Abstract:
A tool is for use in a borehole during drilling with a drilling fluid circulating in the borehole. The tool may include a housing, a plurality of spaced apart radio frequency (RF) transmitters carried by the housing, spaced apart RF receivers carried by the housing, and a controller to communicate with the plurality of transmitters and the receivers. The controller may, at a given depth within the borehole, determine attenuation resistivity measurements and phase-shift resistivity measurements both corresponding to different radial distances from the borehole. The controller may also determine when a fracture has occurred in the geological formation at the given depth allowing the drilling fluid to intrude into the geological formation based upon the attenuation resistivity measurements and the phase-shift resistivity measurements.
Abstract:
A system and method discloses performing a fracture operation at a wellsite about a subterranean formation. The method involves, obtaining wellsite measurements by placing a downhole tool in a wellbore and using the downhole tool to acquire measurements of the subterranean formation, simulating the obtained wellsite measurements to determine formation parameters comprising conductivity tensors based on a formation model of the measured subterranean formation, validating the formation model by comparing the obtained wellsite measurements with the simulated wellsite measurements, generating fracture parameters and triaxiality indicators based on the validated formation model, and fracturing the subterranean formation based on the generated fracture parameters and triaxiality indicators.
Abstract:
Techniques involve determining the frequency-dependent dielectric permittivity spectrum of a rock sample. Determining the frequency-dependent dielectric permittivity may involve defining a series of electromagnetic measurement data having at least a measurement at a frequency from which a substantially frequency-independent value of dielectric permittivity ε∞ can be obtained. The electromagnetic measurement data also includes measurements at different frequencies from which values for frequency-dependent dielectric permittivity εrock (f) can be obtained. Using these measurements, the frequency-dependent spectrum of the sample may be determined.
Abstract:
A method to determine at least one formation property of a subterranean formation includes providing a downhole electromagnetic logging tool having at least one transmitter array and one receiver array to acquire measurements in the formation. The method further includes performing a first inversion in response to the measurements, assuming dip or dip azimuth is constant in an inversion zone within the formation to obtain an inverted formation model. The method includes determining an n-th order partial derivative matrix of at least one of dip or dip azimuth, wherein n is greater than or equal to 1. The method includes performing a second inversion using the determined n-th order partial derivative matrix, wherein at least one of dip and dip azimuth are allowed to vary in the inversion zone, to obtain an updated formation model. The method includes determining the formation property using the updated formation model.
Abstract:
A system and method of performing a fracture operation at a wellsite about a subterranean formation is disclosed. The method involves, obtaining wellsite measurements by placing a downhole tool in a wellbore and using the downhole tool to acquire measurements of the subterranean formation, simulating the obtained wellsite measurements to determine formation parameters comprising conductivity tensors based on a formation model of the measured subterranean formation, validating the formation model by comparing the obtained wellsite measurements with the simulated wellsite measurements, generating fracture parameters and triaxiality indicators based on the validated formation model, and fracturing the subterranean formation based on the generated fracture parameters and triaxiality indicators.
Abstract:
Techniques involve determining the frequency-dependent dielectric permittivity spectrum of a rock sample. Determining the frequency-dependent dielectric permittivity may involve defining a series of electromagnetic measurement data having at least a measurement at a frequency from which a substantially frequency-independent value of dielectric permittivity ∈∞ can be obtained. The electromagnetic measurement data also includes measurements at different frequencies from which values for frequency-dependent dielectric permittivity ∈rock (f) can be obtained. Using these measurements, the frequency-dependent spectrum of the sample may be determined.
Abstract:
A method to determine at least one formation property of a subterranean formation includes providing a downhole electromagnetic logging tool having at least one transmitter array and one receiver array and acquiring measurements in the formation using the transmitter and receiver arrays of the downhole electromagnetic logging tool. The method further includes performing a first inversion in response to the measurements, wherein at least one of dip or dip azimuth are assumed constant in an inversion zone within the formation to obtain an inverted formation model that comprises at least one of horizontal resistivity (Rh), vertical resistivity (Rv), dip, and dip azimuth. The method includes determining an n-th order partial derivative matrix of at least one of dip or dip azimuth, wherein n is greater than or equal to 1. The method includes performing a second inversion using the determined n-th order partial derivative matrix, wherein at least one of dip and dip azimuth are allowed to vary in the inversion zone, to obtain an updated formation model. The method includes determining the at least one formation property of the formation using the up-dated formation model.