Abstract: Method for survey design including configuring electrodes to reduce near-surface noise in the seismic response from an electroseismic survey of a subterranean formation. Different embodiments of the invention include (1) selective measurement of the surface noise to remove it from the data; (2) suppressing surface noise generation by reducing electric fields in the vicinity of some of the electrodes; (3) creating source signature differences between the near-surface seismic response and the deep response enabling the near surface response to be removed in data processing; (4) applying an external near-surface magnetic field to modulate the near-surface seismic response, enabling it to be removed in processing; and (5) constructing a partial Faraday cage to shield a near-surface region from fields generated by the electrodes.

Abstract: A method for seismic exploration using nonlinear conversions between electromagnetic and seismic energy, with particular attention to the electromagnetic source waveform used. According to the invention, seismic returns from a source waveform are correlated with a reference waveform, with both waveforms custom designed to minimize both correlation side lobes and interference from linear electroseismic effects. A waveform element is selected which may be sequenced by a binary or similar digital code embodying the desired custom design 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. Preferred binary digital codes include prescribed variations of maximal length shift-register sequences. Also, an apparatus for generating the desired waveforms.

Abstract: A method for seismic exploration using nonlinear conversions between electromagnetic and seismic energy, with particular attention to the electromagnetic source waveform used. According to the invention, seismic returns from a source waveform are correlated with a reference waveform, with both waveforms custom designed to minimize both correlation side lobes and interference from linear electroseismic effects. A waveform element is selected which may be sequenced by a binary or similar digital code embodying the desired custom design 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. Preferred binary digital codes include prescribed variations of maximal length shift-register sequences. Also, an apparatus for generating the desired waveforms.

Abstract: A method for seismic exploration using conversions between electromagnetic and seismic energy, with particular attention to the electromagnetic source waveform used. According to the invention, source waveforms are correlated with reference waveforms selected to minimize correlation side lobes. Line power at 60 Hz may be used to provide a waveform element which may be sequenced by a binary code to generate an extended source waveform segment with minimal correlation side lobes. Preferred binary codes include Golay complementary pairs and maximal length shift-register sequences.

Abstract: A method for seismic exploration using conversions between electromagnetic and seismic energy, with particular attention to the electromagnetic source waveform used. According to the invention, source waveforms are correlated with reference waveforms selected to minimize correlation side lobes. Line power at 60 Hz may be used to provide a waveform element which may be sequenced by a binary code to generate an extended source waveform segment with minimal correlation side lobes. Preferred binary codes include Golay complementary pairs and maximal length shift-register sequences.

Abstract: A method and apparatus for estimating the earth's resistance (conductivity) as a function of depth using electroseismic prospecting (ESP) or inverse ESP techniques. Resistance is determined by the frequency-dependent attenuation of reflected EM signals which are produced by application of seismic signals to the earth. A seismic wave is generated by conventional means into the earth, and EM waves are generated back to the surface by different reflectors at different depth levels. This propagation attenuates the high frequencies preferentially. EM waves generated at lower depths are further attenuated relative to those waves generated at more shallow depths. The method and apparatus determines the difference in spectral content between the reflected signals from different horizons based on their relative attenuation and uses this difference as a direct measure of the conductivity between the horizons.

Abstract: A low noise, magnetotelluric, intercalation electrode is disclosed that is both electronically and ionically conductive and stable in ground water brine. The electrode is comprised of an inert or chemically inactive long cylindrical and porous support shield, a semipermeable membrane located in the shield selectively permeable to the positive ions of a metal selected from the group consisting of Na+ and K+ ions, a brine electrolyte, and an electrode axis located in the brine electrolyte that includes an electronically conductive, metallic material ionically reversible to Na+ and K+. The electrode is sealed and attachable at its electrode axis to a wire leading to another electrode spaced apart therefrom. The wire connection permits voltage measurements and thereby provides a method for determining the resistivity between the electrodes at frequencies that are quite low without being interferred with by noise attendant prior art magnetotelluric electrodes.

Abstract: A method of electroseismic prospecting is disclosed for detecting either the presence of two immiscible fluids present in a porous subterranean formation or the presence of a high-permeability rock formation including a substantially aqueous phase therein. A seismic impact produces an acoustical wavefront that results in an enhanced electromagnetic signal when it encounters either types of the above-described formations. This resulting enhanced electromagnetic signal is detectable as an indication of a likely hydrocarbon deposit, thereby giving additional data information with conventional seismic data to the geophysical prospector.

Abstract: A method for determining pore-dependent properties, such as electrical conductivity and absolute permeability, of a porous sample by use of capillary pressure measurements. Capillary pressure data are obtained by performing nonwetting fluid intrusion measurements on a sample. The lowest applied pressure at which the intruding fluid forms a connected path spanning the sample (the "threshold capillary pressure") is determined. The sample's conductivity or absolute permeability, or both, may be determined in a preferred embodiment from the characteristic pore diameter corresponding to the threshold capillary pressure, an other parameters extracted from the measured capillary pressure data. The invention does not require use of any arbitrary, empirically adjustable parameter to predict conductivity or permeability. The method may be performed to characterize small samples of porous rock such as those obtained during borehold drilling operations.

Abstract: A method and apparatus for predicting pore-dependent physical properties of a microporous solid from measurements of the geometric statistical characteristics of the solid. In a preferred embodiment, the method involves a microscopic determination of the number of geometric features of the pore surface as seen by microscopy performed at several levels of magnification. The fractal dimensionality of the pore space and the range of length scales over which the geometric features of the solid obey a self-similar size distribution are determined. From the measured data, such properties as the porosity, electrical conductivity, and permeability are determined. The method may be performed to determine pore-dependent physical properties of various microporous solids, including reservoir rock, heterogeneous catalyst materials, and electrochemical electrodes.

