449 results about "Apparent resistivity" patented technology

The invention discloses a roadway drivage drilling induced polarization advance water probing forecasting method, device and probe. The probe is placed in a drill hole; a power supply negative electrode B is mounted in a roadway outside the drill hole and is connected with an on-site main machine by a power supply cable; a power supply positive electrode A, a measuring electrode M and a measuring electrode N of the probe are mounted inside the drill hole, and are connected with the on-site main machine by the power supply cable and a signal cable; the power supply positive electrode A and the power supply negative electrode B outside the drill hole form the power supply cable; the on-site main machine measures an electric field change signal by the measuring electrode M and the measuring electrode N of the probe; and the electric field change signal is input to the main machine to calculate and detect the apparent resistivity and apparent chargeability of a target; the probe is propelled to repeat the steps at each measuring point to measure the apparent resistivity and apparent chargeability of each point and generate a resistivity profile map and a chargeability profile map; and the rate of change of the apparent resistivity and apparent chargeability is calculated to determine an inner geological structure taking a drilling axis as a central cylindrical space.

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 pressure rock failure and instability process and dynamic permeability test apparatus and a method thereof. A stress strain signal, a sound emission signal and an apparent resistivity signal in the pressure rock failure and instability process are acquired and processed by using a large pressure rock permeability test device to obtain the stress strain relationship, the quantity and positions of sound emission events and the rock apparent resistivity change rule induced by pressure water permeability increase in large pressure rock failure and instability process in order to obtain the dynamic evolution role of crack expansion, perforation and instability in the rock failure process under hydraulic-mechanical coupling action and the corresponding dynamic permeability. The hydraulic-mechanical coupling failure mechanism and the pressure permeability of rocks, and the deformation and strength characteristics, the crack expansion, perforation and failure characteristics and the permeability evolution rule of pressure water in the crack expansion-perforation-failure process of the rocks under the hydraulic-mechanical coupling action are researched in the invention. The apparatus and the method have important engineering values in realization of safe mining under water pressure on pressure water.

The invention relates to a novel frequency domain ground-to-air electromagnetic prospecting method which adopts a work mode of land launching and air receiving of electromagnetic waves to extract signal frequency spectrums and gives the underground electrical structure an inverse interpretation through a whole-region apparent resistivity method. A launching system which works on the ground launches multi-frequency pseudo-random waves towards the underground through multiple cascades and the signal with multiple frequencies can be obtained with one triggering, thereby greatly improving the detection efficiency. A receiving system is loaded on an aircraft, so when measuring the magnetic fields in the testing zone, it can adapt to the environment of complex surface structures, reduce the static effect caused by the near field effect and expands the detection range of electromagnetic prospecting. The receiving system can correct and compensate tested magnetic-field components when measuring multiple magnetic-field components, so the resolution capability of magnetic field measurement is improved. The frequency domain ground-to-air electromagnetic prospecting method is applicable to depth detection of severe surface zones and has the advantages of being wide in detection range, large in detection depth, high in detection efficiency, etc.

The invention relates to an electrical source transient electromagnet ground-air detection method. The electrical source transient electromagnet ground-air detection method comprises the steps that a long grounding wire is adopted as an emitting source, and a helicopter or an unmanned aerial vehicle carries a receiving coil for data collection; observation data are processed according to a full-domain apparent resistivity method, qualitative interpretation on deep geological targets is finished, and profile information such as the attitude, extending direction and scale of the geological targets is obtained; ground-air data are interpreted and processed according to a transient electromagnetic wave field transform method, a three-dimensional migration imaging technology and an inverse synthetic aperture method, fine detection of the deep targets is finished, and detailed information such as the depth, shape and electrical structures of the deep geological structure is obtained. The electrical source transient electromagnet ground-air detection method can achieve electromagnetic detection rapidly on a large scale, the deep geological targets can be detected in a detailed mode, and the accurate and detailed geological information of the deep geological targets can be obtained.

