Core Laboratories, Inc.

Western Atlas International, Inc.

Harold T Barnaby

A core holder is provided for making petrophysical measurements of core samples from a borehole. The core holder is designed to make resistivity measurements and fluid-flow tests under reproduced conditions of in-situ fluid saturation, reservoir pressure and reservoir temperature.

Apparatus for measuring the resistivity of a sample

A mercury pump for analyzing geological core samples has a vertically oriented cylindrical cavity in which a lower portion forms a mercury displacement chamber and an upper portion in axial alignment with it forms a sample chamber. A pressure transducer, e.g., a strain gauge or solid-state sensor, in communication with the sample chamber produces an electrical pressure signal. A screw ball jack urges a synthetic-resin piston upwards in the displacement section to push the mercury into the sample chamber. The displacement of the mercury is sensed by an electronic encoder coupled to the hand crank of the jack, and provides data regarding both the direction and the amount of piston displacement. A microprocessor-controlled volume-measuring device has inputs connected to the encoder, and automatically provides core sample data, in response to the signals from the encoder, at the end of a core test run.

Mercury pump

Compressibility test apparatus and method of testing compressibility. The apparatus includes a holder having a sample chamber for holding a sample in the environment of a confining pressure and means for supplying an internal pressure to the held sample. The sample and various conduits and channels that communicate with the sample define an internal system volume. Connected in this internal system volume is an internal volume adjustment pump that is operable to vary the internal system volume in incremental steps, by which the internal pressure is reduced (or increased) in steps to increase (or reduce) the net confining pressure. As a result, changes in the sample volume as a function of changes in the net confining pressure are determined, from which the compressibility of the sample is obtained.

Method and apparatus for testing the compressibility of subterranean

A viscosimeter measures the viscosity of a fluid, such as a petroleum hydrocarbon liquid, by driving a capillary through the fluid and measuring the pressure drop across the capillary. The viscosimeter comprises a pressure cylinder, a piston within the cylinder having at least one capillary tube, and an arrangement for driving the piston at a known speed so that the fluid is displaced at a known volumetric rate through the capillary tube. Pressure sensors on either end of the cylinder measure the capillary pressure drop. In a preferred embodiment, the piston has a main body and a selector plate. The main body has a plurality of capillary tubes each of a different bore size, and the selector plate is rotatable relative to the main body by rotating a selector handle outside the cylinder. An oven enclosure permits the cylinder, and its fill of fluid, to be heated in an air bath to reservoir temperatures.

Driven-capillary viscosimeter

A core holder is used in the nonsteady-state testing of permeability and other flow characteristics of a geological core sample. A reference pressure reservoir assembly contains a predetermined volume of test gas at a known pressure, and a gas operated valve admits this test gas rapidly to the upstream end of the core sample. The downstream end of the core sample is open to the atmosphere, and the pressure in the reference pressure reservoir assembly is monitored as it decays in time while the test gas passes through the core sample. The gas-operated valve is formed of an upstream plug, a gland fitting the plug, and a valve stem fitting into a generally cylindrical cavity formed in the plug and gland. The valve stem has an enlarged head at one end with an annular slot on a cylindrical surface thereof. This structure minimizes turbulence in the flow of the test gas through the valve assembly.

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Duncanville, TX, United States of America

Harold T Barnaby