Abstract: Methods are provided for determining values for a set of parameters for multiple locations in a formation by inversion of formation data obtained from a plurality of different logging tools. The inversion of the formation data is constrained by certain formation data that characterizes each particular location in the formation as obtained from at least one of the plurality of different logging tools. In one embodiment, the set of parameters for each particular location in the formation includes an apparent cementation factor mn and a formation water saturation Sw, which can be derived by inverting dielectric data that characterizes the particular location in the formation as obtained from a dielectric logging tool. The methods can also be adapted to characterize a porous medium such as reservoir rock, particular with regard to laboratory analysis of porous media samples.

Abstract: Methods and systems are provided for conducting formation analysis. Data from borehole logging tools is used to conduct a petrophysical analysis of the formation in order to determine (quantify) total porosity and formation matrix permittivity for an interval of the formation. Noninvaded zone water saturation and flushed zone water saturation for the interval of the formation is determined using a saturation model of the interval. The noninvaded zone water saturation is compared to the flushed zone water saturation, and the results of the comparison are used to determine that the interval of the formation contains movable hydrocarbon, immobile hydrocarbon or movable formation water.

Abstract: Methods and systems for determining petrophysical parameters of a formation are provided. In one embodiment, a method includes acquiring formation data with a borehole imaging tool deployed in a well penetrating a formation and acquiring additional formation data with a dielectric logging tool deployed in the well. The method also includes calibrating the formation data acquired with the borehole imaging tool based on the additional formation data acquired with the dielectric logging tool. The calibrated formation data can then be used in determining a petrophysical parameter of the formation. Additional methods, systems, and devices are also disclosed.

Abstract: Methods are provided for determining values for a set of parameters for multiple locations in a formation by inversion of formation data obtained from a plurality of different logging tools. The inversion of the formation data is constrained by certain formation data that characterizes each particular location in the formation as obtained from at least one of the plurality of different logging tools. In one embodiment, the set of parameters for each particular location in the formation includes an apparent cementation factor mn and a formation water saturation Sw, which can be derived by inverting dielectric data that characterizes the particular location in the formation as obtained from a dielectric logging tool. The methods can also be adapted to characterize a porous medium such as reservoir rock, particular with regard to laboratory analysis of porous media samples.

Abstract: A method includes receiving, via a processor, dielectric measurements of a geological formation and receiving, via the processor, sigma measurements. The sigma measurements include thermal neutron capture cross section of the geological formation. The method also includes jointly inverting to fit the dielectric measurements and the sigma measurements to a petrophysical model, and computing at least water salinity of the geological formation based on the joint inversion.

Abstract: The disclosure provides methods and systems for evaluating formation geometry and petrophysical properties directly from raw electromagnetic measurements. The methods involve using a downhole tool to measure a property of a formation at multiple depths of investigation and calculating geometry and petrophysical property information by direct inversion from raw measurements acquired by the tool. The system includes a tool for measuring a formation property at different depths of investigation and a processor for calculating geometry and petrophysical information by direct inversion from the raw measurements acquired by the tool.

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: Techniques involve obtaining dielectric measurements measured from a dielectric logging tool investigating a borehole at a one or more frequencies in a first frequency range, obtaining inductive measurements measured from an inductive tool investigating the borehole at one or more frequencies in a second frequency range, where the second frequency range is higher than the first frequency range, estimating an estimated resistivity anisotropy by conducting an inversion on the dielectric measurements, computing a measured resistivity anisotropy by conducting an inversion on the inductive measurements, and determining a characteristic related to reservoir fluids in the borehole, based on a comparison of the estimated resistivity anisotropy and the measured resistivity anisotropy.

Abstract: Methods and systems for determining petrophysical parameters of a formation are provided. In one embodiment, a method includes acquiring formation data with a borehole imaging tool deployed in a well penetrating a formation and acquiring additional formation data with a dielectric logging tool deployed in the well. The method also includes calibrating the formation data acquired with the borehole imaging tool based on the additional formation data acquired with the dielectric logging tool. The calibrated formation data can then be used in determining a petrophysical parameter of the formation. Additional methods, systems, and devices are also disclosed.

