Schlumberger Technology Corporation

Other

Jayanth R Banavar

Gustav Edward Derkits, Jr

David Linton Johnson

Pabitra N Sen

Kambiz A Safinya

William E Kenyon

Darryl D Coon

Sidney Robert Nagel

Paul L Baker

A method and apparatus for investigating earth formations surrounding a borehole operates by selectively heating a region of the formations, and measuring the thermal response to obtain useful information concerning the characteristic length scales of the pores in the heated region. The thermal response is obtained indirectly by measuring the electrical conductivity response. The invention can be utilized to obtain, inter alia, indications of porosity, permeability, and the distribution of pore geometries. In accordance with an embodiment of the method of the invention, the following steps are performed: heating a region of the formations with a series of pulses of microwave electromagnetic energy; measuring the conductivity characteristic of the region which result from the heating pulses; and determining a property of the region of the formations from the measured conductivity characteristic. In the preferred embodiment of the invention, the conductivity characteristic is converted to conductivity as a function of frequency, and the desired property is determined from the conductivity as a function of frequency. The disclosed technique can also be used for studying the microgeometry of media such as core samples.

Method and apparatus for measurement of the thermal behavior of porous

Well logging techniques are disclosed which use and/or measure formation textural parameters. A disclosed formation textural model is bimodal in nature, and includes fractions of spherical grains and of platey grains having a single aspect ratio. This model is used in obtaining improved well logging recordings.

Method and apparatus for obtaining properties of subsurface formations

A semiconductor memory device exhibiting non-volatile storage characteristics is disclosed. The device comprises a storage element, maintained in a prescribed range of temperatures, which exhibits an effect of charge storage and release of the stored charge upon application of a suitable bias voltage. Information is stored by exposure to light or by applying a suitable bias voltage to put the device into one of a multiplicity of long-lived states. In the case of exposure to light the state of the device is indicative of the integrated photon flux. Information can be stored or read out in times as short as 1 nanosecond or less and will remain stored for as long as 10.sup.5 seconds or longer without any sustaining voltage. A plurality of the memory devices can be interconnected in an array and can be used as a memory storage bank.

Non-volatile information storage arrays of cryogenic pin diodes

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Avon, CT, United States of America

Jayanth R Banavar