Abstract: Disclosed herein are embodiments of systems, methods, and computer program products for assessing the data-quality of the calculated reservoir-rock resistivity Rsd in laminar formations. For instance, in one embodiment, a computer-implemented method for assessing the data-quality of the calculated reservoir-rock resistivity Rsd in laminar formations comprises the steps of receiving multi-component induction (MCI) data and other sensor logs data associated with a laminar formation; determining a set of calculated reservoir-rock resistivity Rsd using at least one of the multi-component induction (MCI) data and other sensor logs data; and performing data quality assessments of the set of calculated reservoir-rock resistivity Rsd.

Abstract: A method to minimize borehole effects upon a multi-component induction tool within a well and borehole with water-based mud includes measuring parameters of the reservoir with the induction tool to create an array of measured components. The method further includes comparing a measured component from the array of measured components with a corresponding model component from an array of model components for a reservoir model with known parameters and no borehole effects, and determining the parameters for the reservoir based upon the comparison of the measured component and the corresponding model component.

Abstract: Evaluation of formation and fracture characteristics based on multicomponent induction (MCI) log data includes automated calculation of inverted biaxial anisotropy (BA) parameters for the formation by performing an iterative BA inversion operation based on the MCI log data and using a BA formation model that accounts for transfers by axial formation anisotropy to resistivity. The BA inversion operation can be combined with a transversely anisotropic (TI) inversion based on the MCI log data and using a TI formation model, to calculate inverted TI parameters for the formation. The inverted BA parameters and the inverted TI parameters can be used, in combination, to calculate a quantified value for an identification function, to indicate estimated presence or absence of a fracture in the formation.

Abstract: Various resistivity logging tools, systems, and methods are disclosed. At least some system embodiments include a logging tool and at least one processor. The logging tool provides transmitter-receiver coupling measurements that include at least direct coupling along the longitudinal tool axis (Czz), direct coupling along the perpendicular axis (Cxx or Cyy), and cross coupling along the longitudinal and perpendicular axes (Cxz, Cyz, Czx, or Czy). The processor performs a multi-step inversion of said transmitter-receiver coupling measurements to obtain values for model parameters. Based at least in part on the model parameters, the processor determines borehole corrections for the transmitter-receiver coupling measurements and may further provide one or more logs derived from the borehole corrected transmitter-receiver coupling measurements.

Abstract: At least some disclosed resistivity logging system embodiments include a logging tool and a processing system. The logging tool provides multi-component transmitter-receiver coupling measurements to the processing system. The processing system derives from the measurements initial formation parameter estimates based on a first formation model such as a radially-symmetric formation model having anisotropic, but otherwise homogenous dipping formation. The processing system further derives in one or more selected regions a second set of formation parameter estimates based on a second formation model such as a model having a dipping borehole through a series of horizontal formation layers, each having a vertical transverse isotropy.

Abstract: The quality of processed MCI logging data is assessed using quality indicators (“QIs”) including, for example, an oval-hole effect QI, formation-invasion effect QI, shoulder effect QI, biaxial anisotropy (“BA”) effect QI, or dip-difference effect QI. The QIs are applied to express their respective effects on the formation property data. Once the data quality has been assessed, a QI borehole formation model is selected based upon the assessment. The QI borehole formation model is then applied to determine true formation property data, which is then used to determine formation porosity, saturation, permeability, etc. of the formation.

Abstract: Various resistivity logging tools, systems, and methods are disclosed. At least some system embodiments include a logging tool and at least one processor. The logging tool provides transmitter-receiver coupling measurements that include at least direct coupling along the longitudinal tool axis (Czz), direct coupling along the perpendicular axis (Cxx or Cyy), and cross coupling along the longitudinal and perpendicular axes (Cxz, Cyz, Czx, or Czy). The processor combines a plurality of the coupling measurements to obtain inversion parameters. Based at least in part on the inversion parameter, the processor performs an inversion process to determine a vertical conductivity and, based in part on the vertical conductivity, determines borehole corrected values for said transmitter-receiver coupling measurements. One or more of the borehole corrected values can be provided as a function of borehole position.

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: Various embodiments include apparatus and methods to provide a skin-effect correction. The skin-effect correction can be based on a pre-calculated correction coefficient library. In various embodiments, a skin-effect correction procedure can be applied that only uses a single-frequency R-signal measurement. In addition, an embodiment of a skin-effect correction procedure using a single-frequency R-signal measurement can be applied whenever the quality of the data from one of the multiple frequencies normally used in a multi-frequency method is reliable. Additional apparatus, systems, and methods are disclosed.

