Abstract: The present disclosure describes a dynamic geo-stationary actuation technique that may be incorporated into a rotary steerable system 200. An example method described herein may include receiving a first angular orientation of a rotating housing 201 disposed in a borehole. The first angular orientation may be received from a sensor assembly 205 coupled to the housing 201, and the housing 201 may be coupled to a drill bit 203. A desired drilling direction for the drill bit 203 may also be received. A first trigger signal to a first actuator 206 coupled to the rotating housing 21 may be generated based, at least in part, on the first angular orientation and the desired drilling direction.

Abstract: A multi-string corrosion monitoring method includes using a first set of electromagnetic (EM) log data to calculate attributes of a first casing string while attributes of a second casing string are assigned a fixed value. The method also includes using a second set of EM log data to calculate attributes of a second casing string while attributes of the first casing string are assigned a fixed value.

Abstract: Disclosed herein are embodiments of systems, methods, and computer program products for evaluating sand-resistivity and/or sand-conductivity, as well as saturation in laminated shale-sand formations with biaxial anisotropy (BA) in resistivity. In one embodiment, the method determines sand resistivity (Rsd) of the laminated shale-sand formation directly from triaxial resistivities (Rx, Ry, and Rz) of the laminated shale-sand formation based on a bimodal model with BA anisotropy. In another embodiment, the method determines sand resistivity (Rsd) directly based on a bimodal model with transverse isotropy (TI) anisotropy using the triaxial resistivities, horizontal resistivity, and vertical resistivity (Rx, Ry, Rz, Rh, and Rv). In another disclosed embodiment, the above methods may be used to perform quality control on a determined sand-resistivity and saturation of a laminated shale-sand formation.

Abstract: Methods are provided for determining values of a pore cementation exponent m and/or a saturation exponent n for locations in a formation having similar petrophysical properties. Formation porosity, formation water saturation, and an apparent cementation exponent mn are obtained for the locations and their values are utilized to find the exponents. In one embodiment, the apparent cementation exponent and the formation water saturation are obtained from a dielectric logging tool.

Abstract: A composite electromagnetic (EM) system and method for measuring naturally occurring magnetic fields and controlled magnetic fields. The composite EM system includes a housing, an audio-magnetotelluric (AMT) system attached to the housing and measuring natural magnetic fields generated by earth, a frequency-domain EM (FDEM) system attached to the housing and measuring controlled magnetic fields generated by a controlled source, and a position and orientation (POS) system attached to the housing and configured to calculate an orientation and a position of the AMT system and housing relative to the earth. The housing is configured to be attached to an aircraft for being airborne while measuring the natural magnetic fields and the controlled magnetic fields.

Abstract: A method for making downhole electromagnetic logging measurements includes using an electromagnetic measurement tool to acquire the measurements while rotating in a subterranean wellbore. Received electromagnetic waves are processed to obtain harmonic voltage coefficients, ratios of which are in turn further processed to compute gain compensated measurement quantities. The gain compensated measurement quantities are further processed to compute at least one of an apparent formation azimuth of the formation through which the wellbore traverses, an apparent tool eccentering azimuth, and an eccentering distance of the logging tool in the wellbore.

Abstract: Systems and methods for estimating surface of fracture per volume of rock are provided. The systems include a logging tool, such as a resistivity tool, for generating a borehole image representative of segments of fractures in one or more planes and a processor for estimating surface of fracture per volume of rock (P32) from the segments without the need for defining the one or more planes bearing the segments. The methods include using a downhole logging tool, such as a resistivity tool, to collect data corresponding to segments of fractures in one or more planes, and estimating surface of fracture per volume of rock (P32) by reconstructing theoretical elliptical fractures from the segment data, calculating length of fracture segment per surface of borehole (P21) for the theoretical elliptical fractures, and deriving P32 from P21.

Abstract: A method for characterizing fractures traversing a wellbore includes input to a computer multiaxial electromagnetic induction measurements corresponding to measurements made along two mutually orthogonal magnetic dipole moment axes perpendicular to an axis of the wellbore. The measurements correspond to at least one receiver spacing from a transmitter. The measurements represent induced voltage in a receiver having a same dipole moment direction as a dipole moment direction of a transmitter. A first derivative with respect to wellbore depth of the multiaxial electromagnetic induction measurements is calculated. At least one peak and an amplitude thereof of the first derivatives is calculated. The peak and the amplitude are used to determine a location and an aperture of at least one fracture traversing the wellbore.

