Institut Francais Du Pe'trole

Compagnie Generale De Geophysique

Institut Francais Du Petrole, Des Carburants Et Lubrifiants Et

Other

Compagnie General De Geophysique

Claude Beauducel

Jacques Cretin

Pierre Gonzalez

Thierry Lepage

Pierre Fouquet

Thierry Gautier

Didier Frot

Jean A Rudaz

Francois Anceau

Pierre Courboulay

Etienne Bolze

Jean Laurent

Patrick Meynier

Philippe J Staron

Michel Constant

Gabriel Ringot

Francedillaois Heslot

Patrick Coquerel

Georges Constantinou

Axelle Baroni

Damien Gille

Daniel Saussier

Francois Couillard

Andre Buisson

Yohan Bentolila

Abdelaziz Faraj

Alain Ausset

Method for determining the composition of a homogeneous fluid, for example a petroleum effluent on flow, an emulsion consisting of water and oil, or a foam consisting of oil and gas. The attenuation and the phase shift of microwave beams that have traversed a fluid of unknown composition with paths of different lengths are measured (stage A). Two equations approaching the measured values are determined, the first equation giving a relation between the attenuation and the length of the path, the second equation giving a relation between the phase shift and the length of the path (stage C). Then the composition of the fluid is determined by comparing the two equations with pairs of equations stored in form of databases, each pair of equations corresponding to a fluid of known composition (stage D).

Method for determining the composition of a fluid

A process and device for measuring the velocity of flow of a fluid stream by measuring the difference between the respective traveltimes of acoustic pulses emitted by means of a generator (G) respectively between two points (P , P ) spaced out along the fluid stream, according to whether they are propagated upstream or downstream in relation to the direction of flow, a difference that is indicative of the displacement velocity of the fluid stream. Measurement of this traveltime difference comprises using an acquisition unit (A) coupled to a processing unit (P) allowing determination of the frequency spectrum of each pulse and measurement of the phase lag affecting at least part of the frequency spectrum of each pulse, resulting from the traveltime thereof. Measurement of the velocity of flow of the fluid stream and of the resulting flow rate is very accurate. The process can be applied in chemical industries, chromatography, etc.

Process and device for measuring the velocity of flow of a fluid stream

Very low distortion hydrophone comprising at least one pair of sensitive elements ( and ) of piezoelectric type (for example and not limitatively), associated with at least one of the opposite flexible faces of a housing ( ) formed by assembling cups ( and ) with rigid edges. The opposite faces of one of the discs, ( ), are provided with electrodes over the total surface thereof. On the other hand, at least one of electrodes ( and ) associated with the opposite faces of second disc ( ) only covers one or more portions (an annular strip for example) of each of these faces in an external zone of each cup ( ) more subjected to nonlinear stresses. Electrodes ( and ) of the two sensitive discs ( and ) are interconnected so as to make the difference between the electric signals generated by the two discs in response to the pressures applied, with the effect, experimentally verified, that the distortion resulting from this layout, notably due to a second harmonic ( ), is practically suppressed. The hydrophone can be used for geophysics, detection or locating, etc.

Low distortion ratio hydrophone

The invention is an interferential refractometry method and device using fine measurement of the displacement of the fringes of an interference pattern between two light beams with one of the beams undergoing phase variations due to variations in the refractive index thereof. The method comprises application, to one of the two beams, of a relatively fast periodic phase modulation by a modulating signal. Displacement of the fringes resulting from the combined application of the two modulations is picked up by a photodetector and a measuring system evaluates the slow modulation by determining the frequency spectrum of the signal coming from the detect or and measuring the phase shift affecting the fundamental frequency of this frequency spectrum. The method may be applied to detection of variations in the composition of mixtures, for example in analytical or preparative chromatography.

Polarized interferential measurement wherein the modulation signal is adjusted to be equal to the duration of the measurement window

In order to restore a clock signal that has been used for coding digitized signals transmitted on a transmission channel, such as a line, the case when the received signals are distorted, the times (ti) when the signals go through their maxima (M) are detected with precision through an analysis of a series of samples (Ep) taken from the signals received during a time 'window' (W) positioned with reference to a local clock. A device determines the amplitude differences between the successive samples and compares the difference configuration as obtained with predetermined standard configurations representative of forms that are acceptable for the maxima. In case when the difference configuration corresponds to no recognized standard configuration, the frequency of the local clock is changed so as to re-establish a sufficient similarity with a standard configuration.

Method and device for regenerating by maxima detection, a clock signal

In a pipe containing a fluid wherein particles circulate, at least one detector is attached. The detector includes a cavity in fluid communication with the pipe by a vent whose section, at least at an opening for fluid communication with a pipe is of the same dimensions as that of the circulating particles. A periodic exciter such as a source of acoustical waves or a generator of the periodic motion piston type suitable for inducing alternate pressure variations in the fluid in the cavity is coupled with the cavity. The excitation frequency can be selected in keeping with a resonance frequency of the cavity. Signals representative of the pressure variations of the excited fluid, resulting from flowing of the particles past the opening of each vent are measured. Processing of the signals allows the velocity of the particles to be determined. Other parameters of the particles can be determined by means of two distinct detectors coupled with the pipe. The detector may be used for monitoring the flow of catalytic particles in continuous reforming plants, for example.