Abstract: A method for measuring the capacity of an electrochemical cell involving the sequential stepping of the voltage applied to the cell and measurement of the accumulated charge. On each voltage step the time dependence of the current passing through the cell is monitored and a step to a new voltage level is made when the current reaches a small but finite value I.sub.minimum, indicating a given level of charges has been attained. The values of the voltage and charge measured at the current level I.sub.minimum may be arbitrarily close to the thermodynamically determined values. Additionally, the time dependent current may be measured while the cell voltage is maintained constant to obtain the kinetic behavior of the battery. Thermodynamically and kinetically related parameters are useful for the performance characterization of electrochemical cells.

Abstract: The present invention is directed to an electric current-producing cell which contains:(a) an anode having as its anode-active material one or more metals selected from a group consisting of Periodic Table Group Ia metals, Group Ib metals, Group IIa metals and Group IIb metals;a cathode, comprising:(i) metalized containment means having a plurality of apertures therein, said apertures having an average cross-sectional dimension of about 1 to about 100 microns; and(ii) cathode-active molybdenum sulfide contained within said metalized containment means; and(c) an electrolyte which is chemically inert with respect to said anode and said cathode and which permits the migration of ions between said anode and said cathode.

Abstract: Metallic titanium and a stoichiometric excess of elemental sulfur are reacted at a temperature above about 630.degree. C. but below the critical temperature of elemental sulfur under superatmospheric pressures sufficiently great to insure the presence of molten elemental sulfur to produce titanium disulfide. Upon completion of the reaction, the titanium disulfide is cooled rapidly from at least about 630.degree. C. to minimize formation of titanium trisulfide and titanium disulfide is then separated from the elemental sulfur.

Abstract: A new composition of matter corresponds to the formula A.sub.x M(PS.sub.3).sub.y wherein A is at least one Group Ia metal, x is a numerical value greater than zero but equal to or less than 6 divided by the valency of the element, M is at least one transition metal selected from the group consisting of nickel or iron, P is phosphorus, S is sulfur and y is a numerical value between about 0.9 and 1.0. These materials are useful as cathode materials in electrochemical cells and as thermal collectors from solar radiation.Compositions of the present invention are used in fabricating rechargeable electrochemical cells in the discharged state which comprise an anode containing as the anode-active material at least one Group Ia metal; a cathode containing as the cathode-active material a non stoichiometric trisulfide of the formula A.sub.x M(PS.sub.3).sub.

Abstract: Finely divided, stoichiometric titanium disulfide is prepared by directly reacting metallic titanium with less than stoichiometric amounts of elemental sulfur at a temperature between about 400.degree. and 1,000.degree.C. to form finely divided, nonstoichiometric, titanium-rich titanium disulfide. The titanium-rich titanium disulfide is then annealed at a temperature between about 400.degree. and about 600.degree.C. in an atmosphere having a sulfur partial pressure approximately equal to the sulfur partial pressure of stoichiometric titanium disulfide whereby the sulfur in the atmosphere reacts with the titanium-rich titanium disulfide to form a finely divided, stoichiometric titanium disulfide.

Abstract: A method for seismic exploration using conversions between electromagnetic and seismic energy, with particular attention to the electromagnetic source waveform used. According to the invention, source waveforms are correlated with reference waveforms selected to minimize correlation side lobes. Line power at 60 Hz may be used to provide a waveform element which may be sequenced by a binary code to generate an extended source waveform segment with minimal correlation side lobes. Preferred binary codes include Golay complementary pairs and maximal length shift-register sequences.

Abstract: A method for seismic exploration using nonlinear conversions between electromagnetic and seismic energy, with particular attention to the electromagnetic source waveform used. According to the invention, seismic returns from a source waveform are correlated with a reference waveform, with both waveforms custom designed to minimize both correlation side lobes and interference from linear electroseismic effects. A waveform element is selected which may be sequenced by a binary or similar digital code embodying the desired custom design 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. Preferred binary digital codes include prescribed variations of maximal length shift-register sequences. Also, an apparatus for generating the desired waveforms.

Abstract: A marine geophysical prospecting system employs a hydrophone streamer cable containing electromagnetic field sensors, modified to be towed at a preselected distance above the sea floor by a first marine vessel senses electromagnetic energy from selected substrata beneath bodies of water. The voltage between sensors may be amplified by amplifiers in the cable or by amplifiers aboard the towing vessel. Optionally, a second similarly modified cable is preferably located above the near-bottom cable. Both cables may also contain hydrophones and/or accelerometers, as well as depth and position sensors. Optionally, a second vessel tows at least one conventional seismic source to create compressional energy which propagates downwardly through the water into the substrata beneath the body of water. At appropriate porous subsurface formations, the acoustic energy is converted to electromagnetic energy.

Abstract: A method of seismic prospecting using electromagnetic grounded antennas to detect electromagnetic waves that are produced from acoustic waves in the earth's formation. Seismic waves reflected by a formation in the earth are converted into electromagnetic waves in the vicinity of the antenna according to the streaming potential theory. The antenna has two electrodes which detect the horizontal component of the electromagnetic waves, thus providing additional seismic information that is not readily available using standard geophones. Antennas are also not subject to coupling problems and thus provide more accurate information than traditional geophones. For example, using multicomponent detection, all three components of the seismic pressure gradient can be detected.