Abstract: Techniques for log squaring using both directional and non-directional electromagnetic measurements are disclosed. The techniques described herein can be used for determining bed boundary locations and assigning resistivity values to each layer in a layered earth model, regardless of well deviation. Potential bed boundary locations can be derived from both directional and non-directional electromagnetic measurement data. The bed boundary locations from the directional and non-directional measurements can then be consolidated using a weighted averaging scheme, where weight can be dependent based on apparent formation dip. By combining the results from both directional and non-directional measurements, the log squaring techniques described herein can be used in most wells regardless of the well angle (the angle can be arbitrary). Once bed boundaries are selected, formation properties, such as horizontal resistivity (Rh) and vertical resistivity (Rv) can be assigned to the model layers.

Abstract: A system and method determine formation permeability and/or at least one property indicative of formation permeability of a subsurface geological reservoir having radial-flow. Pressure data is obtained with an observation probe during a formation test, wherein the observation probe is located at a setting position within an open hole wellbore formed within the reservoir. The system and method measure radial-flow response of the reservoir at or adjacent to the setting position of the observation probe by analyzing the collected pressure data. The formation permeability and/or at least one property indicative of the permeability of the reservoir is determined based on the measured radial-flow response of the reservoir at or adjacent to the observation probe.

Abstract: The present disclosure relates, in some embodiments, to methods and systems of geosteering or geological operations. In some embodiments, systems of the present disclosure may transmit MWD or LWD data to a processor. The processor may extrapolate and convert the MWD or LWD data into KBTVD or pseudo-vertical data. Said extrapolation may be performed based on algorithmic expressions between the True Vertical Depth, the formation dip angle, and a Vertical Section Distance. In some embodiments, vertical data may be extrapolated by a processor and converted into pseudo-horizontal data. In some embodiments, systems may evaluate the formation dip angle and extrapolate a corrected true thickness of an interval layer. Screen representations of aforementioned data may be provided for. Embodiments of the present disclosure may provide for improved or more accurate data and/or virtualizations in the horizontal and/or vertical directions.

Abstract: A method for identifying fractures from measurements made by a multi-axial electromagnetic induction tool in a wellbore traversing subsurface formations includes determining a value of a fracture orientation indicator from in line components of the multi-axial electromagnetic induction measurements made transverse to a tool axis, and parallel to the tool axis. The tool axis is substantially parallel to a bedding plane of the subsurface formations. A value of a vertical fracture indicator is determined using the in line components of the multi-axial electromagnetic induction measurements made transverse to the tool axis, and parallel to the tool axis.

Abstract: A method for generating a porosity log for a reservoir in an organic shale. The method includes receiving data representing one or more parameters in a reservoir in an organic shale. At least one of the parameters includes porosity. By stochastically inverting the data, a distribution of porobodon features is estimated that matches an observed pulse decay curve. The porosity data relates to petrophysical restrictions on at least one of the porobodon features.

Abstract: Method and system for improving the speed and accuracy of determining formation properties using multiple logging data are disclosed. Logging data relating to the formation of interest is obtained and used as an input. High frequency noise is then removed from the logging data and bed-boundary determination is performed using the logging data. An adaptive low pass filter is applied to the logging data and the logging data is inverted. The inverted logging data is then visually interpreted.

Abstract: A wireless power transmitting device transmits wireless power signals to a wireless power receiving device using output circuitry that includes an array of wireless power transmitting coils that form a wireless charging surface. During wireless power transmission operations, wireless power signals are transmitted from the array of coils to a wireless power receiving device on the charging surface. Inductance measurement circuitry such as impulse response measurement circuitry and other measurement circuitry is coupled to the output circuitry. Control circuitry in the wireless power transmitting device analyzes signals from the measurement circuitry to produce two-dimensional signal profiles across the wireless charging surface and to compare patterns in these signal profiles to predetermined signal patterns associated with the presence of known power receiving equipment on the wireless charging surface. Based on the analysis, charging parameters may be adjusted or other actions taken.

Abstract: An apparatus for forming a water storage material from a biomass input material using supercritical or subcritical fluid processing, the water storage material capable of absorbing a liquid and releasing the liquid. The apparatus utilizes supercritical fluid processing, subcritical fluid processing, charring, or a combination thereof. The apparatus includes a controller configured to control the apparatus. The apparatus further including a processing station configured to hold the biomass input material, and to use the biomass input material for processing into the water storage material.

