Reeves Wireline Technologies Limited

Weatherford Technology Holdings, LLC

James Anthony Whetton

Peter Adrian Spencer Elkington

Peter Adrian Elkington

Said Assous

Hamed Chok

Alexander Gorban

Peter Elkington

Evgeny Mirkes

Joanne Tudge

Jeremy Levesley

Component weight and/or volume fractions of subterranean rock are determined. A formation model generates mineral and fluid concentration data from which elemental concentrations are calculated. Forward modeling produces a simulated energy spectrum, and simulation produces a simulated constraining log. Spectra is generated by detecting gamma radiation with a neutron logging tool, and a constraining log is generated. The spectrum and the simulated energy spectrum are compared with resultant error determined. The constraining log and simulated constraining log are compared with resultant error determined. The formation model generates further mineral and fluid concentration to calculate further elemental concentrations. Forward modeling produces further simulated energy spectrum signal and further constraining logs. The spectrum signals and further simulated spectrum signal are compared with resultant error determined. The constraining log and further simulated constraining log are compared, and resultant error is determined. The mineral and fluid concentration are selected that result in minimal error.

Method of and apparatus for determining component weight and/or volume fractions of subterranean rock

In acoustic well logging, for each inversion depths of a well at which logging of data occurs, acoustic log signals representative of waveforms received at acoustic receivers are processed in a frequency domain to derive field dispersion curve(s). A neural net is operated to generate formation shear slowness value(s) from the curve(s), and resulting signal(s) indicative of shear slowness values are saved, transmitted, plotted, printed or processed. An apparatus for carrying out the method includes a logging tool having at least one activatable acoustic wave source; spaced and acoustically isolated therefrom in the logging tool an array of acoustic detectors that on the detection of acoustic wave energy generate electrical or electronic log signal(s) characteristic of acoustic energy waves detected by the acoustic detector(s); and at least one processing device associated with or forming part of the logging tool for processing the log signal(s).

Method of and apparatus for carrying out acoustic well logging

To process geological log data, a two-dimensional set of log values recorded at a plurality of points is obtained about a borehole periphery, and over a chosen length along the borehole. The set of log values are decomposed by identifying in the set one or more main functions indicative of one or more main geological layer features of the rock penetrated by the borehole and removing log values corresponding to values of the main functions from the set of log values. Further decomposing the set of log values can be performed, as necessary iteratively, based on one or more subsidiary functions. The log values of the set remaining after identification and removal of values are designated as texture. Functions indicative of the main and subsidiary layer features and the texture are used to construct a synthesized volume representing the rock removed during creation of the chosen length of the borehole.

Method and apparatus for processing log data

Systems and methods for optimizing bed boundary locations and prediction of associated petrophysical property values of a wellbore in a reservoir formation are disclosed. To optimize bed boundary locations and predict petrophysical property values, a process can be used in which a high resolution wellbore log is used to get an initial estimate of boundary positions. The initial estimate can then be used to constrain a joint optimization of bed positions and associated petrophysical property values. Such a process automates both the generation of a single set of boundaries that are common to all measurements and the prediction of petrophysical properties via joint inversion. The same inversion process can be used to derive quality indicators on the corrected bed boundary locations and the petrophysical property values.

System and method for joint inversion of bed boundaries and petrophysical properties from borehole logs

A method of processing borehole log data to create one or more image logs involve modelling the log data as components of an image in the form i(x, y)=l(x, y)&#xd7;r(x, y) (1), in which i(x, y) is an image representative of the log data, l(x, y) denotes an illumination value of the image at two-dimensional spatial co-ordinates x, y, and r(x, y) denotes a surface reflectance value at the co-ordinates x, y. Equation (1) is transformed to a logarithmic domain, and a Fourier transform is obtained of the resulting logarithmic domain expression to obtain a Fourier domain expression. The Fourier domain expression is high-pass filtered, and an inverse Fourier transform is obtained of the resulting filtered Fourier domain expression. An exponential operation is performed on the result of inverse Fourier transform to obtain a filtered image model expression. Values of the filtered image model expression are mapped to respective color values across the range of the filtered image model expression values. The mapped color values can then be displayed, printed, saved and/or transmitted as one or more image logs.

Borehole log data processing methods

A method of processing borehole log data to create one or more image logs involve modeling the log data as components of an image in the form i(x, y)=l(x, y)&#xd7;r(x, y) (1), in which i(x, y) is an image representative of the log data, l(x, y) denotes an illumination value of the image at two-dimensional spatial co-ordinates x, y, and r(x, y) denotes a surface reflectance value at the co-ordinates x, y. Equation (1) is transformed to a logarithmic domain, and a Fourier transform is obtained of the resulting logarithmic domain expression to obtain a Fourier domain expression. The Fourier domain expression is high-pass filtered, and an inverse Fourier transform is obtained of the resulting filtered Fourier domain expression. An exponential operation is performed on the result of inverse Fourier transform to obtain a filtered image model expression. Values of the filtered image model expression are mapped to respective color values across the range of the filtered image model expression values. The mapped color values can then be displayed, printed, saved and/or transmitted as one or more image logs.

Inverting nuclear log data for a geological formation surrounding a borehole involves acquiring nuclear log data for a borehole portion using a moveable nuclear logging tool and acquiring additional log data for the borehole portion using another logging device with superior resolution. Boundaries between adjacent zones are identified that exhibit an attribute of the geological formation to a detectably contrasting degree. From pre-acquired data describing one or more characteristics of the nuclear logging tool, a modeled log of the attributes is generated over the borehole portion, and a zone response is calculated from the pre-acquired data for each zone by using the boundaries to define an initial measure of the depth of each zone and ascribing a value of the attribute in dependence on the depth of each zone. The attribute of each zone is then calculated by deconvolving the nuclear log data using the zone response to minimize the difference between the nuclear log data and the convolution of the zone response and the attribute.

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Nottingham, United Kingdom

James Anthony Whetton