Abstract: In one embodiment, a method includes receiving, via a processor, dielectric measurements of a geological formation and receiving, via the processor, sigma measurements. The sigma measurements include thermal neutron capture cross section of the geological formation. The method also includes jointly inverting to fit the dielectric measurements and the sigma measurements to a petrophysical model, and computing at least water salinity of the geological formation based on the joint inversion.

Abstract: Techniques involve obtaining dielectric measurements measured from a dielectric logging tool investigating a borehole at a one or more frequencies in a first frequency range, obtaining inductive measurements measured from an inductive tool investigating the borehole at one or more frequencies in a second frequency range, where the second frequency range is higher than the first frequency range, estimating an estimated resistivity anisotropy by conducting an inversion on the dielectric measurements, computing a measured resistivity anisotropy by conducting an inversion on the inductive measurements, and determining a characteristic related to reservoir fluids in the borehole, based on a comparison of the estimated resistivity anisotropy and the measured resistivity anisotropy.

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: The disclosure provides methods and systems for evaluating formation geometry and petrophysical properties directly from raw electromagnetic measurements. The methods involve using a downhole tool to measure a property of a formation at multiple depths of investigation and calculating geometry and petrophysical property information by direct inversion from raw measurements acquired by the tool. The system includes a tool for measuring a formation property at different depths of investigation and a processor for calculating geometry and petrophysical information by direct inversion from the raw measurements acquired by the tool.

Abstract: Apparatus and methods for determining the rock solid (matrix) dielectric permittivity for subterranean rocks, such as carbonate rocks, are described. According to some embodiments, this is accomplished by linking the matrix permittivity to the detailed chemical composition of the rock. The linking function is defined by coefficients for each component that can be determined by inversion in a laboratory calibration process such that the function compensates for the permittivity contribution of rock components that may be undetectable through downhole logging procedures.

Abstract: A method of simultaneously determining multiple parameters or a parameter distribution characterizing material properties of a volume under investigation using an inversion process of sparse measurements is described including the step of defining an initial model of the volume and modifying the initial model by matching the multiple parameters or parameter distribution with the measurements using alternatingly an iterative inversion method and a probabilistic inversion method, and determining the multiple parameters or parameter distribution after one or more iterations of the alternating inversions.

Abstract: A method for assigning a wettability or related parameter to a subvolume of formation located between two or more boreholes is described. The method includes the steps of obtaining measurements of resistivity at a subvolume, obtaining further parameters determining a relation between resistivity and saturation from logging measurements along the two or more boreholes, obtaining geological measurements defining geological or rock-type boundaries within the formation between the two or more boreholes, selecting the subvolume such that it is intersected by the geological or rock-type boundaries; transforming the resistivity measurements into the saturation at the subvolume; and using the saturation and/or the further parameters to determine the wettability or related parameter for the subvolume.

Abstract: Apparatus and methods for determining the rock solid (matrix) dielectric permittivity for subterranean rocks, such as carbonate rocks, are described. According to some embodiments, this is accomplished by linking the matrix permittivity to the detailed chemical composition of the rock. The linking function is defined by coefficients for each component that can be determined by inversion in a laboratory calibration process such that the function compensates for the permittivity contribution of rock components that may be undetectable through downhole logging procedures.

Abstract: A method of determining the dip or apparent dip of a section of a subterranean formation is described using the measurements of a borehole gravity meter and a dip-dependent model for the response of the gravity meter.

Abstract: A method of performing gravity surveys in a wellbore is described including performing a time-lapse measurement in a monitoring well in the vicinity of injector wellbores, determining a depth for which the difference of the time lapse measurements changes sign or crosses zero as depth of the anomaly; and using said measurements at other depth points to further determine one or more parameters relating to the location and/or size of a density anomaly caused by injecting fluids through said injector wellbores, thus enabling the sweep of an injected fluid including the occurrence of fingering in the formation.

Abstract: A method for assigning a wettability or related parameter to a subvolume of formation located between two or more boreholes is described with the method including the steps of obtaining measurements of the resistivity at the subvolume, obtaining further parameters determining a relation between resistivity and saturation from logging measurements along the two or more boreholes, obtaining geological measurement defining geological or rock-type boundaries within the formation between the two or more boreholes, selecting the subvolume such that it is not intersected by the geological or rock-type boundaries; transforming the resistivity measurements into the saturation at the subvolume; and—using the saturation and/or the further parameters to determine the wettability or related parameter for the subvolume.