Abstract: A method can include selecting a location associated with a seismic survey geometry; selecting a trace for the location where the trace is selected from one of a plurality of different types of traces that include real data traces, interpolated data traces and model data traces; generating a multiple model based at least in part on the selected trace; and adjusting seismic data based at least in part on the multiple model.

Abstract: Systems and methods for reconstructing magnetic resonance (MR) tissue parameter maps of a subject from magnetic resonance fingerprinting (MRF) data acquired using a magnetic resonance imaging (MRI) system. The method includes providing MRF data acquired from a subject using an MRI system and performing an iterative, maximum-likelihood reconstruction of the MRF data to create MR tissue parameter maps of the subject.

Abstract: Methods and systems for estimating properties of formations penetrated by boreholes are provided, including conveying a carrier through a borehole having a transmitter, a first receiver, and a second receiver, the first receiver positioned a first distance from the transmitter and the second receiver positioned a second distance from the transmitter, generating a transient electromagnetic field with the transmitter, obtaining a total signal from signals received by the first receiver and the second receiver, performing a bucking calculation to obtain a pipe signal, applying a correction scheme to the total signal to generate a corrected formation property signal, wherein the correction scheme is Vcorr=Vmeas?P*Vmeas, wherein Vcorr is a correction signal, Vmeas is the total signal, and P is the pipe signal, estimating a formation property from corrected formation property signal to select a model of the formation, and adjusting a drilling operation based on the estimated property of the formation.

Abstract: Methods and systems for estimating properties of earth formations including conveying a carrier through a borehole having a transmitter, a first receiver, and a second receiver, the first receiver positioned a first distance from the transmitter and the second receiver positioned a second distance therefrom, generating with the transmitter a transient electromagnetic field, receiving a first measured signal at the first receiver, receiving a second measured signal at the second receiver, obtaining a total signal from the first measured signal and the second measured signal, determining a bucking coefficient, performing a bucking calculation employing the bucking coefficient, the first measured signal, and the second measured signal to extract a pipe signal, suppressing the pipe signal from the total signal to obtain a formation signal, estimating a formation property from the formation signal, and adjusting a drilling operation based on the estimated property of the formation.

Abstract: The connectivity between different pore types in porous media is measured by using low-field nuclear magnetic (NMR) and fast field cycling NMR techniques. Due to the fluid exchange between connected pores, T1(T2) NMR relaxation times of proton nuclei of fluids in the different pore types are shifted. By comparing the T1(T2) NMR relaxation times of porous media samples which are 100% brine saturated with relaxation times for the samples containing brine and hydrocarbon in the different pore systems of the samples, the connectivity between the pores can be measured.

Abstract: Techniques for determining an amount of chert in a rock formation include identifying first logging data for a selected zone of a first subterranean formation that includes chert, quartz, and zircon; identifying second logging data for a second subterranean formation that is different than the first subterranean formation, the second subterranean formation including chert, quartz, and zircon; determining a first volumetric ratio of quartz to zircon in the selected zone based on the first logging data; determining a second volumetric ratio of quartz to zircon based on the second logging data; determining a maximum value of the second volumetric ratio; and calculating, based on the first and second volumetric ratios and the maximum value of the second volumetric ratio, a volumetric percentage of chert in the selected zone.

Abstract: Embodiments of the disclosure involve a method comprising a method comprising inputting borehole dip data; determining characteristics of a plurality of dips based on the borehole dip data; applying one or more geological models to the characteristics; and generating one or more geological cross-sections based on geological modeling.

Abstract: An example method for downhole surveying and measuring may include positioning a first conformable sensor proximate to a downhole element. The first conformable sensor may include a flexible material, a transmitter coupled to the flexible material, and a receiver coupled to the flexible material. A response of the downhole element to a signal generated by the transmitter may be measured at the receiver. The response may be processed to determine a feature of the downhole element.

Abstract: Tools, systems and methods for fast formation dip angle estimation, at least some of which include a logging tool that includes at least one transmit antenna, at least one receive antenna and a controller. The controller measures coupling parameters between the transmit and receive antennas, with at least one of the coupling parameters being measured as a function of depth and azimuthal angle. The controller further determines if a surrounding formation is anisotropic and heterogeneous based at least in part on at least one of the coupling parameters, and if so, derives a dip angle from a partial derivative with respect to depth and artificial dip angle of the coupling parameter(s).

