47 results about "Apparent conductivity" patented technology

A logging tool is disclosed having transmitting and receiving antennas to measure formation anisotropy. The antennas may preferably be combinations of toroidal, horizontal electric dipole, and horizontal magnetic dipole antennas. In one embodiment, the tool: (a) induces a current flow in the tubing or drill string traversing the formation in a borehole; (b) measures a signal difference between two receiver antennas on the drill string; (c) determines an apparent conductivity of the formation from the resistive component of the signal difference; and (d) uses the apparent conductivity to calculate an anisotropy coefficient with a knowledge of the horizontal conductivity. The tool may further determine a second apparent conductivity of the formation from the reactive component of the signal difference, and use both apparent conductivities to calculate the anisotropy coefficient and the horizontal conductivity. The vertical conductivity can also be determined from these two calculated values in the usual manner.

A method and a system are provided for allowing determination of a distance from a tool to anomaly ahead of the tool. The apparatus for performing the method includes at least one transmitter and at least one receiver. An embodiment of the method includes transmitting electromagnetic signals from the at least one transmitter through the formation surrounding the wellbore and detecting voltage responses at the at least one receiver induced by the electromagnetic signals. The method includes calculating apparent conductivity or apparent resistivity based on a voltage response. The conductivity or resistivity is monitored over time, and the distance to the anomaly is determined from the apparent conductivity or apparent resistivity values.

The invention relates to a nano-nickel oxide / graphene composite material and a preparation method thereof. The composite material is characterized in that: nickel oxide nano-particles uniformly grow on two sides of single-layer graphene to form a novel quasi-two-dimensional composite nano-material. The graphene serving as a substrate frame has good conductivity, and excellent conductivity among the nickel oxide particles is realized through the graphene substrate, so that the apparent electric conductivity of the composite material is improved. The sizes of the nickel oxide nano-particles growing on the graphane flake are between 1 and 10 nanometers; the plane size of the composite graphene nano-flake is between 0.1 and 100 microns, and the thickness of the composite graphene nano-flake is between 1 and 20 nanometers; and the weight percentage of the nickel oxide in the composite material is between 60 and 95 percent. The preparation method comprises two typical steps of: preparing a nano-nickel oxide / graphene precursor material by adopting a chemical solution method; and sintering to form a phase at high temperature in protection of an inert gas. The nano-nickel oxide / graphene composite material prepared by the method has high single electrode capacitance and good circulating performance, and is suitable for electrode materials of super capacitors.

The invention discloses a method for manufacturing substrates of three-dimensional graphene-nickel oxide composite materials. Non-ionic surfactants are used as structure-directing agents, water-soluble A-stage phenolic resin with a low molecular weight is used as a carbon source, foam nickel is used as a mold plate, and the three-dimensional graphene-nickel oxide composite materials can be manufactured by the hydrothermal reaction and high-temperature heat treatment combined method. The hydrothermal reaction temperature ranges from 120 DEG C to 140 DEG C, and the reaction lasts for 18 hours to 24 hours. A high-temperature heat treatment procedure includes raising the temperature at a rate ranging from 1 DEG C / min to 2 DEG C / min under the protection effect of nitrogen or inert gas until the temperature ranges from 300 DEG C to 400 DEG C, keeping the heat for 2 hours to 3 hours, raising the temperature at a rate ranging from 1 DEG C / min to 2 DEG C again until the temperature ranges from 700 DEG C to 900 DEG C, and keeping the heat for 1 hour to 2 hours. The method has the advantages that operation is easy, the apparent conductivity of nickel oxide materials can be effectively improved by the obtained three-dimensional support type graphene-nickel oxide composite materials, the substrates for three-dimensionally growing the materials can be provided, and the method has a wide application prospect in the field of electrode materials of supercapacitors.

The invention relates to a graphene load flower manganese dioxide (MnO2) composite material and an ultrasonic synthetic method thereof. The graphene load flower MnO2 composite material is characterized in that flower MnO2 is composite with graphene layers, and the flower MnO2 is composed of a plurality of flakes which are mutually assembled. Graphene is used as a matrix skeleton and has favorable conductibility, and the flower MnO2 can have favorable conductibility through the graphene layers, thereby increasing the apparent conductivity of the composite material. The diameter of the flower MnO2 growing on both sides of the graphene is from 100 to 300 nm, and the thickness of each flake is from 1 to 10 nm. The material is prepared by the following two typical steps of preparing pyrolytic graphene and ultrasonically synthesizing the graphene load flower MnO2 composite material. The graphene load flower MnO2 composite material prepared by using the ultrasonic synthetic method has the advantages of simple process, high electrode capacitance and good cycle performance and is suitable for electrode materials of super capacitors.

