further includes measurement equipment (e.g., electronic equipment and/or instrumentation), which are retained in the cavities. A diaphragm membrane is applied adjacent the top surface and seals the cavities. The diaphragm member is positioned in pressure communication with the operating environment. Furthermore, the cavities are defined by the membrane and the base structure and filled with a pressure compensating fluid that is in pressure communication with the operating environment through the diaphragm membrane.

Remotely operable measurement system and method employing same

A method is provided for conducting an electromagnetic induction survey of a geological formation penetrated by a borehole lined with a conductive casing. The method includes positioning a transmitter in the borehole, whereby the transmitter generates a transmitter magnetic moment, and positioning a distant receiver external of the borehole to detect a magnetic field induced by the transmitter, whereby the distant receiver is disposed across part of the formation from the borehole. Furthermore, an auxiliary receiver is positioned in the borehole proximate the transmitter to detect a magnetic field induced by the transmitter and attenuated by the conductive casing. Subsequently, a first casing attenuation factor that is applicable to the magnetic field measured by the auxiliary receiver is determined from a ratio of the measured magnetic field at the auxiliary receiver and the transmitter magnetic moment. A second casing attenuation factor applicable to the measurement of the magnetic field at the distant receiver is determined from a non-linear relationship (e.g., a power law relationship) between the first casing attenuation factor and the second attenuation factor, wherein the second attenuation factor is less than the first attenuation factor. Then, a formation attenuation factor applicable to the measured magnetic field at the distant receiver is determined from a relationship between the magnetic moment of the transmitter, the second casing attenuation factor, and the measured magnetic field at the distant receiver. Finally, the method correlates the determined value of the formation attenuation factor to a resistivity characteristic of the formation between the distant receiver and the transmitter.

System, apparatus, and method for conducting electromagnetic induction surveys

The vessel has a pair of flexible hulls flexibly coupled to a 'cabin' between and above the hulls, thereby allowing the hulls to independently follow the surface of the water. Motor pods are hinged to the back of the hulls to maintain the propulsion system in the water, even if the stern of one or both hulls tends to lift out of the water when crossing swells and the like. Various other embodiments and features are disclosed.

Flexible ocean-going vessels with surface conforming hulls

A sea-floor electromagnetic measurement device for obtaining underwater measurements of earth formations including a central structure and arms attached to the central structure so that they can pivot relative to the central structure. An electrode is attached to the end of each of the arms or to the central structure, and/or magnetometers are attached to the arms. A method for undertaking sea-floor electromagnetic measurements of earth formations including measuring electric fields at a selected distance from a central structure of an electromagnetic measurement system. Magnetic fields are then measured at the same location.

Marine electromagnetic measurement system

An electromagnetic tomography system for determining properties of geological formation penetrated by at least one borehole lined with a conductive tubular includes a transmitter disposed in a first borehole and adapted to induce a magnetic field, a first receiver disposed in the first borehole and adapted to detect a magnetic field induced in the conductive tubular by the transmitter, and a second receiver adapted to detect a magnetic field induced in the geological formation by the transmitter. A method for determining a conductive tubular correction constant includes generating a magnetic field inside a representative piece of the conductive tubular, determining a first magnetic field amplitude inside the representative piece of the conductive tubular at a location proximate to a position of the generating a magnetic field, determining a second magnetic field amplitude outside the representative piece of the conductive tubular, and deriving the conductive tubular correction constant from a ratio of the first magnetic field amplitude and the second magnetic field amplitude.

Method and apparatus for measuring characteristics of geological formations

A magnetic receiver with a magnetically permeable core is positioned inside a wellbore casing and operated in a feedback mode to reduce attenuation of a measurable magnetic field. The receiver employs a feedback device to reduce mutual coupling between the core and the casing, which reduces the otherwise normal attenuation of em signals inside the casing. The feedback device may be provided in the form of an extra or feedback winding that effectively cancels the inducing field inside the core and reduces the attenuation otherwise caused by the core-casing interaction. Alternatively, the magnetic receiver may employ, as the feedback device, a current feedback amplifier circuit to cancel the inducing field inside the core. Specifically, the circuit is operated to produce a secondary magnetic field that essentially cancels the inducing field inside the core.

Sensor for detecting the magnetic field in the area of downhole casing

An antenna, and method for forming the same, is provided that receives or transmits three (3) components of low frequency magnetic fields while having physical dimensions that can be easily housed inside a slim borehole tool. The antenna includes a permeable core and a plurality of sets of windings of conductive wire surrounding the permeable core, with each set of plurality of sets having a cross-sectional area associated therewith, with the cross-sectionals of the remaining sets. Typically, the cross-sectional area of each of the plurality of cross-sectional areas extends orthogonally to the cross-sectional areas of the remaining cross-sectional areas of the plurality of cross-sectional areas.

Component field antenna for induction borehole logging

A borehole magnetic sensor includes a plurality of primary detector coils, aligned along parallel axes, and connected in series with each other. A corresponding plurality of feedback coils, each associated with a respective detector coil, are arranged to cooperate with an amplifier system to provide negative feedback and null the magnetic field through the detector coils. The feedback coils are connected in parallel.

Multiple-coil magnetic field sensor with series-connected main coils and

A whistle synthesizer comprises a microphone, a housing, system electronics within the housing, and controls outside the housing. The player whistles into the microphone, the signals from which are processed to provide an instrument output signal suitable for communication to an external amplifier. The controls are located within easy reach of the player so that they may be manipulated all the while the player is whistling.

Growing community of inventors

El Cerrito, CA, United States of America

Ugo Conti