Patents by Inventor Keh-Jim Dunn

Keh-Jim Dunn has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Publication number: 20100138157
    Abstract: A computer-implemented method and system for processing subsurface logs to enhance the continuity of physical property measurements. The method includes obtaining a set of measurement signals along a spatial or time domain from at least one sensor tool moving through a borehole which has traversed through a subsurface region. The method additionally includes performing a global inversion of the set of measurement signals along the spatial or time domain to determine a set of physical properties of the subsurface region having a smooth variation along the spatial or time domain, wherein the set of physical properties can be utilized to determine characteristics of the subsurface region.
    Type: Application
    Filed: December 1, 2008
    Publication date: June 3, 2010
    Inventors: Boqin Sun, Keh-Jim Dunn
  • Patent number: 6937014
    Abstract: The present invention provides a method for obtaining a multi-dimensional proton density distribution from a system of nuclear spins. A plurality of nuclear magnetic resonance (NMR) data is acquired from a fluid containing porous medium having a system of nuclear spins. A multi-dimensional inversion is performed on the plurality of nuclear magnetic resonance data using an inversion algorithm to solve a mathematical problem employing a single composite kernel to arrive at a multi-dimensional proton density distribution. Ideally, the mathematical problem can be cast in the form of a Fredholm integral of the first kind wherein a two or more kernels can be reduced to a single composite kernel for ease of solution. Preferably, a series of conventional CPMG pulse sequences, using a conventional NMR tool, can be used to excite the system of nuclear spins.
    Type: Grant
    Filed: March 24, 2003
    Date of Patent: August 30, 2005
    Assignee: Chevron U.S.A. Inc.
    Inventors: Boqin Sun, Keh-Jim Dunn
  • Patent number: 6833698
    Abstract: Novel pulse sequences are used to probe the properties of porous media, such as are found in subterranean formations and core samples. This use allows diffusion effects to be uncoupled from the overall T2 relaxation time of the sample. Properties such as internal field gradient and distribution of diffusion coefficients may be determined. A series of pulse sequences are applied to the media to be evaluated. The series of pulse sequences include first and second windows. The first windows include pulse sequences have varying characteristics, such as increasing echo spacing, while the second windows preferably utilize similar pulse sequences which have very small echo spacing. Apparent internal field gradient distribution and apparent diffusion coefficient may be determined as a function of T2 relaxation time.
    Type: Grant
    Filed: May 15, 2002
    Date of Patent: December 21, 2004
    Assignee: ChevronTexaco U.S.A. Inc.
    Inventors: Boqin Sun, Keh-Jim Dunn
  • Publication number: 20040189296
    Abstract: The present invention provides a method for obtaining a multi-dimensional proton density distribution from a system of nuclear spins. A plurality of nuclear magnetic resonance (NMR) data is acquired from a fluid containing porous medium having a system of nuclear spins. A multi-dimensional inversion is performed on the plurality of nuclear magnetic resonance data using an inversion algorithm to solve a mathematical problem employing a single composite kernel to arrive at a multi-dimensional proton density distribution. Ideally, the mathematical problem can be cast in the form of a Fredholm integral of the first kind wherein a two or more kernels can be reduced to a single composite kernel for ease of solution. Preferably, a series of conventional CPMG pulse sequences, using a conventional NMR tool, can be used to excite the system of nuclear spins.
    Type: Application
    Filed: March 24, 2003
    Publication date: September 30, 2004
    Applicant: Chevron U.S.A. Inc.
    Inventors: Boqin Sun, Keh-Jim Dunn
  • Publication number: 20030214287
    Abstract: Novel pulse sequences are used to probe the properties of porous media, such as are found in subterranean formations and core samples. This use allows diffusion effects to be uncoupled from the overall T2 relaxation time of the sample. Properties such as internal field gradient and distribution of diffusion coefficients may be determined. A series of pulse sequences are applied to the media to be evaluated. The series of pulse sequences include first and second windows. The first windows include pulse sequences have varying characteristics, such as increasing echo spacing, while the second windows preferably utilize similar pulse sequences which have very small echo spacing. Apparent internal field gradient distribution and apparent diffusion coefficient may be determined as a function of T2 relaxation time.
    Type: Application
    Filed: May 15, 2002
    Publication date: November 20, 2003
    Inventors: Boqin Sun, Keh-Jim Dunn
  • Patent number: 4715711
    Abstract: The present invention is a high-pressure sapphire cell designed to measure the properties of a petroleum reservoir fluid sample. It comprises at least two sapphire anvils, a pressure vessel having inlet and outlet parts, gaskets between the anvils and the pressure vessel; and a means for forcing the anvils together to form a fluid-tight seal between the anvils and the pressure vessel. Once a fluid sample enters the pressure vessel, a high pressure environment similar to a petroleum reservoir is created by an outside pressure pump via a pressure inlet tube. It is in this state that the fluid measurements are made on the sample.
    Type: Grant
    Filed: February 4, 1987
    Date of Patent: December 29, 1987
    Assignee: Chevron Research Company
    Inventor: Keh-Jim Dunn