Schlumberger Technology Corporation

Siddharth Misra

Dean M Homan

John C Rasmus

Gerald N Minerbo

Yuteng Jin

Carlos Torres-Verdin

Aditya Gupta

Aspects of the present disclosure relate to a method for determining a contact angle, a wettability, or both, of one or more types of solid particles within a geological formation. The method may include identifying a relative conductive of the type of solid particles and identifying a frequency range for one or more EM measurements. The method may also include determining a contact angle associated with at least one type of solid particles within the geological formation using the electromagnetic measurements corresponding to the frequency range.

Systems and methods for determining properties of porous, fluid-filled geological formations based on multi-frequency measurements

Aspects of the present disclosure relate to a method for determining a wettability of one or more types of solid particles within a geological formation. The method may include receiving a plurality of electromagnetic measurements within a frequency range from an electromagnetic well-logging tool. The method may also include determining a contact angle associated with at least one type of solid particles within the geological formation using the electromagnetic measurements.

An electromagnetic measurement tool for making multi-frequency, full tensor, complex, electromagnetic measurements includes a triaxial transmitter and a triaxial receiver deployed on a tubular member. An electronic module is configured to obtain electromagnetic measurements at four or more distinct frequencies. The measurement tool may be used for various applications including obtaining a resistivity of sand layers in an alternating shale-sand formation; computing a dielectric permittivity, a conductivity anisotropy, and/or a permittivity anisotropy of a formation sample; and/or identifying formation mineralization including discriminating between pyrite and graphite inclusions and/or computing weight percent graphite and/or pyrite in the formation sample.

Multi-frequency electromagnetic tensor measurements

A method for determining a level of organic maturity of a shale gas formation includes inverting multifrequency complex conductivity data to estimate a volume fraction of graphite, turbostatic carbon nanostructures, and pyrite. The inversion is validated using estimates of the volume fraction of graphite, turbostatic carbon nanostructures, and pyrite. The volume fraction of graphite and turbostatic carbon nanostructures is correlated to a level of organic maturity log of the shale gas formation. The level of organic maturity log is validated using sulfur content obtained from pyrolysis or vitrinite reflectance. A variation of an electromagnetic response due to the volume fraction of graphite, turbostatic carbon nanostructures, and pyrite is quantified. The electromagnetic response is modified by removing the quantified variation to obtain resistivity and permittivity values.

Subsurface estimation of level of organic maturity

A method to estimate water saturation in electromagnetic measurements includes making an electromagnetic measurement and performing at least one of (a) creating an analytical forward model of the EM measurement, (b) creating a numerical finite difference forward model of the EM measurement, and (c) performing an inversion. The method also includes removing at least one petrophysically-adverse alteration of EM measurements in the frequency range from 1 Hz to 100 MHz. A petrophysically-adverse alteration is due to the presence of at least one of the following: pyrite, graphitic-precursors, magnetite, and other conductive minerals.

Method to estimate water saturation in electromagnetic measurements

A method for calibrating an electromagnetic core analysis tool is disclosed. The method includes disposing a tilted test loop inside of or outside of a tool having more than one antenna. A uniform test pack, a layered test pack, and an effective media test pack are each disposed in the tool. A signal is induced in a receiver antenna in the tool when a second antenna is energized with a known current of a known frequency. The induced signal is measured and a calibration gain and offset is determined. A corrected signal is produced and compared with the determined signal based on a forward model.

Growing community of inventors

Austin, TX, United States of America

Siddharth Misra