A borehole inspection device and method of using the same to measure the condition of the bottom extent of a borehole, the system having a head unit assembly with top and bottom sides and including at least one downwardly extending force sensor configured to measure a reaction force applied to the at least one sensor as it engages a bottom extent of the borehole, the inspection device being configured to be lowered into a borehole and to bring the sensor(s) into contact with the bottom extent wherein continued downward movement of the head unit creates the reaction force on the sensor(s) to determine at least one of a location of an associated debris layer, a bearing capacity of the associated debris layer, the thickness of the associated debris layer, the location of an associated bearing layer and/or the bearing capacity of the associated bearing layer.

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.

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.

Apparatus and methods to investigate a multiple nested conductive pipe structure can be implemented in a variety of applications. An electromagnetic pulsed tool disposed in the multiple nested conductive pipe structure in a wellbore can make a set of log measurements and provide a measured log at different depths in the multiple nested conductive pipe structure. A test setup or library can provide a set of small defect log measurements. Processing circuitry can process the set of log measurements to generate thickness estimations of the multiple nested conductive pipes and processing circuitry can process the set of small defect log measurements to generate small defect thickness estimations. Processing circuitry can solve a system of equations involving the thickness estimations and the small defect thickness estimations to generate thickness variations for the multiple nested conducted pipes over the different depths. Additional apparatus, systems, and methods are disclosed.

Apparatus and methods to investigate a multiple nested conductive pipe structure can be implemented in a variety of applications. An electromagnetic pulsed tool disposed in the multiple nested conductive pipe structure in a wellbore can make a set of log measurements and provide a measured log at different depths in the multiple nested conductive pipe structure. A test setup or library can provide a set of small defect log measurements. Processing circuitry can process the set of log measurements to generate thickness estimations of the multiple nested conductive pipes and processing circuitry can process the set of small defect log measurements to generate small defect thickness estimations. Processing circuitry can solve a system of equations involving the thickness estimations and the small defect thickness estimations to generate thickness variations for the multiple nested conducted pipes over the different depths. Additional apparatus, systems, and methods are disclosed.

Waves from cement bond logging with a sonic logging-while-drilling tool (LWD-CBL) are often contaminated with tool waves and may yield biased CBL amplitudes. The disclosed LWD-CBL wave processing corrects the first echo amplitudes of LWD-CBL before calculating the BI. The LWD-CBL wave processing calculates a tool wave amplitude and a phase angle difference as the difference of the phases between the tool waves and casing waves. The tool waves are then used to correct the LWD-CBL casing wave amplitude and remove errors introduced from tool waves. In conjunction with the sets of operations described, the LWD-CBL wave processing also include array preprocessing operations. Array preprocessing may employ variation of bandpass filtering and frequency-wavenumber (F-K) filtering operations to suppress tool wave.

A method can include, using a downhole tool, acquiring ultrasonic echo data of a borehole, where the ultrasonic echo data include echoes representative of material and borehole geometry responsive to reflection of ultrasonic energy that has a wide-band frequency range; filtering the ultrasonic echo data using at least one selected filter for multi-band frequency filtering corresponding to different frequency ranges of the wide-band frequency range to generate filtered data; and processing the filtered data to generate attribute values representative of physical characteristics the material, the borehole geometry, or the material and the borehole geometry.

A method for classifying a subterranean formation includes rotating an ultrasonic logging tool in a borehole penetrating a formation. The ultrasonic logging tool includes an ultrasonic transducer and an array of spaced apart ultrasonic receivers deployed on a logging tool body. The ultrasonic logging tool measures an azimuthal shear slowness image and an azimuthal compressional slowness image while rotating in the borehole. The images are evaluated to classify the homogeneity/heterogeneity and isotropy/anisotropy of the formation.

The invention relates to geophysics and can be utilised for monitoring integrity of casings, tubings and other tubular strings in oil and gas wells. The essence of this invention is an apparatus for defectoscopy of downhole casings, which comprises an electromagnetic field generation unit, pick-up sensor unit, and data acquisition and processing unit, with all these units mounted in a housing. The technical result consists in enhancing the informative value of measurements in surveyed pipes both longitudinally and azimuthally, thus improving the defectoscopy accuracy.

A method is provided for non-intrusively determining cross-sectional variation of a fluidic channel. The method includes creating a pressure pulse in a fluidic channel using a hammer to strike an external surface of a fluidic channel. The method also includes sensing, by one or more sensors, reflections of the pressure pulse; and obtaining, from the one or more sensors, a measured pressure profile based on the sensed reflections of the pressure pulse. A forward model of cross-sectional variation of the fluidic channel is generated based on a baseline simulation. Using the forward model, a simulated pressure profile is generated. Using the measured pressure profile and the simulated pressure profile, an error is determined. When the error is outside a predetermined threshold, the forward model is updated based on the error. An estimate of cross-sectional variation of the fluidic channel based on the forward model is displayed.