The invention relates to a graphene-loaded lamellar cupric oxide composite material and a hydro-thermal synthesis method thereof. The composite material is characterized in that a CuO (cupric oxide) laminar and a graphene laminar are compounded, and adopts a quasi-two dimensional nano-structure. Graphene serving as a matrix skeleton has excellent conductibility, and the CuO laminar can achieve excellent conductibility through the graphene laminar, so that the apparent electric conductivity of the composite material is improved. The lamellar cupric oxide growing on two sides of the graphene is about 200 nm in width and 300 to 500 nm in length; and a composite graphene nanosheet is 1 to 100 microns in plan view size and 1 to 20 nm in thickness. The composite material is prepared through the following two typical steps: preparing pyrolysis graphene; and obtaining the graphene-loaded lamellar cupric oxide composite material through hydro-thermal synthesis. A single electrode made of the graphene-loaded lamellar cupric oxide composite material prepared by the method is high in capacitance and good in cycling performance. Therefore, the graphene-loaded lamellar cupric oxide composite material is suitable for electrode materials of super capacitors.

A method for providing an image of a formation surrounding a wellbore, includes: obtaining an apparent conductivity curve from main components of resistivity measurements of the formation; performing fitting for cross-components of the resistivity measurements; calculating scaling factors from the cross-component data; scaling apparent conductivity data by the calculated scaling factors; and plotting the scaled conductivity data to provide the image of the anisotropic formation. A system and a computer program product are disclosed.

The invention discloses a time domain aero-electromagnetic data inversion method based on conductivity-depth imaging. First, the apparent conductivity and apparent depth of an underground medium are obtained by use of a conductivity-depth imaging method based on a tale look-up method; then, an inversion initial model is built based on the apparent conductivity and the apparent depth; and finally, inversion is performed by use of a damping characteristic parameter method to complete combination analysis of time domain aero-electromagnetic data. The problem that it is difficult to choose an inversion initial model is solved. As inversion is performed on the basis of the result of approximate imaging, the inversion method has certain constraints of the inversion result, and inversion is of high convergence rate and imaging precision. The invention provides a quick and stable inversion method for time domain aero-electromagnetic data interpretation.

A method and a system are provided for allowing determination of a distance from a tool to anomaly ahead of the tool. The apparatus for performing the method includes at least one transmitter and at least one receiver. An embodiment of the method includes transmitting electromagnetic signals from the at least one transmitter through the formation surrounding the wellbore and detecting voltage responses at the at least one receiver induced by the electromagnetic signals. The method includes calculating apparent conductivity or apparent resistivity based on a voltage response. The conductivity or resistivity is monitored over time, and the distance to the anomaly is determined from the apparent conductivity or apparent resistivity values.

A system and method of correcting skin effect of conductivity measurements made by electromagnetic induction well logging instruments. A limited number of measurements using different frequencies may be used. The skin effect correction system and method is capable of processing a complex signal waveform but only requires the in-phase signal measurements which are then corrected for the skin effect value and the geometric factors of the apparent conductivity measurements, thus making the corrected measurements suitable for advanced processing with modern array-type induction logging tools.

The invention provides a tensor apparent conductivity measurement method. The tensor apparent conductivity measurement method comprises the following steps that 1, an orthogonal electric field E and a curl M of a magnetic field are simultaneously measured on the surface of ground or underground; 2, the tensor apparent conductivity is calculated according to observation data through a formula (please see the formula in the specification), wherein E and M represents observation matrices containing multiple sets of the E and the M. According to the tensor apparent conductivity measurement method, a measured electromagnetic field can adopt a natural electromagnetic field, and also can adopt an electromagnetic field generated through motivation of an artificial field source; the electromagnetic field can be measured at a frequency domain, changes of the tensor apparent conductivity along with the frequency are obtained, and frequency domain sounding is performed; the electromagnetic field also can be measured at a time domain, changes of the tensor apparent conductivity along with time are obtained, and time domain electromagnetic sounding is performed; the calculation formula does not need to make plane wave hypothesis, is also set up on the condition of a non-plane wave field source and is not limited by the field source conditions; the apparent conductivity calculation formula is simple and does not need iteration or parameters such as a field source position and a sending and receiving distance.