The invention discloses a method for positioning an artificial wetland clogging area through a resistivity curve. The method includes the steps that first, a direct-current resistivity symmetrical four-pole sounding device is arranged above an artificial wetland, and the apparent resistivity is measured according to the mode that the electrode spacing becomes bigger and bigger; second, a power supply positive electrode A, a power supply negative electrode B, a measurement electrode M and a measurement electrode N of the direct-current resistivity symmetrical four-pole sounding device are all arranged symmetrical about a measurement point, and the apparent resistivity (please see the formula in the specification) of the electrode spacing is calculated every time the power supply electrode spacing is changed; third, the measured apparent resistivity is subjected to inversion, and the resistivity depth measurement curve is drawn according to the resistivity values obtained through inversion; fourth, the non-clogging area of the artificial wetland has the low resistivity characteristic, the clogging area of the artificial wetland has the high resistivity characteristic, and on the resistivity depth measurement curve, the vertical spatial position of the clogging area in the measurement point is determined according to the changing characteristic of the resistivity value. According to the method, on the basis of the conductivity difference of dielectric, the artificial wetland clogging area can be positioned through the resistivity difference.

The invention discloses a method for positioning a constructed wetland blocked area on the basis of the two-dimensional resistivity imaging technology. The method includes the steps of firstly, conducting a two-dimensional apparent resistivity section survey through the high-intensity resistivity method and three-pole rectangular AMN and MNB devices by reasonably arranging survey lines and setting collection parameters on the premise of the resistivity difference between the blocked packing area and the non-blocked packing area and on the basis of collecting and analyzing existing constructed wetland resources; secondly, conducting two-dimensional inversion on the two three-pole apparent resistivity sections obtained through measurement, converting apparent resistivity data into resistivity data, drawing the contour map of the resistivity sections, and achieving constructed wetland two-dimensional resistivity imaging; thirdly, achieving the aim of positioning the constructed wetland blocked area according to the two-dimensional resistivity imaging characteristics and the resistivity difference analysis. The method is economical and easy to conduct and can fill in the technical gaps in the constructed wetland blocked area two-dimensional positioning, and the powerful technical guarantees are provided for continuous and efficient running of constructed wetlands.

The invention discloses a method for positioning a constructed wetland blocked region through composite profiling apparent resistivity curves. A composite profiling apparent resistivity measuring device is arranged on a constructed wetland and performs measuring point by point in an apparent resistivity profiling mode, a power supply positive electrode A, a power supply positive electrode B, a measuring electrode M and a measuring electrode N of the measuring device are arranged symmetrical about a measuring point O, measuring is performed between A and O by the selection of two electrode distances, and an 'infinitely distant' electrode C is arranged perpendicular to the measuring line. A measured apparent resistivity pAS and a measured apparent resistivity pBS which are obtained according to AO=H/3 and AO=H are used for drawing the composite profiling apparent resistivity curves in a full line and an imagery line respectively. If the measuring line is blocked, the composite profiling apparent resistivity curves will have the characteristic of a high-resistance negative intersection point, and the transverse position of the blocked region can be determined according to the position of the high-resistance negative intersection point; according to the characteristics of the apparent resistivity curves of the two electrode distances, the longitudinal distribution position of the blocked region is roughly judged, and namely the spatial distribution of the blocked region on the measuring line is determined.

The invention relates to a direct current electric method advanced detection method. Influences of adverse factors in a rear area can be effectively avoided, the signal-to-noise ratio and the resolution capacity to anomalous bodies in stratum media on the periphery of a hole are improved, the detection accuracy rate is improved, current electrodes are fixed behind a roadway construction facing head, steady currents are provided for stratums, a point power source field is built, a change rule of the point power source field is observed along the interior of the stratum drilled hole in front of the facing head, and hidden disaster-caused bodies in front of the roadway construction position are detected. The direct current electric method advanced detection method relates to the multiple current electrodes arranged nearby the roadway construction facing head, a power supply system is formed by the current electrodes and an infinite electrode, and a receiving system composed of receiving electrodes is arranged in the drilled hole. The receiving electrodes are sequentially and movably distributed from a hole opening to the deep portion, potential differences generated when the three current electrodes respectively supply power are received when the receiving electrodes move one time, and the apparent resistivity at the corresponding position can be calculated. The potential differences and the calculated apparent resistivity serve as essential data, the three sets of data are jointly processed, and data bodies capable of being used for geological interpretations are obtained.

