Halliburton Energy Services, Inc.

Nanyang Technological University

National University of Singapore

Nam Nguyen

Yi Yang Ang

Yinghui Lu

Avinash Vinayak Taware

Gary Wayne Kainer

David Orlando Torres

Paris Smaragdis

Rebecca Corina Jachmann

Srinivasan Jagannathan

Joni Lie

David Alan Welsh

Chun Yang

Srinivasan Jagannanthan

Robert Zahler

Daniel Viassolo

Siew Hwa Chan

Joni Polili Lie

Darren Philip Walters

Freeman Hill

Kim Tiow Ooi

Teck Neng Wong

Yan Gao

Cheng Kun Wang

Clifford Lloyd Macklin

Nugroho Perhatianto

Colin Koo

David Lawrence Silver

Sumantri Lassemono

Franck Alexis Chollet

Chee Kiong John Chai

The disclosed embodiments include a method of downhole leak detection. The method of downhole leak detection includes obtaining physical signals detected by at least one physical sensor traveling along a wellbore. Additionally, the method includes detecting correlated sequences from the physical signals and constructing a covariance matrix based on the correlated sequences. The method also includes computing a spatial spectrum indicative of a location of a leak based on the covariance matrix.

Systems and methods to utilize sensors to provide spatial resolution in downhole leak detection

A method includes deploying a logging tool in a borehole formed in a subsurface formation, the logging tool having a transmitter and a receiver, wherein a condition that is present during logging comprises at least one of a shape of the borehole is non-circular and the logging tool is off-center within the borehole. The method includes emitting, by the transmitter, a signal into subsurface formation and detecting, by the receiver, a response to the signal being propagated through the subsurface formation. The method includes creating, from the response, a borehole image that includes features in the subsurface formation and correcting the features, wherein correcting the features comprises mapping points of a non-circular shape in the borehole image into a plane substantially perpendicular to an axis of the borehole.

Dip correction for non-circular borehole and off-center logging

Disclosed are systems and methods for processing broadband acoustic signals acquired by a plurality of acoustic sensors, using an array-signal-processing technique to compute fused-signal maps in the frequency domain for a plurality of frequency bins. In accordance with various embodiments, the fused-signal maps are combined across the frequency bins, with respective weightings that are based on eigenvalues of covariance matrices computed for the plurality of frequency bins. The combined maps can be used to locate an acoustic source in a wellbore.

Frequency weighting in broadband acoustic beamforming

A method for imaging a downhole formation. The method includes combining the captured images to generate a partial image of the formation, wherein the partial image includes captured images separated by gaps representing portions of the formation not captured with sensors what were disposed downhole. The method includes locating dips in the formation within the partial image and interpolating the partial image using the located dips within the partial image.

Dip detection in logging image processing

Disclosed are acoustic logging systems and methods that involve correlating broadband acoustic signals acquired by a plurality of acoustic sensors at multiple depths within a wellbore to compute covariance matrices and their eigenvalues in the frequency domain for a plurality of frequency bins. In accordance with various embodiments, acoustic sources are detected and located based on the eigenvalues viewed as a function of depth and frequency.

Leak localization using acoustic-signal correlations

A method for identifying a shape of a borehole may comprise disposing a downhole tool into the borehole, wherein the downhole tool comprises at least one transducer, transmitting a pressure pulse from the at least one transducer, wherein the pressure pulse is reflected as an echo, recording the echo with the at least one transducer, producing data points based at least in part on the echo, each data point including a radial distance value and an azimuthal value corresponding to the radial distance value, performing a pre-selection, fitting a geometric shape to a plurality of data points within the borehole, and sorting out at least one of the plurality of data points based at least in part on the shape. A system for identifying shape of a borehole may comprise at least one transducer and an information handling system.

Iterative borehole shape estimation of cast tool

A method includes deploying a logging tool in a borehole formed in a subsurface formation. The logging tool has a transmitter and a receiver. The method includes emitting, by the transmitter, a signal into subsurface formation. The method includes detecting, by the receiver, a response to the signal being propagated through the subsurface formation. The method includes creating, from the response, a borehole image that includes distorted features representing bedding dips in the subsurface formation. The method includes correcting the distorted features, wherein correcting the distorted features comprises mapping points of a non-circular shape in the borehole image to points on a circular shape.