A method to determine one or more borehole corrected formation properties using measurements made using a logging tool disposed in a borehole penetrating an earth formation is disclosed. The measurements are used to determine an apparent conductivity tensor for the formation and, for a set of parameters, a parameter value for each parameter in a subset of the set of parameters. A parameter value for each parameter in the set of parameters not in the subset is provided and a borehole-inclusive modeled conductivity tensor is computed. The apparent conductivity tensor and the borehole-inclusive modeled conductivity tensor are iteratively used to optimize the parameter values, and the optimized parameter values are used to compute an optimized conductivity tensor. A borehole corrected conductivity tensor is computed using the optimized conductivity tensor, and the borehole corrected formation properties are determined using the borehole corrected conductivity tensor and / or the optimized parameter values.

A method of quantifying borehole properties, comprising: injecting an electric current from an outer button and an inner button disposed on an equipotential pad into a subterranean formation surround by the borehole, measuring an apparent conductivity or a scaled current for each button, modeling the measurements at a sequence of standoff locations, and, using an inversion technique to determine at least one of the following borehole properties: mudcake thickness, mudcake resistivity, diameter of invasion, flushed zone resistivity and true formation resistivity.

A system and method of correcting skin effect of conductivity measurements made by electromagnetic induction well logging instruments. A limited number of measurements using different frequencies may be used. The skin effect correction system and method is capable of processing a complex signal waveform but only requires the in-phase signal measurements which are then corrected for the skin effect value and the geometric factors of the apparent conductivity measurements, thus making the corrected measurements suitable for advanced processing with modern array-type induction logging tools.

The invention discloses a calculating method for the apparent conductivity of multi-layer media. Calculating is conducted through a following formula (please see the specifications for the formula), according to the formula, sigma 1 is the upper surrounding rock conductivity, sigma 3 is the lower surrounding rock conductivity, and sigma 2 is the middle formation conductivity; G<infinity> is thefull space propagation effect factor; G<2> is the propagation effect factor of the medium 2; and the G<3> is the propagation effect factor of the medium 3. The apparent conductivity of four layers of geoelectric cross sections is calculated through an electromagnetic wave propagation theory, and the root-mean-square error is lowered by 12-45% compared with an undisturbed formation.

The invention discloses a soil and road surface conductivity measuring system mounted on a UAV. The measuring system acquires a signal and transmits a sine wave signal to the ground by a conductivitysensor suspended from the UAV. After the sine wave signal reaches the ground, feedback is performed to produce a weak secondary signal and a secondary attenuation signal, and attitude information is recorded simultaneously. By means of the attitude information, the position of the conductivity sensor is corrected in order to accurately obtain the position information of the secondary attenuation signal. Finally, the conductivity value of a measured object is calculated by means of the secondary attenuation signal. The soil and road surface conductivity measuring system is clear in structure and is easy to realize. Compared with traditional detection, the soil and road surface conductivity measuring system saves time and labors, greatly increase work efficiency, can operate in areas that workers cannot reach previously (such as contaminated areas and damage areas), can quickly obtain the planar graphs of apparent conductivity and apparent magnetic susceptibility, avoids burying electrodes, and has measurement efficiency much higher than that of a traditional DC method.

The invention relates to a phase calibration method of current measuring for induction logging. The phase calibration method includes that vectors of apparent conductivity under the circumstance that distances between an emitting coil and a receiving coil are different are measured for two times respectively, and current measuring phase errors brought in by a current transformer and a nonlinear element in a current measuring circuit are solved, so that errors brought in by a current measuring link are known accurately and eliminated during calculation. By the phase calibration method, scales and measuring accuracy of an array induction logging instrument are improved.

The invention discloses a deconvolution specific resistance treatment method of a cased well. On the basis of the secondary field difference measured by two adjacent depth points, the relation betweenthe secondary field difference and the apparent conductivity difference and stratum conductivity sequence is derived, a stratum conductivity curve is reduced through the deconvolution method, and a stratum specific resistance curve is reduced in a reciprocal manner. The solving problem of the stratum conductivity curve is solved through difference deconvolution; and under the condition that longitudinal geometrical factor spacing is selected correctly, the stratum conductivity can be completely reduced, and the stratum resolution ratio is increased.

