Abstract:
Méthode d'évaluation quantitative de la tortuosité fluide dans réservoir hétérogène à partir de mesures diagraphique (Gamma Ray, densité globale et les lenteurs des ondes longitudinales et transversales) qui permet l'estimation de la perméabilité et de la taille des pores. Elle apporte une amélioration dans estimation du facteur de résistivité de formation. On procède à l'évaluation de la porosité (phi) à partir de la lenteur des ondes longitudinales, du volume d'argile (Vsh) à partir du Gamma ray et de la porosité effective à partir de phi et Vsh calculés précédemment. On détermine la tortuosité (tau) fluide en utilisant plusieurs paramètres petrophysiques. A la fin, on détermine le module d'incompressibilité de structure (Ks), le facteur de résistivité de formation (F), la saturation en eau de formation (Sw), la fréquence adimensionnelle (X), la perméabilité (KO) et la taille des pores (d).
Abstract:
A water-table detection system (1) has a seismic wave generation unit (2) and a remote detector unit (3). Sledgehammer (4) strikes hammer plate (5) to generate a trigger pulse P which is then output by transmitter (8) and tranmitted to the detector unit (3) for triggering of its operation. Detector unit (3) detects pulse P from unit (2), and electro-magnetic signals produced when the seismic waves from unit (2) interact with a soil-water interface (i.e. the water-table) within the ground for storage and processing.
Abstract:
A device for recording seismoelectric signals comprises at least three channels for receiving the seismoelectric signal in different frequency bands, each of those channels comprising a magnetic antenna (1, 2, 3) and, connected in series with the latter, an amplifier (4, 5, 6) and a flat frequency response former (7, 8, 9) as well as two videomagnetophones (10, 11) to the first of which the output of the lowest frequency receiving channel is connected and to the second of which are connected through an adder (12) the outputs of all the other channels.
Abstract:
An example method for determining borehole acoustics using an electromagnetic sensing apparatus may include positioning a downhole tool within a borehole disposed in a formation. The downhole tool may comprise at least one acoustic source and at least one electromagnetic (EM) sensor. An acoustic wave may be emitted from the at least one acoustic source. The acoustic wave may generate an electrical signal when an EM field is present within the borehole. The electrical signal may be measured with the at least one EM sensor. At least one downhole characteristic may be determined based, at least in part, on the measured electrical signal.
Abstract:
An acoustic source on a logging tool is used to generate acoustic waves in a borehole. Acoustic detectors on the logging tool measure the generated acoustic waves. Electrodes on the logging tool are used to measure the potential resulting from the generated acoustic wave. The output of the hydrophones and the electrodes corresponding to Stoneley wave components of the acoustic wave are processed to provide an estimate of formation permeability, acoustoelectric constant, and a velocity of a propagating second compressional wave in the formation.
Abstract:
A method for subsurface Earth surveying includes acquiring seismic data over a selected region of the Earth's subsurface. Seismoelectric data are acquired over a selected region of the Earth's subsurface. Electroseismic data are also acquired over a selected region of the Earth's subsurface. At least one type of electromagnetic survey data is acquired over a selected region of the Earth's subsurface. Survey volumes of the seismic data, the seismoelectric data, the electroseismic data and the electromagnetic data are matched, and a model of the Earth's subsurface is generated that accounts for all of the seismic data, the seismoelectric data, the electroseismic data and the electromagnetic data.
Abstract:
A method for subsurface Earth surveying includes acquiring seismic data over a selected region of the Earth's subsurface. Seismoelectric data are acquired over a selected region of the Earth's subsurface. Electroseismic data are also acquired over a selected region of the Earth's subsurface. At least one type of electromagnetic survey data is acquired over a selected region of the Earth's subsurface. Survey volumes of the seismic data, the seismoelectric data, the electroseismic data and the electromagnetic data are matched, and a model of the Earth's subsurface is generated that accounts for all of the seismic data, the seismoelectric data, the electroseismic data and the electromagnetic data.
Abstract:
A method for seismic exploration using nonlinear conversions (e.g., item 6, Fig. 10) between electromagnetic and seismic energy. Seismic returns from a source waveform (e.g., item 180, Fig. 7A) are correlated with a reference waveform (item 150, Fig. 5B), with both waveforms designed to minimize both correlation side lobes and interference from linear electroseismic effects. A waveform element (e.g., item 10, Fig 1A) is selected to be sequenced by a binary or similar digital code designed to generate an input sweep with the needed depth penetration and noise suppression. Correlation of the seismic response with the reference waveform in a data processing step mathematically aggregates the seismic response from the input sweep into a single wavelet (e.g., item 160, Fig. 6A). Preferred binary digital codes include prescribed Britains of maximal length shift-register sequences (e.g., item 100, Fig. 3A). Also, an apparatus (items 152-157, Fig. 15) for generating the desired waveforms.
Abstract:
Systems and methods are provided for a magneto- seismic exploration of a subsurface region. An electromagnetic source may transmit time-varying electromagnetic field into the subsurface region, in the presence of a static or time-varying magnetic field, such that a component of the electric field associated with the time-varying electromagnetic field is substantially parallel to an interface between two subsurface formations in the subsurface region, wherein the electric field interacts with the static or time-varying magnetic field and creates a Lorentz force in each of the subsurface formations. One or more seismic receivers may detect a seismic signal generated by a Lorentz force change at the interface between the two subsurface formations. A computer system may be programmed to process and present the detected seismic signal.
Abstract:
An integrated acoustic and induction logging tool enables efficient logging operations and reduces logging siring length. In some of the disclosed embodiments, an integrated acoustic and induction logging tool includes a mandrel compatible witb acoustic logging operations and induction logging operations. The integrated acoustic and induction logging tool also includes an. acoustic logging transducer set and an induction togging coil set, where a plurality of transducers of the acoustic togging transducer set are interspersed among a plurality of coils of the induction logging coil set along the mandrel. A related assembly method includes obtaining a mandrel compatible with acoustic logging and induction logging. The method also includes assembling an acoustic logging transducer set and an induction logging coil set along the mandrel, where a plurality of transducers of the acoustic logging transducer set are interspersed among a plurality of coils of the induction logging coil set along the mandrel.