Process and device for monitoring by periodic excitation a flow of

The present invention relates to a method and to a device for testing a partly conductive medium to determine a characteristic thereof. A signal generator generates a periodic excitation signal in a resonant circuit, including a coil which produces a magnetic field, which is coupled to the partially conductive medium. Eddy currents induced in the partially conductive medium cause the current flowing in the resonant circuit to vary. The amplitude of the envelope of the current flowing in the resonant circuit is measured and processed to determine the characteristic of the medium.

Device and method for characterizing a medium comprising at least a

The mobile seismic system according to the invention is made up by interconnecting reception sections (T1) and of anchoring sections (T2), and possibly emission sections, the assembly being suspended in the well by means of an electro-carrying cable (3). The first sections (T1), which are filled with liquid, are delimited at least partly by a wall transparent to acoustic waves. They contain each one or several hydrophones and an electronic module of acquisition of the signals picked up. The second sections (T2) comprise a body provided with retractable anchoring means (13) and with motor means, either autonomous, or connected, by a hydraulic line running along the reception system, to common motor means located preferably in a lower section so as to be used as a ballast weight. The reception system may be continuous or made up of several parts connected to each other by electric or electro-hydraulic linking means. The system is suitable for seismic prospecting in wells for example.

Mobile seismic system of great length for wells

Process and apparatus for performing differential refractive index

A device for simplifying transmission of analog signals received from sensors to a remote station in accordance with the invention includes at least one local electronic module including in combination a modulator for oversampling each analog signal and converting each oversampled analog signal into lower resolution digital words and a transmitter for transmitting the lower resolution words as a bit stream on at least one first transmission channel; at least one synchronization element producing a clock signal allowing synchronization of each modulator with the remote station; and at least one reception module in the remote station including a receiver for receiving the transmitted lower resolution words as a bit stream and a digital filter, coupled to the receiver, for converting each received bit stream received into digital words of a higher resolution (typically 16 or 24 bit words. The invention is useful for transmission of seismic data.

Process and device for the digitized transmission of signals

In order to measure for example the velocity of particles moving within various pipes or enclosures (1), such as catalyst balls circulating in continuous reforming plants, a channel (2) with a section suited to that of the particles, connected to a source of fluid of determined flow rate (4), opens therein and the pressure variations in this channel, resulting from the flow of the particles circulating past the end thereof, which modify the free flowing of the fluid towards the pipe, are measured. The particle velocity is notably determined through an auto-correlation of the signal translating the pressure variations by means of a processing system (6). Two fluid-fed channels (7, 8) may also open onto two different locations along the pipe and, through a crosscorrelation of the signals translating respectively the pressure variations, the velocity and the section of the circulating particles may for example be determined.

Process and device for controlling a flow of particles in a pipe

Monitoring of an underground effluent deposit (2) and the exploration thereof are performed by installing various devices or user modules : reception arrays (Ri, Rj, Rk) such as geophones or hydrophones, condition sensors (C1, C2) , tools requiring electric power supply, etc, in various locations along one or several wells (1) drilled down into a formation, behind well casings or in the annular space between these casings and tubings, and by connecting these devices to a surface station (4), by means of a particularly simple and reliable multi-channel transmission unit. The surface station adapts the commands thereof according to the device to be controlled in return, of receiving all the signals they transmit whether analog or digital and coded, and adapts to several modes of allocation of the transmission channels. With such a system, long-duration monitoring operations may be carried out on a large scale under satisfactory economic conditions.

Stationary system for the active and/or passive monitoring of an

A process for optimizing the transmission rates of digitized signals on transmission lines in multifunction cables, such as logging cables linking well tools to surface installations. The process includes digitising of the data to be transmitted and coding thereof through voltages selected from a set of multilevel coding voltages (2 to 32 for example), and widening towards high frequencies of the passband of each transmission line used, by combination with correcting circuits selected so that the transfer function of the corrected line is substantially that of a filter of the Bessel type, at least in a given frequency range on either side of a 3-dB cut-off frequency fc which depends on the number of coding voltages and on the amplification parameters. Using this process makes it possible to exceed very easily a total flow rate higher than one Mbits/s without increasing the transmission error rate.

Process and device for optimizing signal transmission rates on

Modular device for the reception, the acquisition and the transmission, to a central control and recording unit, of signals picked up by a very large number of seismic acoustic receivers distributed along a streamer of great length under water in operation. The receivers in each one of the sections (Tk) of the streamer are arranged in several groups and the receivers (H1 to Hp) of a same group are connected with an acquisition unit (U1 to Um) located close to them. All the units of each section are connected through digitized command and data transmission lines (LOC,BD) with a common memory and a transmission management unit in an interconnection box (Bk) at one end of the streamer section. Transferring a great part of the electronic equipment into the streamer sections is very favorable for the balancing of the streamer in the water, for obtaining a good signal to noise ratio and it facilitates the development and the exploitation of the material.

Modular device for reception, the acquisition and the transmission of

A reception system including a central core (5) formed of a traction cable (6) and a harness (7) of conducting wires. A fibrous or porous acoustic screen (8) made, for example, from a fibrous or porous material is formed around the core. Sensitive elements are arranged outside this screen, with discontinuous inner electrodes (9) connected to the different wires of the central harness (7), and a common outer electrode (13). A pipe made of a piezoelectric material (12) is formed therebetween. The whole is covered with a protective sheath (2). With such a multi-layered sensitive structure, the manufacturing process of the reception system can be simplified.

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Henonville, France

Claude Beauducel