The invention provides a method of calculating stratum true conductivity by using well axis electric field distribution, which is simple and effective. The electric field distribution is generated by a transmitting coil after gradual moving of devices, and apparent conductivity distribution is acquired by a plurality of receiving coils, and requirements under conventional technical conditions are satisfied. The method comprises steps that step 1, electric field intensity distribution is measured along a well axis in a wellbore; every time a well logging device moves to a field point, the corresponding electric field distribution is measured; step 2, the measured electric field intensity distribution is converted into an apparent conductivity function; step 3, the apparent conductivity function is used for wellbore correction; step 4, a correct function value is selected from apparent conductivity function values after the wellbore correction, and the stratum true conductivity is acquired. By adopting the brand new induced electric field well logging method principle, the stratum true conductivity is calculated, and therefore the method is simple, calculation efficiency is high, and accuracy is good.

The invention provides a resistivity processing method based on the geometrical factor of a cased well. A reception waveform difference is obtained by conducting subtraction on waveforms measured at adjacent depths at the same source distance, a secondary field difference of measured formations (areas) at two adjacent depth points is obtained, an apparent conductivity difference is further obtained, and deconvolution is conducted on the apparent conductivity difference and a vertical differential geometrical factor difference; the shape of the geometrical factor difference of the cased well isput forward for the first time, the appropriate geometrical factor difference is found from the waveform difference, reception waveforms at four different source distances (0.275 m, 0.43 m, 0.6 m and0.77 m) are utilized to complete restoration of a formation conductivity curve, and the obtained formation conductivity curve is compared and verified with a real formation conductivity curve; and byobtaining reciprocals of the formation conductivities obtained after the first step, the second step, the third step, the fourth step and the fifth step are executed, the formation resistivity curveis obtained, and then distribution of remaining oil can be evaluated.

The invention provides a method for detecting an underground obstacle by utilizing apparent conductivity and a relative dielectric constant, which comprises the following steps of: measuring the apparent conductivity, delineating a horizontal position, reflecting the relative dielectric constant, determining the burying depth and determining the position of the obstacle, and directly measuring the distribution condition of the apparent conductivity in a work area by utilizing a ground conductivity meter. According to the method, the detection means is simple and rapid, and the apparent conductivity profile can be directly obtained to delineate the horizontal direction distribution condition of underground obstacles. Then, according to the horizontal position, a geological radar survey line is established for detailed exploration, and finally, the three-dimensional distribution condition of the underground obstacles is comprehensively determined in combination with a geological radar profile result. According to the invention, the working efficiency is improved, accurate three-dimensional positioning of underground obstacles is realized, and reliable guarantee is provided for later safety construction.

The invention provides a coal seam internal water-rich property calculation method and device and electronic equipment, and relates to the technical field of coal seam water-rich property, and the method comprises the steps: obtaining a normalized induction voltage value through adoption of a ground transient electromagnetic method; calculating apparent conductivity according to the normalized induction voltage value; acquiring electromagnetic wave field intensity by using a wireless electromagnetic wave perspective method; calculating an attenuation coefficient according to the electromagnetic wave field intensity; calculating and obtaining a coal seam dielectric constant according to the apparent conductivity and the attenuation coefficient; determining the coal seam internal water-richproperty according to the coal seam dielectric constant. The coal seam internal water-rich property calculation method and device and electronic equipment can effectively improve the detection precision of the water-rich property of the coal seam.

The invention discloses a method for joint inversion of a stratigraphic dip on the basis of array induction and anisotropy. Firstly, on the basis of array induction electrical resistivity logging data, computational formulas of apparent conductivity and horizontal conductivity of a double-coil system in an inclined heterogeneous stratum are derived; a relation formula of apparent conductivity andhorizontal conductivity of an ideal potentiometric electrode system in an infinitely thick transverse anisotropic stratum is introduced; an anisotropic parameter calculation model of an target stratumsection is built; and apparent conductivity and horizontal conductivity of the target stratum section are obtained through processing with array induction electrical resistivity logging, a functionalrelational expression is built through the apparent conductivity, the horizontal conductivity and anisotropy, and the method for joint inversion of the stratigraphic dip through array induction and anisotropy is formed. The method is applied in a new well, the stratigraphic dip of the target stratum section is obtained, the stratigraphic dip and electric imaging logging are processed to obtain the stratigraphic dip, data dependency is good, so that the tight sandstone stratigraphic dip is calculated accurately through array induction electrical resistivity logging data, precision is high, andreliable data are provided for looking for a tight gas reservoir trap in the future.

