Shell Oil Comapny

Monroe H Waxman

Harold J Vinegar

Philip J Closmann

Peter Vanmeurs

Charles T Deeds

Logging means and methods are disclosed for distinguishing between dispersed and laminated clay in earth formations. A wireline apparatus is employed consisting of a multifrequency induced polarization logging tool operating at extremely low frequencies, combined with other logging tools which measure the total amount of clay in the formation. A determination is then made of the fraction of the total clay content in the formation which is due to laminated clay.

Induced polarization method and apparatus for distinguishing dispersed

An in-situ method of determining the pore size distribution, capillary pressure curve, and permeability of a formation using induced polarization logging measurements. The induced polarization (IP) voltage decay curve is measured opposite the formation of interest and the voltage decay curve is decomposed into a series of relaxation times related to the pore size distribution. The capillary pressure curve and the permeability are approximated from the pore size distribution. The measurements can also be made in the frequency domain using various frequencies to obtain the variation in phase shift with frequency. The variation in phase shift with frequency can be correlated with previous core measurements to obtain the pore size distribution, capillary pressure curve and formation permeability.

In-situ induced polarization method for determining formation

The stimulus signal for an induced polarization logging system is presented to the formation intermittently, alternately being applied and removed as a square wave of alternating polarity, and the response signal amplification level is time gated with the stimulus signal.

Time-domain induced polarization logging method and apparatus with gated

An induced polarization tool using focused electrodes that uses direct coupling in the focusing loop to prevent spurious phase shifts. The invention uses a differential-in differential-out amplifier and voltage-controlled resistances to provide zero potential difference between pairs of monitoring electrodes. The measured current and voltage are digitized downhole and transmitted to the surface. At the surface means are provided for determining in-phase and quadrature response.

Method for induced polarization logging

In-situ method for determining pore size distribution, capillary

An oil and water-containing subterranean reservoir can be heated in a manner capable of inducing an economically feasible production of oil from zones which were initially so impermeable as to be undesirably unproductive in response to injections of oil recovery fluids. Treatment zones of specified thickness are conductively heated from boreholes arranged in a specified pattern of heat-injecting and fluid-producing wells and heated to above about 600.degree. C.

In-situ steam drive oil recovery process

Apparatus for focused electrode induced polarization logging

Viscous asphaltenic crude oils are converted to pumpable liquid oil products in field locations by precipitating and separating asphaltenes, then mildly thermally converting the asphaltenes to mobile asphaltene-conversion products that can be mixed with at least the maltene components of the crude oils to form the pumpable liquid oil products.

Process for separating and converting heavy oil asphaltenes in a field

An apparatus is disclosed for borehole measurements of the induced polarization of earth formations. The apparatus consists of an induced polarization logger capable of measuring both in-phase and quadrature conductivities in the frequency domain. A method is described which uses these measurements to determine cation exchange capacity per unit pore volume, Q.sub.v, brine conductivity, C.sub.w, and oil and water saturations, S.sub.o and S.sub.w, in shaly sands.

Growing community of inventors

Houston, TX, United States of America

Monroe H Waxman