Abstract: A nuclear magnetic resonance relaxation dispersion method to determine the wettability and other parameters of a fluid in a porous medium such as in an earth formation is provided. The method includes the steps of measuring the spin-lattice relaxation time T1 of the fluid in the porous medium at varying polarizing magnetic field strengths or nuclear Larmor frequencies; and determining whether the values of T1 at varying Larmor frequencies follow a dispersion curve that is characteristic of the parameter of the fluid in the porous medium to be determined.

Abstract: A method is described for selecting an additive for enhanced recovery from a subterranean hydrocarbon reservoir including the steps of using parameters characterizing rock type and surfaces in the reservoir, pore geometry and/or distribution, hydrocarbons and/or other constituent elements identified as being present in the reservoir, using parameters characterizing an injection fluid or fluid mixture to be injected into the reservoir, using parameters characterizing the additive to be added to the injection fluid and its concentration; using the parameters to determine at a first level of molecular dynamic modeling the effect of the additive on the interfacial tension between hydrocarbon and water/brine or an equivalent parameter, using the parameters and results derived from the first level of molecular dynamic modeling to determine at a second coarser level of molecular dynamic modeling wettability effects or an equivalent parameter and using the parameters and results derived from first and second level of

Abstract: Apparatus and methods are described for attenuating noise associated with atmospheric pressure fluctuations in a seismic signal during seismic data acquisition using at least a pair of sensors comprising a seismic sensor and a pressure sensor for concurrently receiving a seismic signal and a pressure signal respectively, the sensors being adapted individually to transmit the respective seismic and pressure signals to a remote recording station which is adapted to record a plurality of seismic and pressure signals; and a filter for removing, at least partly, noise associated with atmospheric pressure fluctuations in the seismic signal, the filter employing an input signal from the pressure sensor; and a model of the coupling between the atmosphere and the ground to generate a reference signal which is combined with the seismic signal to produce an output signal.

Abstract: The invention concerns a method for determining the position, in a formation (1) containing at least one electrolytic liquid, of an interface (6) in relation to a bore hole (2). One stimulates at a first instant the interface (6) with an excitation signal, one detects at a second instant (t2) a response signal converted by electro-osmosis or electrokinetic coupling effect and, if appropriate, the exication signal after reflection at a third instant (t3). With the three instants and the propagation velocity of the signals, one calculates the distance between the interface (6) and the bore hole (2).

Abstract: A pumping system (13) for oil wells (1) comprises a pump (20) immersed at the bottom of the well (4) and a flow-meter (32) associated with the pump (20), the immersed pump (20) being supplied by an electric supply source (26). The flow-meter (32) is an electromagnetic flow-meter, also electrically supplied by the supply source (26) of the pump.

Abstract: A method for characterizing a formation. The method comprises exciting the formation with an acoustic wave propagating into the formation. A seismo-electromagnetic signal produced by the acoustic wave within the formation is measured. The method further comprises exciting the formation with an electromagnetic exciting field. An electromagneto-seismic signal produced by the electromagnetic exciting field within the formation is measured. The measured seismo-electromagnetic signal and the measured electromagnetic-seismic signal are analyzed to evaluate characterizing parameters of the formation.

Abstract: An apparatus for determining fluid-pressure diffusivity in a borehole (12) in a formation (10) includes an electrode (16) and a strain measuring device (18),(20) (or a particle velocity measuring device (18),(20) or a particle acceleration measuring device (18),(20)) disposed a fixed distance from the electrode (16). The electrode (16) injects an electrical current into a point on a wall of the borehole (12). The strain measuring device (18),(20) measures strain (or the particle velocity measuring device (18),(20) measuresd particle velocity or the particle acceleration measuring device (18),(20) measures particle acceleration) at the fixed distance from the point of injection of the electrical current over time. The fluid-pressure diffusivity is determined based on the measured strain (or measured particle velocity or measured particle acceleration) over time.