The disclosed embodiments include leak detection systems and methods of downhole leak detection. In one embodiment, the method includes obtaining physical signals detected by a physical sensor over a period of time while the physical sensor is traveling along a wellbore, wherein the physical signals are acoustic signals of a leak. The method also includes performing a sequence extraction operation on the physical signals of the physical sensor to obtain a plurality of virtual signals associated with an array of virtual sensors, wherein each virtual sensor of the array of virtual sensors is located at a respective virtual distance relative to the physical sensor. The method further includes determining a signal strength of the plurality of virtual signals. The method further includes determining a location of the leak based on the signal strength of the plurality of virtual signals.

Systems and methods to utilize a sensor to provide spatial resolution in downhole leak detection

Disclosed are tools, systems, and methods for detecting one or more underground acoustic sources and localizing them in depth and radial distance from a wellbore, for example, for the purpose of finding underground fluid flows, such as may result from leaks in the well barriers. In various embodiments, acoustic-source detection and localization are accomplished with an array of at least three acoustic sensors disposed in the wellbore, in conjunction with array signal processing.

Acoustic array signal processing for flow detection

A passive array of acoustic sensors capture acoustic signals produced by sand movement. The array tool is deployed downhole where it passively listens for acoustic energy generated by sand movement in the well. Once acoustic signals are acquired, model-based frameworks are used to extract single and multiple sensor features from the acoustic signals. The extracted features are used as signatures to detect or classify the production of sand.

Wellbore sand detection using passive acoustic array

A method includes obtaining physical signals detected by a physical sensor traveling along a wellbore. The method also includes performing a first and second frame decomposition operations on a first and second set of physical signals detected by the physical sensor at first and second locations to obtain first and second pluralities of virtual signals associated with first and second arrays of virtual sensors. Each virtual sensor of the first and second arrays of virtual sensors is located at a virtual distance relative to the first and second locations, and the virtual distance corresponds to a physical distance. Additionally, the method includes computing first and second direction of arrival estimates of the first and second locations of the single physical sensor relative to a location of a downhole leak. Further, the method includes triangulating the first and second direction of arrival estimates to estimate the location of the downhole leak.

Systems and methods to use triangulation through one sensor beamforming in downhole leak detection

Various apparatus or methods are arranged to operate a tool in a wellbore, where the tool has a number of acoustic sensors. Scanning images obtained by the tool sensors along the borehole can be combined to increase the contrast of leak location with respect to background noise. A sequence of beamformed images, generated from signals captured by the tool as it moves over a range of depths of the wellbore, can be acquired. Each beamformed image may overlap at least one other beamformed image of the sequence. The beamformed images can be processed and the processed beamformed images can be combined, forming a stitched image. Additional apparatus, systems, and methods operable in providing stitched images can operate in a variety of applications.

Stitching methods to enhance beamforming results

A leak-detecting assembly can include an array of hydrophones. The array can be moved within a hydrocarbon well. A variation in the Doppler shift caused by a stationary acoustic source (such as a leak) while the array moves towards and away from that source can be determined based on information from the array of hydrophones. The assembly can be associated with a passive system that captures acoustic signals directly from the source or leak and estimates a location of the source or leak based on measurement of Doppler shift in each receiver.

Leak detection via doppler shift differences in moving hydrophones

Tools, systems, and methods may be configured for or include detecting one or more underground acoustic sources and localizing them in depth and radial distance from a wellbore using an array of at least three acoustic sensors disposed in the wellbore in conjunction with array-signal-processing that accounts for movement of the acoustic sensors and spatial aliasing by using adaptive time dependent modelled steering vector weights.

Continuous beamforming while moving: method to reduce spatial aliasing in leak detection

The disclosed embodiments include leak detection systems and methods of downhole leak detection. In one embodiment, the method includes obtaining physical signals measured by at least one physical sensor traveling along a wellbore. The method also includes performing a frame decomposition operation on the physical signals of a first of the at least one the physical sensor to obtain a plurality of virtual signals associated with an array of virtual sensors, each virtual sensor of the array of virtual sensors being located at a virtual distance relative to the first physical sensor, the virtual distance corresponding to a physical distance. The method further includes synchronizing the virtual signals of the array of virtual sensors. The method further includes computing a spatial spectrum indicative of a location of a leak based on the synchronized virtual signals.

Growing community of inventors

Singapore, Singapore

Nam Nguyen