Schlumberger Technology Corporation

Nikita Valentinovich Seleznev

Tarek M Habashy

Austin Boyd

Denise E Freed

Mehdi Hizem

Chang-Yu Hou

Brian Oliver Clark

Robert L Kleinberg

Ridvan Akkurt

Kamilla Fellah

Michel Claverie

Mohammad-Reza Taherian

Bastien Fournie

The subject disclosure relates to a method for determining a volume fraction of water and water salinity in organic shales and other geological formations. The method includes a knowledge of complex formation permittivity at several frequencies and minimizes or excludes dependency on external parameters, such as the permittivity of the formation mineral phase.

Methods for determining a volume fraction of water and water salinity in organic shale reservoirs using multi-frequency dielectric well logging measurements

A permeability log is generated by running borehole tools in a borehole traversing a formation, including at least electromagnetic (EM) tool providing at least a low-frequency complex conductivity measurement at least one frequency. Data from the EM tool and other data obtained from other tools are provided to a wideband EM model, where a data inversion is conducted to provide a plurality of outputs from which a cementation exponent may be calculated. The cementation exponent is used to find a formation factor at each depth of interest in the borehole, and the formation factor is used to find a permeability value which is used for the permeability log. The permeability log may be generated without the use of core data.

Permeability determinations from wideband EM models using borehole logging tools

Techniques involve inverting a dielectric dispersion model based on the geometrical and electrochemical effects that affect dielectric dispersion in fluid-saturated rocks and other porous formation with formation data and measurements to obtain further formation characteristics. A workflow involves using multi-frequency dielectric measurements of the dielectric constant and the conductivity of the formation for reservoir evaluation. The workflow also involves determining formation data such as matrix permittivity, formation temperature, pressure, and porosity, etc., and inverting the formation data and the multi-frequency dielectric measurements with the dielectric dispersion model to determine formation characteristics such as volumetric fraction of water in the formation, the formation water salinity and the Cation Exchange Capacity (CEC), etc. From the CEC log, in combination with other measurements, clay typing may be performed and swelling clays may be identified.

Method of determining CEC and other properties from multi-frequency dielectric measurements

Methods and systems are provided for investigating a rock sample, in which wideband electromagnetic response data are obtained and processed by inversion in order to determine values for a plurality of parameters of the rock sample. The wideband electromagnetic response data is derived from electromagnetic measurements of the rock sample at frequencies that fall within a wideband of frequencies, wherein the wideband of frequencies includes a low frequency sub-band that is sensitive to conductivity of the rock sample and a high frequency sub-band that is sensitive to the permittivity of the rock sample. In one embodiment, the inversion can employ a wideband model that accounts for two different polarization mechanisms. The wideband model can be used to describe predicted electromagnetic response of the rock sample at frequencies that fall within the wideband of frequencies.

Evaluation of formation utilizing wideband electromagnetic measurements

A method for determining permittivity of a rock formation mineral matrix includes measuring a permittivity of a sample of the rock. A fractional volume of pore space in the sample is determined. A mixing law and a permittivity of a fluid filling the pore space are used to determine the permittivity of the formation mineral matrix from the measured permittivity.

Method and apparatus for determining permittivity of rock matrix

A method (and system) is provided that enhances production of hydrocarbons from a subterranean formation by identifying at least one target interval of the subterranean formation that is in proximity to a pay interval, wherein the at least one target interval has an electrical resistance less than electrical resistance of the pay interval. A plurality of electrodes are placed in positions spaced apart from one another and adjacent the at least one target interval. Electrical current is injected into the target interval by supplying electrical signals to the plurality of electrodes. The electrical current injected into the at least one target interval passes through at least a portion of the at least one target interval in order to heat the at least one target interval and heat the pay interval by thermal conduction for enhancement of production of hydrocarbons from the pay interval.

Electrical heating of oil shale and heavy oil formations

Formation wettability is quantifiably estimated from measurements of dielectric constant and conductivity. In particular, wettability state of formation rock in a subterranean environment is estimated from multi-frequency measurements of rock dielectric constant and conductivity. A dielectric dispersion model is used to invert the measurements and estimate the saturation exponent. The resulting saturation exponent is used to quantify wettability, e.g., by calculating a wettability index.

Determining formation wettability from dielectric measurements

A method for determining reservoir formation properties that consists of exciting the reservoir formation with an electromagnetic exciting field, measuring an electromagnetic signal produced by the electromagnetic exciting field in the reservoir formation, extracting from the measured electromagnetic signal a spectral complex resistivity as a function of frequency, fitting the spectral complex resistivity with an induced polarization model and deducing the reservoir formation properties from the fitting with the induced polarization model.

Applications of wideband EM measurements for determining reservoir formation properties

An apparatus for use in a system that includes a network analyzer for determining a property, such as dielectric permittivity of a sample material as a function of frequency, the apparatus including: a cylindrical chamber for receiving the sample; a coaxial connector having a first relatively small diameter end coupleable with the analyzer and a second relatively large diameter end communicating with a side of the cylindrical chamber, the connector having inner and outer coaxial conductors; the inner conductor of the connector having a diameter that tapers outwardly from the first end to the second end, and the outer conductor of the connector having an inner surface whose diameter tapers outwardly from the first end to the second end. The chamber can accommodate relatively large samples, such as standard earth formation coring samples.

Method and device for complex permittivity measurements as a function of frequency

Techniques for estimating the fraction of water in formations being investigated use measurements of dielectric permittivity at a number of frequencies. The techniques have the advantage of minimizing or eliminating external inputs that can introduce inaccuracies.

Method for determining properties of earth formations using dielectric permittivity measurements

Techniques for determining formation characteristics use measurements of dielectric permittivity at a number of frequencies. Determined characteristics include the vertical and horizontal formation dielectric constant and conductivity, the formation water conductivity, the water saturation, the cementation and the saturation exponents. In laminated formations these profiles can be determined for each lamina. Also, formation dielectric properties are used in determination of the rock type.

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Cambridge, MA, United States of America

Nikita Valentinovich Seleznev