Abstract: A method of modeling electromagnetic heating for oil recovery for a wide range of frequencies includes arranging a plurality of electrodes and/or antennas in an array in a multi-layer earth model of a reservoir formation, wherein the arranging includes selecting a number of electrodes/antennas and an array topology; selecting a frequency of the array; determining a temperature profile of the reservoir using the frequency and reservoir formation characteristics; providing the a heat rate to a reservoir simulator; inputting reservoir characteristics into the reservoir simulator; calculating, by processor, an oil recovery production rate of the reservoir based on the heat rate and reservoir characteristics; and graphically displaying the oil recovery production rate.

Abstract: Apparatus and techniques are described, such as for obtaining information indicative of a formation resistivity, such as using information from a galvanic measurement apparatus. A resistive parameter related to a geologic formation is estimated through use of a model. An electrical excitation is coupled from a well tool in a borehole to the geologic formation. Induced voltages resulting from the excitation are received using monitor electrodes selected according to the specified excitation mode, including receiving magnitude and phase information corresponding to the induced voltages. The resistive parameter of the model is then determined using the magnitude and phase information of the received voltages, and using magnitude and phase information about the excitation.

Abstract: A method for inverting dielectric logging tool measurement data to estimate an electrical characteristic of an earth formation includes: receiving measurement data from the logging tool having a transmitter antenna and receiver antennas spaced known distances from the transmitter antenna; establishing an equation relating magnetic field measurements made by the receiver antennas to the distances and a wave vector; establishing an error equation that quantifies a difference between the magnetic field measurements made by the receiver antennas to magnetic field measurements made by the receiver antennas that would be obtained with an estimated formation electrical characteristic; calculating an error using the error equation for an initial estimated value of the wave vector that comprises a term having a first number multiplied times a second number of radians to provide a plurality of calculated errors; and determining a minimum error from the plurality of calculated errors to estimate the electrical character

Abstract: A positioning device for determining an object depth of a concealed positioning object includes a first positioning sensor, a second positioning sensor, and a computation unit. The computation unit can determine the object depth using at least a first positioning characteristic variable of the first positioning sensor. The computation unit can also correct the determined object depth in at least one operating state using a second positioning characteristic variable of the second positioning sensor.

Abstract: System and methods for defining non-linear petrofacies for a reservoir simulation model are provided. A cross-plot visualization of selected petrophysical properties from a three-dimensional (3D) geocellular grid array of petrophysical properties representing a reservoir rock formation is presented to a user via a display of a computing device. Upon receiving user input for defining a non-linear petrofacies region of the 3D geocellular grid within the presented cross-plot visualization, data points in the cross-plot visualization that are within the boundaries of the petrofacies region are identified. The identified data points are associated with the petrofacies region. Hydraulic rock properties are assigned to one or more cells of the 3D geocellular grid based on the data points associated with the petrofacies region.

Abstract: The disclosure relates to the fields of geology and geotechnics, and to a system for description of vertical sequences of rocks in cores and outcrops. The system and process provide a way to describe vertical sequences of rocks in digital media through gestures on a device equipped with a touchscreen. The process allows inserting data simply and quickly and uses a geological feature vocabulary and a library of standardized icons, an aspect that eliminates the heterogeneity of the data obtained in diverse descriptions and allows analyzing the captured data automatically by computer. The benefits include, but are not limited to: elimination of vocabulary heterogeneity and description formats of vertical sequences of rocks; generation of customized reports; data export to files with standardized formats for data exchange among software applications; reduction of the time used in the description; reduction of the time used to generate technical reports.

Abstract: A method for obtaining gain corrected triaxial electromagnetic propagation measurements with an offset correction includes deploying an electromagnetic logging tool in a subterranean borehole. The logging tool includes at least first and second axially spaced triaxial transmitters and at least first and second axially spaced triaxial receivers. A plurality of full tensor voltage measurements may be acquired and processed tensor term by tensor term to obtain a full tensor, gain corrected quantity. The processing may optionally include (i) removing a full tensor voltage offset from the acquired full tensor voltage measurements to obtain a corresponding plurality of offset corrected voltage tensors and (ii) processing the offset corrected voltage tensor term by tensor term to obtain the full tensor, gain and offset corrected quantity.

