Patents Represented by Attorney, Agent or Law Firm Keith G. W. Smith
  • Patent number: 5852363
    Abstract: A method and apparatus for determining the geometrical characteristics of a well, including insertion of a sonde of elongate shape into the well, the sonde including azimuth electrodes (A.sub.azi), an annular current electrode (A.sub.0), and at least one annular current return electrode (A). The annular current electrode (A.sub.0) emits a current I.sub.0, which flows essentially in a column of mud situated inside the well and returns to the annular current return electrodes. Signals are induced in response to the current I.sub.0 from which can be determined the geometrical characteristics of the well. Alternative embodiments include an apparatus which is symmetrical about the azimuth electrodes. High resolution measurements are obtained by computed focusing. In a first effective operating mode, currents i.sub.1 and i'.sub.1 are emitted from guard electrodes A.sub.1 and A'.sub.1 located on either side of the current electrode (A.sub.0,A'.sub.0), the current I.sub.
    Type: Grant
    Filed: October 18, 1996
    Date of Patent: December 22, 1998
    Assignee: Schlumberger Technology Corporation
    Inventor: Jan W. Smits
  • Patent number: 5841131
    Abstract: A fiber optic pressure transducer having enhanced resolution and dynamic range includes a fiber optic core having one or more gratings written onto it, a birefringence structure for enhancing the birefringence of the core, and a structure for converting isotropic pressure forces to anisotropic forces on the fiber core. Several different embodiments of prestressing structure are disclosed (both extrinsic and intrinsic). Several different embodiments of structure (both extrinsic and intrinsic) for converting isotropic pressure to anisotropic pressure are also disclosed. The fiber optic pressure transducer according to the invention is advantageously used in conjunction with a light source and a spectral demodulation system in order to detect pressure ambient to the fiber optic pressure transducer based on the wavelength and shift of spectral peaks.
    Type: Grant
    Filed: July 7, 1997
    Date of Patent: November 24, 1998
    Assignee: Schlumberger Technology Corporation
    Inventors: Robert J. Schroeder, Eric Udd
  • Patent number: 5831743
    Abstract: After an oil well has been drilled, lined and cased, and is producing, it may be desirable in situ (either at the wellhead or downhole) to measure, and log (record), the rate at which fluid, and its several distinct components, is flowing out of the geological formations through which the bore has been drilled and is passing into and up the casing. A useful type of detector system for this purpose is an optical probe (31), and the invention proposes a novel design of probe which has a doubly-angled tip, there being measured the light totally internally reflected at the interface (37), which depends on the ratio of the refractive indices of the probe tip and fluid component in which it is immersed.
    Type: Grant
    Filed: February 6, 1997
    Date of Patent: November 3, 1998
    Assignee: Schlumberger Technology Corporation
    Inventors: Rogerio Tadeu Ramos, Edmund J. Fordham
  • Patent number: 5832409
    Abstract: An automated gas permeameter measures permeabilities of porous samples, such as rocks, ranging from 0.1 milliDarcys to 10 Darcys within 0.5% under dry and humid conditions. The automated gas permeameter includes a program for estimating a coarse permeablity value. The program uses the coarse value to determine settling time for pressure to reach steady state within 0.1% and optimal operating conditions, such as the setting of mass flow rates imposed on the sample. Operating conditions of the permeameter are set by the program according to the resolution and range of flow controllers, accuracy of a pressure transducer, and the limit of applicability of Darcy's law for a sample.
    Type: Grant
    Filed: April 25, 1997
    Date of Patent: November 3, 1998
    Assignee: Schlumberger Technology Corporation
    Inventors: T. S. Ramakrishnan, Sandeep Dhawan, Alphonse Cappiello
  • Patent number: 5809163
    Abstract: A method of characterizing texture heterogeneities in a geological formation traversed by a borehole. The method records an image of the borehole wall such as that provided by Schlumberger's Formation Microscanner (FMS) apparatus, representative of variations in a physical parameter of the formation in the longitudinal direction of the borehole and around the periphery of the wall. Geological objects are extracted from the image corresponding to a determined morphological type of heterogeneity. The variation in at least one attribute defined for this type of heterogeneity in the longitudinal direction of the borehole is determined. The invention is particularly applicable to vug detection.
    Type: Grant
    Filed: February 16, 1995
    Date of Patent: September 15, 1998
    Assignee: Schlumberger Technology Corporation
    Inventors: Jean-Pierre Delhomme, Jean-Fran.cedilla.ois Rivest
  • Patent number: 5808963
    Abstract: Parametric inversion is used to advantage in a technique and apparatus for borehole logging to determine properties of anisotropic formations, and a dispersion function that varies with frequency is used in the modeling of the formations.