The invention discloses a directional transient electromagnetic device in a drill hole and a measurement method thereof. A novel well logging system of a special transient electromagnetic detector in the drill hole is formed through combining a transient electromagnetic method with the omnibearing well logging technology. Transient electromagnetic field information of different bearings from random depth is provided for the drill hole, including induced potential and apparent resistivity parameters within a certain range of the hole wall of the drill hole and the interior of the hole wall. Byusing the device, well logging can be performed on the drill hole with a random filling medium. The directional transient electromagnetic device in the drill hole especially adapts to the well logging of dry holes, such as mine gas discharging holes, roadway drift boring drill holes and the like, can be used for performing imaging well logging on a geological occurrence state within the range of the drill hole, and can be used for probing gas geological features around the drill hole, the water-bearing ability of a rock stratum and geological lithology and structures.

The invention discloses a resistivity anisotropy recognition method in a horizontal well stratum environment. Firstly, an azimuth natural GR and an azimuth resistivity logging are obtained through logging, and then a stratigraphic dip and a stratigraphic azimuth angle are extracted. Secondly, the instrument azimuthal resistivity logging response value at multiple spacings and different frequencies in a horizontal well are acquired through logging. Through the environmental correction and automatic layering process, a false layer is removed, and standardized logging data and a stratum layering interface are obtained. Thirdly, according to a stratigraphic dip extracting result, the layering interface, an apparent resistivity measured value and adjoining well data, a horizontal well stratum model is constructed. Finally, the stratum model is subjected to back calculation, and then an anisotropy coefficient and a stratum resistivity inversion result are outputted. According to the method, the real resistivity information and the anisotropy coefficient information of the stratum in the horizontal well environment are extracted based on azimuthal resistivity logging data while drilling, so that the existing logging evaluation data of the horizontal well are perfected. During the comprehensive interpretation and evaluation process of the logging data of the horizontal well, the reservoir oil saturation and the like can be accurately calculated based on the stratum real resistivity and the anisotropy coefficient. As a result, the method provides reliable parameters for reservoir evaluation.

Methods and systems are provided for obtaining both magnetic and apparent resistivity ultra-deep reading electromagnetic measurements at the same time and/or by a single tool. The system can include a magnetometer, a current source electrode, a pair of voltage measuring electrodes, and a current return electrode. Using such a system can enable a lowering a tool into a relief well and obtaining both magnetic and apparent resistivity ultra-deep reading electromagnetic measurements in a single trip in order to provide a more accurate and faster determination of the distance and direction to a cased blown out well in order to shorten the time required to intersect and kill the blown out well.

The invention relates to a sandstone reservoir water layer resistivity-based stratum data processing method, which belongs to a resistivity-based reservoir attribute identification method and is suitable for identifying underground water layers. The method comprises the following steps: acquiring reservoir lithology data by using geological exploration equipment; analyzing the acquired reservoir lithology data with analysis equipment to acquire total sandstone porosity, bound water saturation, stratum water density, stratum crude oil density, movable stratum water resistivity, stratum bound water resistivity, mud and mud filtrate resistivity, true sandstone water layer resistivity, stratum fluid replacement rate and mud filtrate distribution coefficient; and finally, acquiring polluted sandstone water layer apparent resistivity, and judging whether the sandstone reservoir is the water layer by comparing the numerical relationship between the apparent resistivity and true resistivity of the sandstone reservoir depth side direction and the measured resistivity. By analyzing the pollution degree of the sandstone reservoir around a borehole, the method avoids mistakenly jetting the water layer when the hydrocarbon reservoir is put into development and perforation, reduces inaccurate judgment for abnormality, and reduces the development cost.

