Baker Hughes Corporation

Saudi Arabian Oil Company

Weatherford Technology Holdings, LLC

Western Atlas International, Inc.

Weatherford International, Inc.

Darryl E Trcka

David M Chace

Stephen Riley

Steve Riley

Pingjun Guo

W Allen Gilchrist, Jr

Songhua Chen

Thomas Kruspe

Shouxiang Mark Ma

Benoit J Guivarch

Ole G Engels

Paul James Wilson

Joseph Gregory Barolak

Richard R Pemper

Ole Engels

Mike Gillen

Michael E Gillen

Robert Wilson

Allen Gilchrist

Rene W Mayer

Ali R Belowi

David M Chase

Methods and systems for quantitatively determining pack density within a section of a wellbore are disclosed. The method compares acquired pulsed neutron measurements to models of the section having zero pack density and one hundred percent pack density and extrapolates the measured pulsed neutron data between those two extremes to quantitatively determine pack density. The methods and systems allow hydrocarbon saturation and pack density to be determined in a single trip of a pulsed neutron tool.

Pulsed neutron determination of gravel pack density

Provided are embodiments of systems, computer medium and computer-implemented methods for logging using a customizable logging tool. In some embodiments, the logging tool is capable of being disposed in a borehole formed in a geologic formation. The logging tool includes a source for emitting signals into the geologic formation surrounding the borehole and a plurality of detectors for detecting signals generated as a result of emission of signals by the source into the geologic formation surrounding the borehole. The plurality of detectors are independently repositionable such that a source-to-detector spacing for the detectors is independently variable, to provide optimum signal depending on the characteristics of the target reservoir, the borehole, and the tool source and detectors.

Systems, computer medium and computer-implemented methods for logging using a logging tool with adjustable detectors

Provided in some embodiments are systems and methods for monitoring cement quality of a cased well. Embodiments include conducting a cement-bond logging and a first pulsed neutron (PN) logging to generate a cement-bond log (CBL) and first pulsed neutron log (PNL) for the well, determining a first cement quality index (CQI) for the well based on the CBL and the first PNL, in response to determining that mud effects for the well have dissipated, conducting a second PN logging to generate a second PNL for the well, determining a second CQI for the well based on the CBL and the second PNL, determining a tuned CQI for the well based on the first CQI and the second CQI, conducting a follow-up PN logging to generate a follow-up PNL for the well, and determining a cement quality log for the well based on the tuned CQI and the follow-up PNL.

Systems and methods for monitoring casing cement integrity

A neutron logging tool has multiple detectors spaced about the circumference of the tool. The detectors are shielded from each other such that each detector detects gamma rays from the area of the borehole and formation to which it is closest. The log readings from each detector can be associated with the orientation of that detector. The orientation-specific log readings can then be aggregated to form an azimuthal log which can be used to analyze pre-fractured and/or post-fractured formations.

Neutron logging tool with multiple detectors

An apparatus for detecting gamma ray (GR) radiation having a plurality of detector cells arranged in an array is disclosed. Each cell includes a housing having an aperture, the housing comprising a GR absorbing material, and a GR detector disposed within the housing such that external gamma rays are received at the GR detector via the aperture. The apertures of each cell are aligned.

Apparatus and method for detecting gamma ray radiation

Data from a string of multiple formation evaluation data sensor are evaluated by an expert system. Based on the analysis, the logging speed is increased if all the sensors justify it, and is reduced if any of the sensors require a reduced logging speed. Alternatively, the sensitive volume of a NMR sensor is altered based on a determination of a fraction of the sensitive volume that includes a borehole fluid. It is emphasized that this abstract is provided to comply with the rules requiring an abstract which will allow a searcher or other reader to quickly ascertain the subject matter of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims.

Automatic adjustment of NMR pulse sequence to optimize SNR based on real time analysis

A method, apparatus, and machine-readable medium for evaluating an earth formation having a fluid mixture including oil and water therein. The earth formation is irradiated with a source and radiation resulting from interaction of the radiation with nuclei is measured at at least two detectors. A fluid zone parameter (FZP) indicative of oil saturation is determined and values of the FZP are established for at least two different values of oil saturation. A value of the oil saturation is estimated using the determined value of the FZP and established values of the FZP. The process may be repeated at a plurality of depths and the determined value of the FZP is displayed at the plurality of depths.

Measurement of water-oil saturation using pulsed neutron instrumentation

Measurements made with a pulsed neutron source and three or more gamma ray detectors are used to estimate the silicon and oxygen content of earth formations.

Method and apparatus for determining silicon content of the earth formations in cased well bores

A pulsed neutron tool with three or more detectors is used for making measurements inside casing. The measurements may be used to determine gas saturation at a constant gas pressure, pressure at constant gas saturation, or to determine both gas saturation and gas pressure.

Determination of gas pressure and saturation simultaneously

Measurement of formation gas saturation in cased wellbores using pulsed neutron instrumentation

Measurement of formation gas pressure in cased wellbores using pulsed neutron instrumentation

Data from a string of multiple formation evaluation data sensor are evaluated by an expert system. Based on the analysis, the logging speed is increased if all the sensors justify it, and is reduced if any of the sensors require a reduced logging speed. Alternatively, the sensitive volume of a NMR sensor is altered based on a determination of a fraction of the sensitive volume that includes a borehole fluid.

A well logging instrument including a plurality of detectors having different precisions and accuracies, the more precise detectors generally having lower accuracies. The detectors are responsive to the interaction of radiation from a suitable source on the instrument with earth formations. Outputs from the plurality of detectors are smoothed and combined to provide processed measurements with improved accuracy and precision.

Apparatus and method for determining thermal neutron capture cross section of a subsurface formation from a borehole using multiple detectors

A pulsed neutron source irradiates an earth formation. The irradiation produces Nfrom Oin a fluid in the borehole, and the gamma rays produced by the subsequent decay of Nare detected by a plurality of spaced apart detectors. The count rates of the detectors are accumulated over a time sampling interval to produce temporal signals. Processing of the temporal signals using correlation, differentiation and/or semblance techniques is used for determination of the flow velocity of one or more fluids in the borehole.

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Houston, TX, United States of America

Darryl E Trcka