    Type: Grant
    Filed: January 29, 1997
    Date of Patent: September 15, 1998
    Assignee: Schlumberger Technology Corporation
    Inventor: Cengiz Esmersoy
  • Patent number: 5796252
    Abstract: A nuclear magnetic resonance (NMR) logging technique reveals the volume of hydrocarbons in an earth formation. The differences in viscosity among gas, oil and water are used to distinguish among these three fluids. During NMR logging, a parameter of a sequence of magnetic field pulses is altered, causing echo signal strengths to vary due to the diffusion of the fluids in the formation. The volume of hydrocarbons in the formation is determined from detected spin echo strengths. The invention applies to wireline NMR logging and NMR logging-while-drilling techniques.
    Type: Grant
    Filed: January 15, 1997
    Date of Patent: August 18, 1998
    Assignee: Schlumberger Technology Corporation
    Inventors: Robert L. Kleinberg, Lawrence L. Latour, Abdurrahman Sezginer
  • Patent number: 5789669
    Abstract: A method is disclosed for determining true formation pressure in formations surrounding a fluid-containing borehole having a mudcake on the surface thereof, including the following steps: with the pressure in the borehole at a first measured borehole pressure, measuring, as a first probe pressure, the pressure in the formation adjacent the mudcake; with the pressure in the borehole at a second measured borehole pressure, measuring, as a second probe pressure, the pressure in the formation adjacent the mudcake; and deriving the true formation pressure from the first and second measured borehole pressures and the first and second probe pressures.
    Type: Grant
    Filed: August 13, 1997
    Date of Patent: August 4, 1998
    Inventor: Charles Flaum
  • Patent number: 5790185
    Abstract: A video logging tool is described which is particularly well adapted for production logging of oil or gas wells. The tool has both an end view optical system and a side view optical system for imaging side and end view on a CCD array in a camera.
    Type: Grant
    Filed: December 6, 1996
    Date of Patent: August 4, 1998
    Inventors: Fran.cedilla.ois Auzerais, Robert J. Schroeder, Benoit Couet, Jeffrey A. Tarvin
  • Patent number: 5786595
    Abstract: A method for determining total clay content of an earth formation based on elemental concentration logs obtained from a logging tool. This method avoids the need for obtaining an aluminum concentration measurement. First, the concentrations of a plurality of elements in the formation are determined without measuring an aluminum concentration. Then, at least the silicon, calcium, and iron concentrations are combined in accordance with a function determined by regression analysis to produce an estimate of the total clay content.
    Type: Grant
    Filed: March 29, 1996
    Date of Patent: July 28, 1998
    Assignee: Schlumberger Technology Corporation
    Inventors: Susan L. Herron, Michael M. Herron
  • Patent number: 5767674
    Abstract: The instruments of a pulsed nuclear magnetic resonance device are included in a drill collar for evaluating earth formations. The resulting tool makes NMR measurements through an electrically non-conductive shield while the formation is being drilled.
    Type: Grant
    Filed: April 17, 1996
    Date of Patent: June 16, 1998
    Inventors: Douglas D. Griffin, James Stephen Hall, Abdurrahman Sezginer
  • Patent number: 5767680
    Abstract: Inception of hydrocarbon extraction from a reservoir causes the oil-water interface to warp and cusp toward the extraction gates along a well. This invention proposes time-lapse DC/AC measurements with an array of permanently deployed sensors in order to detect and estimate the change in geometry and proximity of the oil-water interface as a result of production, and therefore as a function of time. The estimation is carried out with a parametric inversion technique whereby the shape of the oil-water interface is assumed to take the form of a three-dimensional surface describable with only a few unknown parameters. A nonlinear optimization technique is used to search for the unknown parameters such that the differences between the measured data and the numerically simulated data are minimized in a least-squares fashion with concomitant hard bound physical constraints on the unknowns.
    Type: Grant
    Filed: June 11, 1996
    Date of Patent: June 16, 1998
    Assignee: Schlumberger Technology Corporation
    Inventors: Carlos Torres-Verdin, Sheng Fang, Vladimir Druskin, Ian Bryant, Metin Karakas
  • Patent number: 5754050
    Abstract: A method and apparatus for evaluating the geometrical characteristics of a well, comprising insertion of a sonde (12) of elongate shape into the well, the sonde including azimuth electrodes (A.sub.azi), an annular current electrode (A.sub.0), and at least one annular current return electrode (A). The annular current electrode (A.sub.0) emits a current I.sub.0, which flows essentially in a column of mud situated inside the well and returns to the annular current return electrodes. Signals induced in response to the current I.sub.0 are measured by the azimuth electrodes from which can be determined the geometrical characteristics of the well. An alternative embodiment includes an apparatus which is symmetrical about the azimuth electrodes.
    Type: Grant
    Filed: October 18, 1996
    Date of Patent: May 19, 1998
    Assignee: Schlumberger Technology Corporation
    Inventors: Jan W. Smits, Jean Claude Trouiller
  • Patent number: 5745436
    Abstract: A semi-dry marine seismic streamer cable (5) consists of a number of connected streamer cable sections (5a) which each comprises a mechanical jacket (10) surrounding a hollow core (11) enclosing seismic sensor (15) and signal transfer (16) means. Elongated axial stress elements (18) for transmitting axial loads and a radial reinforcement member (12) for relieving radial loads are provided in the jacket (10). The core (11) is filled with a fluid or a fluid-saturated foam and the sensor means (15) are mounted in the core (11) by vibration isolating elements (14).