The invention belongs to the field of processing methods for time domain airborne electromagnetic data and discloses a fixed wing airborne electromagnetic data conductivity depth imaging method with system auxiliary parameters. The fixed wing airborne electromagnetic data conductivity depth imaging method comprises the following steps: establishing all time channel data tables at multiple fixed flight heights, fixed swing angles, fixed yaw angles and fixed pitch angles; sequentially extracting data and date tables corresponding to time channels; determining the positions of measured data in the tables, and determining apparent conductivity and all auxiliary parameter values according to a linear interpolation algorithm; if the measured data meet a set threshold, outputting the conductivityand auxiliary parameters; judging whether conductivity query of all time channels is finished or not; and obtaining imaging depth according to a skin effect formula. The algorithm is high in imagingspeed and efficiency, meets the requirements of aviation transient electromagnetic processing on mass data, and lays an important science and technology base for rapid exploration capability of mineral resources in China.

The invention discloses a method and device for detecting the thickness and conductivity of a metal coating on the surface of a metal conductor. The method comprises the following steps: generating astandard curve of normalized apparent conductivity according to the characteristics of different coating thicknesses, conductivities and substrate conductivities; acquiring an experimental curve of the equivalent conductivity according to a relationship between the equivalent conductivity of a specific coated conductor to be measured and the penetration depth of an electromagnetic wave under different excitation source frequencies; and determining parameters of a to-be-measured flat plate, and calculating the conductivity of a metal coating and the conductivity of a thickness substrate metal conductor according to the standard curve and the experimental curve. According to the method, the thickness, the conductivity and the substrate conductivity of the micron-order metal coating can be detected at the same time in a high-precision, rapid and nondestructive manner without prior experimental data, and the method is simple and easy to implement.

The invention discloses a logging system and method for measuring true resistivity of a stratum based on an electric field. The logging system comprises a downhole measurement mechanism and an acquisition data analysis mechanism, the acquisition data analysis mechanism comprises a ground mobile data acquisition mechanism and a data processing module, a wellbore is placed in a logging well excavated to a measurement stratum, the downhole measurement mechanism descends to the measurement formation in the wellbore, the ground mobile data acquisition mechanism is connected to the downhole measurement mechanism through a cable, and a wellhead is equipped with a cable hoisting device, and the downhole measurement mechanism is composed of a measurement coil and an electric field measurement maincontrol system. The method is based on the detection and data processing technology under the condition of the full-space multi-frequency emission and multi-point reception measurement stratum electric field, by obtaining massive electric field data, distribution of electric field intensity measured along a well axis is quickly achieved, the electric field intensity distribution is converted intoan apparent conductivity function, and by adaptively processing the apparent conductivity function, rapid measurement of different radial true stratum resistivity under the high signal-to-noise ratiocondition is achieved.

The invention discloses a diode junction capacitance calculation method. The method comprises the following steps: A1, measuring an apparent capacitance value, an apparent conductivity value, an S11 parameter real part, an S11 parameter imaginary part and voltage-current of a diode; A2, calculating a real part and an imaginary part of diode impedance by using the real part and the imaginary part of the parameter S11; A3, according to the impedance relation between the two equivalent circuits of the diode, obtaining calculation formulas of junction capacitance and series resistance; A4, setting an initial junction conductance value Ginit; A5, substituting the initial junction conductance value into the junction capacitance calculation formula to obtain a current junction capacitance value; A6, substituting the current junction capacitance value and the initial junction conductance value into the series resistance calculation formula to obtain a current series resistance value, obtaining a voltage applied to the junction conductance or the junction capacitor according to a voltage-current relationship, and obtaining a current junction conductance calculation value G' according to a conductance formula; and A7, judging whether the difference value between the Ginit and the G' is smaller than a preset threshold value or not; if so, taking the current junction capacitance value as the final value of the junction capacitance; and if not, making Ginit to be equal to G', and executing the step A5 again.