Schlumberger Technology Corporation

Michael G Supp

Bhavani Raghuraman

Ian D Bryant

Min-Yi Chen

Jose Navarro

Terizhandur S Ramakrishnan

Michael M Herron

Jagdish H Shah

Brindesh Dhruva

Aaron Jacobson

Fredrick A Jenet

Elizabeth B Dussan, V

Abigail Matteson

Stephane Pierre

Jennifer Trittschuh

Methods and apparatus are disclosed for measuring the permeability and/or porosity of ultra-low permeable rock samples. In some embodiments, the methods utilize fluid pressure perturbation.

Methods for measurement of ultra-low permeability and porosity

Methods are provided for measuring the permeability and/or porosity of a rock sample having an 'ultra-low' permeability while accounting for adsorption. The rock sample may be a sample obtained from a geological formation. The methods account for adsoption of gas within the rock samples.

Method for measurement of ultra-low permeability and porosity by accounting for adsorption

Apparatus and calibration methods are disclosed for measuring the permeability and/or porosity of ultra-low permeable rock samples. The apparatus uses a gas source, a sample chamber, chambers of calibrated volume, and pressure measurement devices.

Apparatus and calibration method for measurement of ultra-low permeability and porosity

Earth formations are characterized by using an array of electrodes which can measure streaming potentials in the formation, and by interpreting the data obtained by the electrodes. The electrodes are placed on a wireline tool, a LWD tool, or in a fixed manner about a completed wellbore. The measured streaming potentials are generated by drilling with an overbearing pressure, slitting the mudcake in a borehole, acid injection, or any of various other manners which causes fluid movement. The data obtained is interpreted to locate fractures, measure formation permeability, estimate formation pressure, monitor drilling fluid loss, detect abnormal pressure, etc. Particularly, a streaming potential voltage transient having a double peak profile signifies the presence of a formation fracture.

Apparatus for measuring streaming potentials and determining earth formation characteristics

Completion apparatus for measuring streaming potentials and determining earth formation characteristics

Methods for locating formation fractures and monitoring well completion using streaming potential transients information

While-drilling apparatus for measuring streaming potentials and determining earth formation characteristics

A method for determining formation fluid pressure in earth formation surrounding a borehole wall uses a downhole probe coupled to a variable-volume cavity. The probe is driven into contact with formation at the borehole wall. The method includes expanding the volume of the cavity during a first period of time to establish fluid communication between tool fluid and formation fluid, by withdrawing a minimal amount of fluid from the formation. During a second period of time the tool pressure is allowed to equilibrate to formation pressure. When pressure equilibrium is established, formation fluid pressure is set equal to tool pressure. A preferred embodiment includes terminating expanding the volume of the cavity on detecting a break in the mud cake seal. An associated formation pressure tester tool includes an elongated body; a probe defining a formation fluid inflow aperture, an electromechanical assembly defining a variable-volume cavity, a pretest flow line coupling the aperture to the cavity, a pressure sensor coupled to the cavity; and downhole electronic means for controlling the expansion of the volume of the cavity.

Determining the pressure of formation fluid in earth formations surrounding a borehole

Wireline apparatus for measuring steaming potentials and determining earth formation characteristics

A method and apparatus for analyzing a sample to determine its mineral composition. The invention combines X-ray diffraction with Fourier transform infrared spectroscopy to provide a complete spectrum including molecular vibrations, probed by FTIR scans and lattice spacing measured by X-ray diffraction in a single representation. This FX spectrum provides a more complete and accurate mineralogy than either of the techniques alone. In addition, new techniques for independent X-ray diffraction analysis and FTIR analysis are described.

Method for quantitative analysis of earth samples

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Middlebury, CT, United States of America

Michael G Supp