Schlumberger Technology Corporation

Prad Research and Development Nv

Services Petroliers Schlumberger

Schlumberger Holdings Limited

Prad Research and Development Limited

Services Petroliers Schlumberger Sa

Schlumberger Oilfield Assistance Limited

Philip S Cheung

Andrew J Hayman

Dennis J Pittman

Tarek M Habashy

Dzevat Omeragic

Tianhua Zhang

Roel Van Os

Yong-Hua Chen

Dominique Dion

Patrick P Vessereau

Abdurrahman Sezginer

Richard Bloemenkamp

Jean-Pierre R Delhomme

Michel V Berard

Daniel Codazzi

Gilles Mathieu

Yinyu Wang

Hsui-lin Liu

Herve Chappellat

Methods and systems for obtaining an electrical impedivity and/or resistivity image of a subterranean formation are provided. The electrical impedivity and/or resistivity image can be obtained by determining first formation impedivity data and second formation impedivity data. The first formation impedivity data can be based on a component of the measured impedance data orthogonal a downhole fluid impedance. The second formation impedivity data can be based on an amplitude of the measured impedance data. A combined formation impedivity data can be obtained by combining a portion of the first formation impedivity data based on a first formation impedivity determination process with a portion of the second formation impedivity data based on a second formation impedivity determination process. The electrical impedivity and/or resistivity image of the subterranean formation can then be obtained by using the combined formation impedivity data.

Methods and systems for obtaining an electrical impedivity and/or resistivity image of a subterranean formation

A system and method for imaging properties of subterranean formations in a wellbore is provided. The system comprises a formation sensor for collecting currents injected into the subterranean formations, the formation sensor positionable on a downhole tool deployable into the wellbore. The system comprises a controller for controlling the formation sensor and a formation imaging unit. The formation imaging unit comprises a current management unit for collecting data from the currents injected into the subterranean formations, the currents having at least two different frequencies. The formation imaging unit comprises a drilling mud data unit for determining at least one drilling mud parameter, a formation data unit for determining at least one formation parameter from the collected data, and an inversion unit for determining at least one formation property by inverting the at least one formation parameter.

System and method for imaging properties of subterranean formations

A method, a system, and an apparatus are described for the data acquisition in the well-logging of a borehole wall during the investigation of formation properties. Data acquisition is conducted by either an adaptive phase compensation processing or a modulus mode processing, both of which use in-phase and out-of-phase current components to obtain current values. Adaptive phase compensation employs a calculation of a phase shift compensation value, which may then be applied to subsequent acquisitions and can be further processed in the generation of an image of the borehole wall.

Systems and methods for investigating a formation surrounding a borehole

A fluid sensor (and method) for determining at least one parameter of a fluid of a wellbore is provided. The fluid sensor has a base positionable in the wellbore, a base electrode operatively positionable in the insulation, and a raised electrode having at least one base portion and at least one raised portion. The base comprises insulation. The base portion is operatively positionable in the insulation. The at least one raised portion is positionable a distance above the base electrode such that a space is defined therebetween for the passage of the wellbore fluid therethrough. A voltage is applied across the base electrode and the raised electrode to generate a current therebetween whereby at least one parameter of the wellbore fluid may be determined. The fluid sensor is deployable into the wellbore via the downhole tool.

Fluid sensor and method of using same

Methods and devices for determining a rate of penetration and/or rate of rotation for a drilling assembly or logging tool while drilling or logging a wellbore are provided. The methods can include the steps of: at respective first and second time instant, acquiring and storing a first logging data frame using a first array of sensors and a second logging data frame using a second array of sensors where wherein the logging data relate to at least one property of a zone surrounding the wellbore and the second logging data frame overlaps at least partially the first logging data frame;comparing the first and second logging data frames;determining a relative change in depth and/or azimuth between the first and second logging data frames; andcalculating the rate of penetration and/or rate of rotation based on the relative change in depth and/or azimuth determined and a difference between the first and second time instants.