    Type: Grant
    Filed: December 10, 1996
    Date of Patent: April 28, 1998
    Assignee: Geco A.S.
    Inventor: Simon Hastings Bittleston
  • Patent number: 5741707
    Abstract: 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.
    Type: Grant
    Filed: June 24, 1994
    Date of Patent: April 21, 1998
    Assignee: Schlumberger Technology Corporation
    Inventors: Michael M. Herron, Abigail Matteson, Michael Supp
  • Patent number: 5737220
    Abstract: A method of determining the elastic moduli of anisotropic earth strata uses acoustic and density data without making simplifying approximations of the Christoffel relation or the assumption of weak anisotropy. To this end, the relation is converted algebraically into a linear system and solved analytically to generate a solution for estimating elastic moduli. Preferably, a set of qP phase points obtained from walkaway VSP data, with multiple vertical angles, plus at least one vertical SV point, are used to derive the elastic moduli A.sub.11, A.sub.13, A.sub.33, A.sub.55. In the case of FTIV or other orthorhombic media, the method may also be applied to obtain additional elastic moduli.
    Type: Grant
    Filed: December 5, 1995
    Date of Patent: April 7, 1998
    Assignee: Schlumberger Technology Corporation
    Inventor: Douglas E. Miller
  • Patent number: 5717169
    Abstract: An improved technique for determining the thickness of a member, especially pipe such as fluid-filled casing in an earth borehole, includes the following steps: directing a pulse of ultra-sonic energy toward the inner surface of the pipe and receiving/storing, as a function of time, signals representative of ultra-sonic energy reflected from the inner surface of the pipe; determining, from the stored signals, the arrival or the initial echo from the inner surface; determining from the stored signals, the arrival and the amplitude of a first candidate initial echo from the outer surface of the pipe; performing a reverse search on the stored signals to determine, from stored signals at times earlier than the arrival time of the first candidate the arrival and the amplitude of a second candidate initial echo from the outer surface; comparing amplitudes of the first and second candidates and selecting, based on the comparison, one of the first and second candidates as the actual outer surface echo; and determinin
    Type: Grant
    Filed: August 26, 1996
    Date of Patent: February 10, 1998
    Assignee: Schlumberger Technology Corporation
    Inventors: Kenneth K. Liang, Philippe G. Herve, Fred E. Stanke
  • Patent number: 5711900
    Abstract: A tracer solution suitable for use in measuring flow velocities in a borehole, includes: a) a gadolinium salt of a carboxylic acid of general formula ##STR1## where R is an alkyl of not less than four carbon atoms, typically C4 or C5 alkyl, and R.sub.1 and R.sub.2 are hydrogen or an alkyl group, typically hydrogen, methyl or ethyl; b) a free branched-chain carboxylic acid such as an excess of the acid used to form the Gd salt; and c) a non-polar solvent such as hexane or heptane. The Gd content of the solution should be not less than about 50 g/l and is best when it is as high as possible, for example greater than 100 g/l, and the viscosity should be less than 20 cP.
    Type: Grant
    Filed: November 29, 1995
    Date of Patent: January 27, 1998
    Assignee: Schlumberger Technology Corporation
    Inventor: Timothy G. J. Jones
  • Patent number: 5689540
    Abstract: An x-ray generator provides a continuous bremsstrahlung photon spectrum for determining the water to liquid ratio in a mixture of oil/water/gas flowing through a pipe located a distance from the generator. A plurality of detectors measure photons passing along a beam path from the generator through the fluid. A detector is also provided to monitor the energy distribution of the generator. A time interval for measuring the output of each detector is established such that small changes in the gas to liquid ratio occur during this interval. An energy bin width is selected to provide a linear approximation of the water to liquid ratio. After binning the counts for each detector, a multi-phase flow characteristic such as the water to liquid fraction, liquid density, or liquid fraction along the beam path is determined.
    Type: Grant
    Filed: October 11, 1996
    Date of Patent: November 18, 1997
    Assignee: Schlumberger Technology Corporation
    Inventors: Kenneth E. Stephenson, Arthur J. Becker
  • Patent number: 5687138
    Abstract: A method of analyzing Stoneley waveforms obtained in a well logging operation, includes analyzing the waveforms by means of multiparameter inversion using one or more externally provided parameters to obtain borehole fluid slowness and borehole fluid attenuation, and analyzing the Stoneley waveforms by multiparameter inversion using the borehole fluid slowness and borehole fluid attenuation and the externally provided parameters so as to determine a parameter, such as mobility, related to permeability of the formation being logged. Complex conjugate back propagation using a maximum likelihood/least mean squares error estimator or by applying Prony's method and fitting model-derived dispersion curves can be used to obtain mobility.
    Type: Grant
    Filed: October 3, 1995
    Date of Patent: November 11, 1997
    Assignee: Schlumberger Technology Corporation
    Inventors: Christopher V. Kimball, Pawel Lewicki