Schlumberger Technology Corporation

Barbara I Anderson

Reza Taherian

Thomas D Barber

Martin G Luling

Emmanuel Legendre

Pabitra N Sen

Francois M Auzerais

Elizabeth B Dussan V

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 &#x2208;can be obtained. The electromagnetic measurement data also includes measurements at different frequencies from which values for frequency-dependent dielectric permittivity &#x2208;(f) can be obtained. Using these measurements, the frequency-dependent spectrum of the sample may be determined.

Methods for determining dielectric permittivity spectrum of underground rock formations

A method for determining the frequency-dependent dielectric permittivity spectrum of a rock sample, comprising:&#x2014;defining a series of electromagnetic measurement data comprising at least a first measurement at a frequency from which a substantially frequency-independent value of dielectric permittivity &#x2208;, can be obtained; and at least second and third measurements at different frequencies from which values for frequency-dependent dielectric permittivity &#x2208;(f) can be obtained; and&#x2014;using the first, second and third measurements to determine the frequency-dependent spectrum of the sample.

A method for determining spatial distribution of fluid injected into a subsurface rock formation includes injecting the fluid into the rock formation. The fluid includes therein electrically conductive solid particles dispersed in an electrolyte. An electromagnetic response of the formation is measured. The measured electromagnetic response is used to determine spatial distribution of the injected fluid.

Method for determining spatial distribution of fluid injected into subsurface rock formations

Characteristics of invasion profiles exhibiting effects of gravity, and particularly their manifestations on resistivity logs of a plurality of different radial depths of investigation, are used to determine formation characteristics, including vertical permeability. One embodiment includes the following steps: suspending a logging tool in the borehole; producing a plurality of resistivity measurements, having respectively different radial depths of investigation, as the logging device is moved through the borehole, to obtain a plurality of resistivity logs; determining the presence of a buoyancy marker in the resistivity logs in a formation bed invaded with filtrate from the drilling mud, and the extent of the buoyancy marker; and determining permeability of the formations as a function of the extent of the buoyancy marker.

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Brookfield Center, CT, United States of America

Barbara I Anderson