Patents by Inventor Caimu Tang

Caimu Tang 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).

  • Patent number: 9797242
    Abstract: A method for receiving an encoded integer includes acquiring a digitized waveform including a first plurality of pulses distributed among a second plurality of time slots, locating each of the pulses in the digitized waveform, computing a confidence value for each of the pulses, selecting a subset of the plurality of pulses, the subset including pulses having low confidence values computed, generating a set of unique waveforms corresponding to various combinations of the subset of pulses selected, computing a cross-correlation between each of the waveforms generated and the digitized waveform acquired, and selecting the waveform having the highest cross-correlation computed.
    Type: Grant
    Filed: May 16, 2014
    Date of Patent: October 24, 2017
    Assignee: SCHLUMBERGER TECHNOLOGY CORPORATION
    Inventors: Caimu Tang, Mark S. Beattie
  • Patent number: 9273517
    Abstract: A closed-loop method for geosteering includes acquiring logging while drilling data and processing the logging while drilling data downhole while drilling to obtain a geosteering correction (a correction to the drilling direction based upon the LWD measurements). The geosteering correction is further processed downhole to obtain new steering tool settings which are then applied to the steering tool to change the direction of drilling. These steps are typically repeated numerous times without the need for uphole processing or surface intervention.
    Type: Grant
    Filed: August 19, 2010
    Date of Patent: March 1, 2016
    Assignee: Schlumberger Technology Corporation
    Inventors: Borislav J. Tchakarov, Tsili Wang, Rodney S. Guenther, Thanh H. Cao, Caimu Tang
  • Publication number: 20140254322
    Abstract: A method for receiving an encoded integer includes acquiring a digitized waveform including a first plurality of pulses distributed among a second plurality of time slots, locating each of the pulses in the digitized waveform, computing a confidence value for each of the pulses, selecting a subset of the plurality of pulses, the subset including pulses having low confidence values computed, generating a set of unique waveforms corresponding to various combinations of the subset of pulses selected, computing a cross-correlation between each of the waveforms generated and the digitized waveform acquired, and selecting the waveform having the highest cross-correlation computed.
    Type: Application
    Filed: May 16, 2014
    Publication date: September 11, 2014
    Applicant: Schlumberger Technology Corporation
    Inventors: Caimu Tang, Mark S. Beattie
  • Patent number: 8788206
    Abstract: Borehole image data is compressed and transmitted to the surface one or more pixilated traces at a time. The compression methodology typically includes transform, quantization, and entropy encoding steps. The invention advantageously provides an efficient fixed point Karhünen-Loève like transform for compressing sensor data. A significant reduction in latency is achieved as compared to the prior art.
    Type: Grant
    Filed: April 23, 2008
    Date of Patent: July 22, 2014
    Assignee: Schlumberger Technology Corporation
    Inventor: Caimu Tang
  • Patent number: 8730764
    Abstract: A method for encoding a non-negative integer, for example, representative of MWD/LWD data, includes encoding at least a portion of the integer using at least a first order Fibonacci derived sequence. The remainder of the integer may be encoded using conventional Fibonacci encoding. The invention tends to improve coding efficiency, downhole and surface synchronization, and surface detection.
    Type: Grant
    Filed: July 30, 2009
    Date of Patent: May 20, 2014
    Assignee: Schlumberger Technology Corporation
    Inventors: Caimu Tang, Mark S Beattie
  • Publication number: 20120163523
    Abstract: A method for synchronizing a waveform received in a subterranean borehole with a transmitted waveform includes at least one of a phase synchronization, a symbol synchronization, or a frame synchronization method. The phase and symbol synchronization methods make use of distinct loop filters which process corresponding feedback signals so as to output phase clock and symbol clock adjustments. Frame synchronization methods accumulate a preamble correlation on a symbol stream having at least one repeating preamble.
    Type: Application
    Filed: December 22, 2010
    Publication date: June 28, 2012
    Applicant: SMITH INTERNATIONAL, INC.
    Inventor: Caimu Tang
  • Publication number: 20120046868
    Abstract: A closed-loop method for geosteering includes acquiring logging while drilling data and processing the logging while drilling data downhole while drilling to obtain a geosteering correction (a correction to the drilling direction based upon the LWD measurements). The geosteering correction is further processed downhole to obtain new steering tool settings which are then applied to the steering tool to change the direction of drilling. These steps are typically repeated numerous times without the need for uphole processing or surface intervention.
    Type: Application
    Filed: August 19, 2010
    Publication date: February 23, 2012
    Applicant: SMITH INTERNATIONAL, INC.
    Inventors: Borislav J. Tchakarov, Tsili Wang, Rodney S. Guenther, Thanh H. Cao, Caimu Tang
  • Patent number: 8024121
    Abstract: Borehole image data is compressed and transmitted to the surface one pixilated trace at a time. The compression methodology typically includes transform, quantization, and entropy encoding steps. The invention advantageously provides for sufficient data compression to enable conventional telemetry techniques (e.g., mud pulse telemetry) to be utilized for transmitting borehole images to the surface. By compressing and transmitting sensor data trace by trace the invention also tends to significantly reduce latency.
    Type: Grant
    Filed: January 25, 2008
    Date of Patent: September 20, 2011
    Assignee: Smith International, Inc.
    Inventor: Caimu Tang
  • Publication number: 20110026362
    Abstract: A method for encoding a non-negative integer, for example, representative of MWD/LWD data, includes encoding at least a portion of the integer using at least a first order Fibonacci derived sequence. The remainder of the integer may be encoded using conventional Fibonacci encoding. The invention tends to improve coding efficiency, downhole and surface synchronization, and surface detection.
    Type: Application
    Filed: July 30, 2009
    Publication date: February 3, 2011
    Applicant: SMITH INTERNATIONAL, INC.
    Inventors: Caimu Tang, Mark S. Beattie
  • Publication number: 20090192711
    Abstract: Borehole image data is compressed and transmitted to the surface one pixilated trace at a time. The compression methodology typically includes transform, quantization, and entropy encoding steps. The invention advantageously provides for sufficient data compression to enable conventional telemetry techniques (e.g., mud pulse telemetry) to be utilized for transmitting borehole images to the surface. By compressing and transmitting sensor data trace by trace the invention also tends to significantly reduce latency.
    Type: Application
    Filed: January 25, 2008
    Publication date: July 30, 2009
    Applicant: PathFinder Energy Services, Inc.
    Inventor: Caimu Tang
  • Publication number: 20090190850
    Abstract: Borehole image data is compressed and transmitted to the surface one or more pixilated traces at a time. The compression methodology typically includes transform, quantization, and entropy encoding steps. The invention advantageously provides an efficient fixed point Karhünen-Loève like transform for compressing sensor data. A significant reduction in latency is achieved as compared to the prior art.
    Type: Application
    Filed: April 23, 2008
    Publication date: July 30, 2009
    Applicant: PathFinder Energy Services, Inc.
    Inventor: Caimu Tang