Abstract: A porous geological formation contains electrolytic fluid. During the geophysical prospecting of the formation, a region of interest of the formation where the electrolytic fluid is found is stimulated with an excitation signal. The excitation signal corresponds to an energy of a first type. The excitation signal is converted in the region of interest into a response signal. The response signal corresponds to an energy of a second type. The response signal is detected. An electric polarisation is applied to the region of interest so as to strengthen the response signal relative to what it would be in the absence of polarisation. The electric polarisation comes about by means of a continuous or quasi-continuous polarising electric field. The polarising electric field is modulated in frequency with a frequency which is low relatively to the excitation frequency.

Abstract: An apparatus for determining fluid-pressure diffusivity in a borehole (12) in a formation (10) includes an electrode (16) and a strain measuring device (18),(20) (or a particle velocity measuring device (18),(20) or a particle acceleration measuring device (18),(20)) disposed a fixed distance from the electrode (16). The electrode (16) injects an electrical current into a point on a wall of the borehole (12). The strain measuring device (18),(20) measures strain (or the particle velocity measuring device (18),(20) measuresd particle velocity or the particle acceleration measuring device (18),(20) measures particle acceleration) at the fixed distance from the point of injection of the electrical current over time. The fluid-pressure diffusivity is determined based on the measured strain (or measured particle velocity or measured particle acceleration) over time.

Abstract: The invention concerns a method for determining the position, in a formation (1) containing at least one electrolytic liquid, of an interface (6) in relation to a bore hole (2). One stimulates at a first instant the interface (6) with an excitation signal, one detects at a second instant (t2) a response signal converted by electro-osmosis or electrokinetic coupling effect and, if appropriate, the exication signal after reflection at a third instant (t3). With the three instants and the propagation velocity of the signals, one calculates the distance between the interface (6) and the bore hole (2).

Abstract: A pumping system (13) for oil wells (1) comprises a pump (20) immersed at the bottom of the well (4) and a flow-meter (32) associated with the pump (20), the immersed pump (20) being supplied by an electric supply source (26). The flow-meter (32) is an electromagnetic flow-meter, also electrically supplied by the supply source (26) of the pump.

Abstract: It is a process of geophysical prospecting of a porous geological formation (1) containing at least one electrolytic fluid, comprising the following steps: stimulation of a region of interest (90) of the formation where the electrolytic fluid is found with an excitation signal corresponding to an energy of a first type, in such a way that the excitation signal is converted in the region of interest into a response signal corresponding to an energy of a second type, detection of a response signal, application of an electric polarisation to the region of interest (90) so as to strengthen the response signal relative to what it would be in the absence of polarisation.

Abstract: The invention concerns an ultrasonic fluid counter including at least two ultrasonic transducers collectively defining an ultrasonic measuring path and emitting and receiving ultrasonic waves in the fluid along said ultrasonic measuring path according to at least one ultrasonic frequency, wherein attenuation means for attenuating parasitic ultrasonic waves generated outside said fluid counter and transmitted by the fluid according to the ultrasonic frequency or frequencies are associated with the fluid counter.

Abstract: A fluidic oscillator is symmetrical about a longitudinal plane of symmetry in which a longitudinal fluid flow direction is contained. The oscillator generates a two-dimensional jet of fluid that oscillates transversely relative to said longitudinal plane symmetry. An ultrasound signal is generated in the fluid flow travelling from one transducer towards another. The ultrasound signal is received and modulated by the oscillations of the jet of fluid. The received signal is processed to determine a volume-related quantity concerning the fluid that has flowed through said fluidic oscillator. The tow ultrasound transducers are substantially in alignment with the longitudinal plane of symmetry.

Abstract: To avoid disturbing measurement dephasings due to reflections from walls, the fluid velocity-measurement device comprises a pair of input-output transducers (18 and 20) located inside measurement chamber (16) which has the form of a revolution ellipsoid, each of transducers (18 and 20) being mounted at one of the focal points (F1 and F2) of the ellipsoid.

Abstract: A flow rectifier for mounting in a circular section duct conveying a fluid flow, the rectifier establishing two series of oppositely-rotating vortices in a ring, which vortices cancel one another, and are created by two series of angularly offset fins. The first series of fins is disposed uniformly around the inside surface of the ring while the second series of fins is disposed uniformly around a circumference centered on the center of the ring.