The invention relates to a data processing method for carrying out static correction on transient electromagnetic data. The method comprises the following steps: ensuring that influences of field electromagnetic interference and a frame effect are eliminated, calculating late period apparent resistivity according to a late period apparent resistivity formula, calculating apparent depth according to an apparent depth empirical formula, selecting a reference point and a correction mode according to measuring point elevation data, determining a static correction factor d through a ratio between each measuring point apparent depth and reference point apparent depth, correcting values of V and t by utilizing relations between the static correction factor d and cube and square of V and t, substituting obtained corrected Vc into the late period apparent resistivity formula to calculate new rho[c], substituting the new rho[c] into the apparent depth empirical formula to obtain corrected apparent depth, and adding reference point elevation to the depth to complete a static correction process. According to the invention, false abnormity generated by landform fluctuation in qualitative interpretation can be rapidly and effectively eliminated, transient electromagnetic method data processing speed and interpretation precision are substantially raised, and large scale development and application of the method technology are promoted.

The invention discloses a magnetic reference processing method for acquiring data in three dimensions through audio-frequency magnetotelluric sounding. The method can be used for acquiring high-quality electromagnetic field data. The method comprises the following steps: three-dimensional observation is conducted; observation points are distributed as a rectangular net on a rugged topography surface; a net observation density is defined according to an exploration proportional scale and the requirement of exploration depth; an electric channel is observed and a magnetic field component value is calculated at each observation point; the Cagniard resistivity corrected by the observation points is calculated by using the magnetic reference data. The magnetic reference processing method can be used for improving the working efficiency, independently collecting magnetic channels and electric channels and acquiring high-quality electromagnetic field data.

The invention discloses an advanced-prediction observation system while drilling, and is characterized in that: a power supply electrode is arranged at the bottom of a bored well; a measurement electrode group is arranged above the power supply electrode in the bored well; a remote reference electrode and the power supply electrode are connected with an electrical instrument respectively via a cable; the measurement electrode group is connected with the electrical instrument via a measurement cable and an electrode conversion switch; and an apparent resistivity calculating unit or an induced polarization amplitude frequency calculating unit is arranged in the electrical instrument. The advanced-prediction observation system while drilling is high in detection accuracy, simple in operationand construction, low in measuring cost, and has good application value.

The invention provides a stratum anisotropy information extracting and correcting method and system. The method comprises the following steps that an array lateral logging response chart and an anisotropy correcting chart are built through a plurality of different stratum models in a simulation way; four apparent resistivity curves of different radial detecting depths are obtained through underground measuring data measured by an underground array lateral logging instrument; the storehouse checking inversion is carried out by adopting the obtained apparent resistivity and the built logging response chart, and the stratum horizontal resistivity and the anisotropy coefficient are extracted; the stratum vertical resistivity is calculated according to the extracted stratum horizontal resistivity and the anisotropy coefficient; the apparent resistivity curves of different radial detecting depths are respectively corrected according to the extracted anisotropy coefficient and the built anisotropy correcting chart, and four corrected apparent resistivity curves are obtained. The method and the system adopting the scheme have the advantages that the complexity of the program design can be reduced, more precise stratum resistivity information is obtained, and the evaluation precision of oil and gas saturability is improved.

The invention provides an electromagnetic data terrain correction method, comprising the following steps: actually measuring electromagnetic data, averaging apparent resistivity and phases, changing a frequency-apparent resistivity relationship into a depth-resistivity relationship, obtaining a model which rises and falls with terrains, carrying out a parallel two-dimensional forward modeling according to frequencies, obtaining a two-dimensional forward modeling apparent resistivity and a two-dimensional forward modeling phase of a stratified model with the terrains, gaining the apparent resistivity of the stratified model, and correcting upward and downward continuations according to a one-dimensional impedance recursion formula of the magneto-telluric field and the relative elevations of measuring points. With the adoption of the stratified model and an upward/downward continuation technique relevant with the terrains, the problem that a mirror-image relationship exists between the apparent resistivity and the terrains and between a phase section and the terrains after the application of the traditional method can be suppressed, so that the effect on terrain correction is modified; and meanwhile, the capability and the processing efficiency of the terrain correction can be improved through the adoption of a parallel processing method for the correction of electromagnetic data.