Abstract:
In some embodiments, apparatus and systems, as well as methods, may operate to enable moving a drill string through a borehole while acquiring data generated by a plurality of receiver sub-arrays included in a drill string. The sub-arrays may be separated by one or more sources of sonic energy, as well as by a non-aliased receiver spacing distance, a distance associated with a selected aperture of investigation, or a distance associated with a formation slowness. The sonic energy may be received by the sub-arrays at a plurality of stations. Data may be collected at a telemetry receiver.
Abstract:
Apparatus and methods for measuring gamma ray energy spectra wherein the gain of the measurement system is continuously and automatically adjusted to a standard gain. Gain of the system is controlled automatically through analysis of the measured energy spectra. Alternately, the gain of the system is controlled by the use of a calibration source and the operation of the system at a standard and amplified gain. Gain control can be improved further by combining both the spectral analysis and calibration source methodology. The system can be embodied in a wireline or logging-while-drilling borehole logging systems that measure naturally occurring or induced gamma ray spectra. The system can also be used in non-borehole applications including non-borehole gamma ray spectral systems such as computer-aided-tomography scan systems, security scanning systems, radiation monitoring systems, process control systems, analytical measurement systems using activation analysis methodology, and the like.
Abstract:
The invention relates to monitoring of fluid-filled domains in various media including, for example, subterranean formations, construction elements, bones. Claimed are a method for determining characteristic sizes of a fluid-filled crack in a medium and a system for implementation thereof. In accordance with this method, oscillations of the fluid-filled crack are registered. Wave characteristics of standing interface waves propagating along the fluid-filled crack surfaces are determined based on the registered oscillations taking medium and fluid properties into account. The fluid-filled crack characteristic sizes are calculated based on the determined wave characteristics of the standing interface waves. Also claimed are methods for detecting creation or existence of a fluid-filled crack in a medium, for hydraulic fracturing in a subterranean formation, for detecting cessation of propagation of a fluid-filled crack in a medium, as well as a method for determining properties of a fluid filling a layer in a medium, of the medium and of the layer. Analysis of oscillations of fluid-filled domains based on interface waves propagating along their surfaces underlies all the methods listed above. The proposed methods, by virtue of the simplicity of data processing inherent thereto, can be implemented in real time.
Abstract:
The present invention provides a method of determining a property of an earth formation using an acoustic logging tool on a bottomhole assembly (BHA) in a borehole in the earth formation. At least one transmitter is used in the acoustic logging tool for generating acoustic signals into the formation at a first depth of the BHA. A plurality of receivers is used on the logging tool for receiving signals indicative of a parameter of interest. The plurality of receivers are spaced apart axially from the at least one transmitter. The measurements are repeated at least one additional depth of the BHA. The signals at the first depth and subsequent additional depths are sorted into at least one of (i) a common receiver gather, (ii) a common offset gather, and, (iii) a common-midpoint gather, giving re-sorted signals. The re-sorted signals are processed to obtain the parameter of interest.
Abstract:
The present invention provides a method and apparatus for using an acoustic logging tool conveyed in a borehole in an earth formation for determining a characteristic of the formation. The method comprises using a first acoustic source for generating an acoustic signal in the earth formation at a first frequency. A second acoustic source spaced apart from the first source is used for generating an acoustic signal in the earth formation at a second frequency different from the first frequency. An acoustic receiver is used for receiving a third acoustic signal indicative of said characteristic. The third acoustic signal has a frequency substantially equal to a difference between the first frequency and the second frequency. The third acoustic signal is produced by a nonlinear interaction between the first signal and the second signal in a portion of said earth formation.
Abstract:
A method and device are shown for detecting the characteristics of a cement annulus between a casing in a borehole and the surrounding earth formations in a slickline cement bond logging operation. An acoustic logging tool is utilized which produces a pure signal downhole. The received acoustically transmitted energy produces electrical signals indicative of both the amplitude of the received energy and variable density log data. Both the amplitude data and the variable density log data are captured in memory downhole by the use of a time amplitude matrix which stores a limited number of data points for producing a cement bond log at the well surface.
Abstract:
An acoustic tool that provides a programmable source waveform is disclosed. Numerous advantages may be achieved from the configurability of the source waveform. Notably, acoustic logs at multiple frequencies may be acquired with a single pass. The waveform may be frequency-adapted to maximize formation response and amplitude adapted for gain control. In one embodiment, the acoustic tool comprises: a controller, a digital-to-analog controller (DAC), an acoustic transducer, and a linear driver. The DAC converts a digital waveform from the controller into an analog waveform. The acoustic transducer converts an electrical signal into an acoustic signal. The linear driver receives the analog waveform from the DAC and responsively provides the electrical signal to the acoustic transducer. The electrical signal is proportional to the analog waveform. The tool may further include a memory for storing the digital waveform and/or software for generating the digital waveform.
Abstract:
The method of and a device for using this method, on equipment or assigned to equipment for working a material, for investigating and identifying the nature of the material, which is to be worked and for making available at least one operating parameter for the optimized pre-setting of the working equipment, provides for the use of a sensor, preferably assigned directly to the working tool, such as a hammer drill, in order to detect shock waves generated or induced in the tool. From the shock wave signal measured, at least one distinguishing feature characteristic of the material to be worked, is extracted and evaluated for the comparative classification of the material by means of an algorithm. Preferably, an external force, especially the contacting force, acting on the working equipment, is taken into consideration for the algorithmic evaluation.
Abstract:
An acoustic tool that provides a programmable source waveform is disclosed. Numerous advantages may be achieved from the configurability of the source waveform. Notably, acoustic logs at multiple frequencies may be acquired with a single pass. The waveform may be frequency-adapted to maximize formation response and amplitude adapted for gain control. In one embodiment, the acoustic tool comprises: a controller, a digital-to-analog controller (DAC), an acoustic transducer, and a linear driver. The DAC converts a digital waveform from the controller into an analog waveform. The acoustic transducer converts an electrical signal into an acoustic signal. The linear driver receives the analog waveform from the DAC and responsively provides the electrical signal to the acoustic transducer. The electrical signal is proportional to the analog waveform. The tool may further include a memory for storing the digital waveform and/or software for generating the digital waveform.
Abstract:
A system and method for viewing well log data is disclosed. A wellbore identifier is entered into a remote display device. The display device is at a first location separate from a facility operated by a well logging operator. The well identifier is transmitted to a first database having ancillary data therein. The first database is operated by the well logging operator. The ancillary data are sent to the first location, and the ancillary data and data recorded from a well logging instrument disposed in a wellbore are presented on the display device.