Abstract: In some embodiments, a multi-array induction method uses user selectable zoning of a borehole to generate an updated look-up table for borehole corrections based on averaged calipers for the borehole. One example method averages caliper data, defines a good zone of the borehole substantially unaffected by corkscrew borehole effect, defines a start depth and an end depth of a zone of the borehole affected by the corkscrew borehole effect, and averages the caliper data for each coil array to generate updated resistivity outputs RO, Rt, and Rf for further drilling of the borehole.

Abstract: Methods and apparatuses are provided for analyzing a composition of a hydrocarbon-containing fluid. The methods include using a nuclear magnetic resonance (NMR) tool to conduct an NMR measurement on the hydrocarbon-containing fluid to obtain NMR data. A non-NMR tool, such as an optical tool, is used to conduct additional measurements on the hydrocarbon-containing fluid and to obtain non-NMR data on the fluid. An indication of the composition of the fluid can be determined by using the NMR data and the non-NMR data in an inversion process.

Abstract: Systems and methods for determining stresses in pipe under non-uniform exterior loads to test the pipe design for structural integrity by approximating non-uniform exterior loads on the pipe and performing a stress analysis of the pipe under the non-uniform exterior loading to determine the stresses in the pipe.

Abstract: Methods and apparatuses for geophysical surveying are disclosed. In one embodiment, a marine vehicle may obtain magnetic measurements in a location around a drilling site. The magnetic measurements may be used to calculate a localized disturbance magnetic field resulting from, for example, solar flares. The localized disturbance magnetic field may be used to calculate a declination value and, thus, a wellbore position with improved accuracy.

Abstract: Various embodiments include apparatus and methods of operation with respect to well logging. Apparatus and methods include a tool having an arrangement of transmitters and receivers that are operated at different positions downhole and a processing unit to process collected signals such that the arrangement of transmitters and receivers provides measurements that mimic operation of a different arrangement of transmitters and receivers. Additional apparatus, systems, and methods are disclosed.

Abstract: A technique utilizes the acquisition of data from desired subterranean regions via a logging system. The logging system is constructed for use in a wellbore and comprises a transmitter module having a transmitter antenna. Additionally, the logging system utilizes a receiver module spaced from the transmitter module and having a receiver antenna. The transmitter antenna and the receiver antenna are oriented to enable sensitivity in desired directions, such as ahead of the logging system.

Abstract: A method for estimating a property of an earth formation penetrated by a borehole includes conveying a drill tubular through the borehole and transmitting a signal into the formation with a transmitter transducer disposed at the drill tubular. The method further includes receiving a first signal with a first receiver transducer having a sensitivity oriented in a first direction and disposed an axial distance from the transmitter transducer and receiving a second signal with a second receiver transducer having a sensitivity oriented in a second direction different from the first direction and disposed an axial distance from the transmitter transducer. The method also includes calculating a corrected signal that corrects for at least one of bending and torsion of the drill tubular between the transmitter transducer and the first and second receiver transducers using the first signal and the second signal and estimating the property using the corrected signal.

Abstract: Disclosed herein are electromagnetic resistivity logging systems and methods that employ an antenna configuration having at most two transmitter or receiver antenna orientations that rotate relative to the borehole. The measurements made by this reduced-complexity antenna configuration enable the determination of at least seven components of a coupling matrix, which may be determined using a linear system of equations that express the azimuthal dependence of the measurements. For increased reliability, measurement averaging may be performed in azimuthally spaced bins. The coupling matrix components can then be used as the basis for determining logs of various formation parameters, including vertical resistivity and anisotropy.

Abstract: Various embodiments include apparatus and methods of operation with respect to well logging. Apparatus and methods include a tool having an arrangement of transmitters and receivers to capture a signal from a first region relative to the tool such that signal contributions from a second region relative to the tool are cancelable, based on placement of the transmitters and receivers with respect to each other. Additional apparatus, systems, and methods are disclosed.

Abstract: Method for reducing a 3D joint inversion of at least two different types of geophysical data acquired by 3-D surveys to an equivalent set of 1D inversions. First, a 3D inversion is performed on each data type separately to the yield a 3-D model of a physical property corresponding to the data type. Next, a 1D model of the physical property is extracted at selected (x,y) locations. A 1D simulator and the 1D model of the physical property is then used at each of the selected locations to create a synthetic 1D data set at each location. Finally, the 1D synthetic data sets for each different type of geophysical data are jointly inverted at each of the selected locations, yielding improved values of the physical properties. Because the joint inversion is a 1D inversion, the method is computationally advantageous, while recognizing the impact of 3-D effects.