Device and method of determining rate of penetration and rate of rotation

A method of correcting accelerometer and magnetometer measurements made in a well is provided. The method includes making a series of triaxial measurements with magnetometers and accelerometers in an interval of the well to derive measured values of gravitational acceleration g, magnetic filed intensity B, and the sine of the magnetic inclination sin I. The method also includes obtaining known values of g, B and sin I for the interval and determining values of a correction to be applied to the measured values by simultaneously minimizing the difference between the measured values and the known values of g, B and sin I for the interval. The method also includes applying the correction to the measured values to obtain in situ corrected values for g, B and sin I.

Methods of correcting accelerometer and magnetometer measurements

A method of measuring depth and/or azimuth of logging data, the logging data being related to at least one property of a zone GF, CS, CA surrounding a wellbore and being measured by at least a sensor array SAD, SAD, the method comprising the steps of:

Device and method of measuring depth and azimuth

Apparatus for obtaining images of the wall of a borehole, comprises a tool body; a light source mounted on the tool body and arranged to illuminate the borehole wall; a camera mounted in the tool body; and a mirror moveably mounted on the tool body and spaced axially from the camera and arranged to reflect an image of the borehole wall at the camera, wherein the movement of the mirror allows images of different parts of the borehole wall to be reflected at the camera.

Apparatus and method for obtaining images of a borehole

Apparatus for imaging the wall of a borehole drilled through an underground formation, comprising: a light source; an optical detector device such as a CCD camera; a sensor head including a window for application against the wall of the borehole, the light source being connected to the sensor head so as to illuminate the region of the borehole wall when the sensor head is applied to the wall; and an optical fiber bundle connecting the window to the optical detector device so as to pass optical signals from the wall to the optical detector device; wherein the optical fiber bundle comprises a coherent bundle, each fiber of the coherent bundle providing one pixel of a two-dimensional, multi-pixel image of the borehole wall.

Borehole imaging

A method for depth matching borehole images and/or core section images is disclosed wherein signals from sensors at different levels on a logging tool are converted into an averaged signal representing the average bed signal at the center of the borehole at each of the different levels. A depth matching technique is applied to the averaged signals from the sensors at different levels on the logging tool to determine the optimum depth offset necessary for matching two sets of signals from sensors at the different levels of the logging tool. In an alternative embodiment of the invention a Hough transform is utilized to process the well log images and generate three-dimensional images in Hough space. The three dimensional images are converted into two-dimensional extremum curves. Depth matching is performed on the two dimensional extremum curves to calculate an offset to match the two dimensional extremum curves. The calculated offset is then applied to the well log images to depth match them.

Method and apparatus for improved depth matching of borehole images or core images

The invention concerns an apparatus for investigating the wall of a borehole tilled with non-conductive mud, said apparatus comprising: a pad having an inside face and an outside face for pressing against the wall of the borehole; a set of measurement electrodes mounted on the outside face of the pad, potentials differences being measured between said measurement electrodes in order to provide measured points representative of the resistivity of the formation; both a source electrode and a return electrode adapted to inject current into the formation, the set of measurement electrodes being situated between the source electrode and the return electrode.

Method and apparatus for imaging earth formation

A resistivity tool for investigating a wall of a borehole drilled with a non-conductive mud includes a tool body adapted to be incorporated in a logging-while-drilling tool assembly; a resistivity sensor disposed on the tool body, wherein the resistivity sensor comprises a sensor pad supporting a current injector electrode, a current return electrode, and an array of measurement electrodes, and a circuitry for controlling current injection from the current injector electrode and for measuring voltage difference between electrodes in the array of measurement electrodes, wherein the current injector electrode and the current return electrode are disposed near opposite ends of the sensor pad and the array of measurement electrodes is disposed between the current injector electrode and the current return electrode, wherein the sensor pad is constructed of an insulating material and includes a conductive shielding member, or wherein the sensor pad is constructed of a conducting material and includes insulating sections around the electrodes.

Growing community of inventors

Montesson, France

Philip S Cheung