Abstract: In some embodiments, an apparatus and a system, as well as a method and an article, may operate to calculate a map that transforms fast modeled measurement results into accurate modeled measurement results within a modeled data space, to make actual measurements using a tool disposed in a borehole, to transform a plurality of modeling parameter vectors into the fast modeled measurement results via modeling, to transform the fast modeled measurement results into the accurate modeled measurement results using the map, to locate a matching modeling parameter vector as one of the plurality of modeling parameter vectors that matches the accurate modeled measurement results to the actual measurement, and to display at least a portion of the matching modeling parameter vector to represent at least one property of a geological formation. Additional apparatus, systems, and methods are described.

Abstract: Formation properties may be more efficiently derived from measurements of multi-frequency, multi-component array induction tools, by emphasizing the measurements associated with shorter spacings/lower frequencies in certain regions and short-to-middle spacings/higher frequencies in other regions. In at least one embodiment, a disclosed logging system includes a logging tool that when conveyed along a borehole through a formation obtains multi-component transmit-receive antenna coupling measurements with multiple arrays having different antenna spacings; and a processing system that operates on the measurements. The processing system derives from said measurements one or more formation parameter estimates; determines measurement weight coefficients for a cost function based on said one or more formation parameter estimates; and inverts said measurements with said cost function to obtain one or more enhanced parameter estimates.

Abstract: The processing of multicomponent induction (“MCI”) data in non-circular, or elliptical, boreholes is achieved through the use of borehole formation models generated using elliptical borehole characteristics.

Abstract: According to at least some embodiments, a method of processing inversion results corresponding to a plurality of parameters of a subterranean formation includes obtaining measurements of the subterranean formation from a multi-component induction (MCI) tool. The method further includes inverting the measurements to determine a first estimated value of a parameter of the plurality of parameters. The method further includes determining at least a second estimated value of the parameter, and assessing a quality of the inverted measurements by comparing the first estimated value with the at least a second estimated value.

Abstract: Evaluation of formations and fracture characterization based on multicomponent induction (MCI) log data includes automated calculation of biaxial anisotropy (BA) parameters by performing iterative inversion operations based on the MCI log data. Biaxially anisotropic effect corrected (BAC) logs are BA anisotropic effect corrected using the inverted BA parameters. The inverted BA parameters can also be used for identification and quantification of fractures in formations.

Abstract: A system for determining a wettability associated with a subterranean formation can include a dielectric logging tool, a resistivity logging tool, a pulsed neutron tool, and a computing device. The dielectric logging tool can transmit a first data set associated with the subterranean formation. The resistivity logging tool can transmit a second data set associated with the subterranean formation. The pulsed neutron tool can transmit a third data set associated with the subterranean formation. The computing device can be in communication with the dielectric logging tool, the resistivity logging tool, and the pulsed neutron tool. The computing device can receive the first data set, the second data set, and the third data set and determine the wettability associated with the subterranean formation based on the first data set, the second data set, and the third data set.

Abstract: Methods and a system are described, such as for correcting multicomponent logging data. The method measures geological formation resistivity to generate formation resistivity data. Borehole correction (BHC) is performed on the formation resistivity data to remove a borehole effect and generate BHC log data. A forward model is selected from a plurality of forward models based on the formation resistivity data. A dip-effect on the BHC log data is determined based on the selected forward model. The dip-effect is removed from the BHC log data to generate dip-effect corrected BHC log data.

Abstract: A method and system can include a sensor positioned in a borehole, characteristics of the earthen formation can be measured and logged by the sensor, and an effective permeability can be determined based on the logged characteristics. Multi-component induction (MCI) data can be measured by a logging tool, 3D resistivity components can be determined by inverting the MCI data, and the 3D resistivity components can be logged. Tri-axial permeability components can be determined based on the effective permeability and the 3D resistivity component logs. A permeability of sand in the earthen formation can be determined based on the tri-axial permeability components, the effective permeability, and a laminated shale volume. The sand permeability can be logged and modifications to operation(s) can be initiated based on the sand permeability.

Abstract: Evaluation of formation and fracture characteristics based on multicomponent induction (MCI) and multipole sonic logging (MSL) data includes automated calculation of inverted biaxial anisotropy (BA) parameters for the formation by performing an iterative BA inversion operation based on the MCI log data and using a BA formation model that accounts for transfers by axial formation anisotropy to resistivity. The inverted BA parameters and the processed MSL data can be used, in combination, to calculate a quantified value for an identification function, to indicate estimated presence or absence of a fracture in the formation.

Abstract: In some embodiments, an apparatus and a system, as well as methods, include operating to estimate a range of true resistivity in a geological formation, based on measurements made over multiple frequencies. Further activity may comprise selecting a subset of the measurements associated with at least one measurement frequency included in the multiple frequencies, based on the range of the true resistivity, to determine a value of a property of the geological formation. Additional methods, apparatus, and systems are disclosed.

Abstract: The processing of multicomponent induction (“MCI”) data in non-circular, or elliptical, boreholes is achieved through the use of borehole formation models generated using elliptical borehole characteristics.