Abstract: A method of constructing a reservoir flow model from capillary pressure curves (Pc) and/or relative permeability curves (Kr) is disclosed having application to petroleum reservoir development, acid gas storage and underground water management. After discretizing the reservoir into a set of cells, a principal component analysis is performed for a data table constructed from curves (Pc, Kr) so as to extract principal factors explaining the data. The curves are represented in a representation space constructed from these principal factors and the curves represented in the representation space are classified. At least one curve representative of each class resulting from this classification is then defined and associated with each cell.

Abstract: To perform marine electromagnetic (EM) surveying of a subterranean structure, a marine cable system is provided including a tow cable, a plurality of electromagnetic (EM) sources coupled to the tow cable, and a plurality of EM receivers coupled to the tow cable. The system is configured for deployment in a body of water to perform marine EM surveying of a subterranean structure.

Abstract: A multi-step electromagnetic inversion method is provided for determining formation resistivity, anisotropy and dip. An electromagnetic logging tool is used to obtain non-directional, anisotropy, and directional (including symmetrized and anti-symmetrized resistivity measurements) in a formation using an electromagnetic logging tool. Bed boundaries of the formation are first identified. A horizontal resistivity profile is obtained using the non-directional resistivity measurements, and a vertical resistivity profile is obtained using the anisotropy resistivity measurements. The vertical resistivity profile is improved using the directional resistivity measurements, while dip values are also obtained via an inversion using the directional resistivity measurements. Then, an inversion for each of vertical resistivity, horizontal resistivity, dip values, and bed boundaries is performed using all of the non-directional, anisotropy, and directional resistivity measurements to obtain a formation model.

Abstract: The present disclosure relates to a method to determine a volume of clearance surrounding a wellbore. A logging tool is provided. The logging tool may be disposed on a wireline, a drill string, or a wired drill pipe. A formation property is obtained using the logging tool. The formation property may include a voltage, a bulk resistivity, a horizontal resistivity, a vertical resistivity, a porosity, a permeability, a fluid saturation, an NMR relaxation time, a borehole size, a borehole shape, a borehole fluid composition, an MWD parameter, or an LWD parameter. The maximum depth of investigation into the subsurface formation is determined using a model response and a noise level, and the volume of clearance is determined using the determined maximum depth of investigation. The maximum depth of investigation and volume of clearance may be determined even though no boundary layers are detected.

Abstract: Method and apparatus for estimating a resistivity property of an earth formation in a borehole with oil-based drilling fluid. The method may include estimating the resistivity property using a sensitivity of a real part of a measured impedance to a reactance of a gap between a resistivity sensor and a borehole wall. The real component and the quadrature component of resistivity measurements made by a two-terminal imaging tool in a borehole having an oil-based mud are affected by the tool standoff. It is shown that the sensitivity of the real part of the resistivity measurement to the reactance of the gap can be estimated from the time derivatives of the two components of the measurements. This makes possible a principal component analysis of the data to give an improved image of the formation resistivity.

Abstract: Various embodiments include apparatus and methods to make resistivity measurements in a borehole using tool having an array of electrodes operable to provide focused currents and measure corresponding voltages to determine resistivity. Tools can be configured with a main electrode having a number of spaced apart electrodes within the main electrode such that the spaced apart electrodes are arranged azimuthally with respect to an axis of the tool. Generation of current from the spaced apart electrodes and control of current from additional electrodes on each side of the main electrode can provide for focused measurements. Additional apparatus, systems, and methods are disclosed.

Abstract: Methods of generating structural models of highly deviated or horizontal wells may be generated from the measurement of true stratigraphic thickness in three dimensions (TST3D). In one aspect, methods may include generating a structural model from one or more deviation surveys of a horizontal well, one or more single channel log measurements, and a three-dimensional reference surface.

Abstract: A system and method to determine a dip angle and an azimuth angle of a formation are described. The system includes a transmitter disposed in a borehole to change a transmitted current to induce a current in an earth formation, and a receiver disposed in the borehole, spaced apart from the transmitter, to receive transient electromagnetic signals. The system also includes a processor to extract multi-time focusing (MTF) responses from the transient electromagnetic signals, determine a relative dip angle and a rotation of a tool comprising the transmitter and receiver based on the MTF responses, and estimate the dip angle and the azimuth angle of the formation based on the relative dip angle and the rotation of the tool.