Abstract: A device 1 for measuring a fluid flow FF velocity and direction comprises: —a pivotable means 2 adapted to rotate at a pivotable means rotation velocity and direction depending on the fluid flow velocity and direction when in contact with the fluid flow, —a modulator 3 coupled to the pivotable means and adapted to rotate in conjunction with the pivotable means, —a fiber optical arrangement for providing an incident beam IB to the modulator and for receiving a return beam RB from the modulator, —the incident beam IB comprising an incident signal, the return beam RB comprising a modulated signal, the modulator 3 modulating the incident signal so as to form the modulated signal depending on the pivotable means 2 rotation velocity and direction.

Abstract: A technique facilitates the collection of improved gravitational acceleration measurements and enables use of those measurements in analyzing environmental characteristics of a subterranean region. In one embodiment, a downhole tool is constructed with a gravimeter having a quantum source and an associated detector. The quantum source and detector use a velocity of the quantum source for determining gravitational acceleration measurements that can be employed in evaluating subterranean characteristics.

Abstract: Apparatus, methods for forming the apparatus, and methods for operating the apparatus provide a value for a formation property or a borehole property from measurements obtained in a well. The value may be generated from determining a weighted average of the value for the formation property or the borehole property using both values corresponding to different azimuths and weights corresponding to different azimuths.

Abstract: A steering tool configured for making azimuthal and non-azimuthal formation evaluation measurements is disclosed. In one embodiment a rotary steerable tool includes at least one formation evaluation sensor deployed in the steering tool housing. The steering tool may include, for example, first and second circumferentially opposed formation evaluation sensors or first, second, and third formation evaluation sensors, each of which is radially offset and circumferentially aligned with a corresponding one of the steering tool blades. The invention further includes methods for geosteering in which a rotation rate of the steering tool housing in the borehole (and therefore the rotation rate of the formation evaluation sensors) is controlled. Steering decisions may be made utilizing the formation evaluation measurements and/or derived borehole images.

Abstract: A method of compensating a density log comprises the step of compensating the far density by adding a correction at a given point in the density log wherein: (a) the correction comprises at least a first correction function and optionally a second correction function; (b) when the correction includes both the first and second correction functions they respectively are corrections for “slow-moving” and “fast-moving” perturbations at the said given point; and (c) regardless of whether the correction includes the second correction function the first correction is filtered by a long filter.

Abstract: A method for obtaining a parameter of interest related to an earth formation, the method including: obtaining nuclear magnetic resonance (NMR) data from an NMR tool investigating the earth formation with a plurality of pulse sequences of radio frequency energy, each pulse sequence having a unique frequency, a first train of pulses having a first interecho time (TE1) and a second train of pulses having a second interecho time (TE2) different from the first interecho time; relating the NMR data to a partial porosity at points to establish an NMR response model; solving the NMR response model to calculate the partial porosity at each of the points in the earth formation; summing the partial porosity for each of the points corresponding to each depth of investigation to provide a pore volume; and associating each pore volume with the corresponding depth of investigation to provide the parameter of interest.

Abstract: In some embodiments, apparatus and systems, as well as methods, may operate to acquire borehole standoff data (321), segregate the standoff data into a plurality of azimuthal bins (363), derive a plurality of diameters from the standoff data in the bins, determine an average borehole diameter from the plurality of diameters (367), calculate a standard deviation from the average borehole diameter (375), and compute a caliper measurement (383), a major elliptical axis length, and a minor elliptical axis length based on the average borehole diameter and the standard deviation (387).

Abstract: An apparatus and method for measuring the conductivity of borehole fluid. Based on the fluid conductivity, the fluid type may also be identified. The apparatus and method can be useful in differentiating between native water and injected water in oil recovery operations. The apparatus and method presented can also be used to calibrate testing and production equipment allowing for more reliable and accurate measurements. The apparatus and method presented can further be used to better characterize water to oil ratio in reservoirs.

Abstract: Methods and related systems are described for measuring fluid pressure in a microchannel. A number of flexible membranes are positioned at locations along the microchannel such that pressure of the fluid in the microchannel causes a deformation of the membranes. An optical sensing system adapted and positioned to detect deformation of the membranes that thereby determine the pressure of the fluid flowing in the microchannel at a number of locations along the microchannel.

Abstract: A gravel pack evaluation tool comprised of a low energy radiation source and multiple directionally-collimated radiation detectors to analyze small, azimuthal segments of a gravel pack. Methods of use are also provided. Collimators and radiation shielding used in conjunction with multiple detector arrays allow an azimuthal segmented view of a gravel pack, particularly at certain defined depths into a gravel pack. Radioactive tracers may be used in conjunction with these tools to produce enhanced images of gravel packs and formations.

Abstract: Methods and related systems are described for predicting a response of a gamma ray measurement tool located in a borehole surrounded by a subterranean formation. A response of the tool is calculated according to one or more properties at a plurality of spatial locations in relation to the measurement tool using a forward model that assumes a non-linear relationship between the one or more properties at the plurality of spatial locations and the corresponding response of the tool.

Abstract: A method for obtaining a fluid migration profile for a wellbore, comprising the steps of obtaining a static profile for a logged region of the wellbore, obtaining a dynamic profile for the logged region of the wellbore, digitally filtering the dynamic profile to remove frequency elements represented in the static profile, to provide a fluid migration profile, and storing the fluid migration profile on a computer-readable memory.

Abstract: A method for estimating resistivity of a formation includes: selecting spectra collected by pulsed neutron instrument disposed down a wellbore traversing the formation, the spectra including capture interactions and inelastic interactions; deconvolving the spectra to estimate an elemental yield; converting the elemental yield to a total concentration value; subtracting a concentration value for drilling mud and a concentration value for the formation from the total concentration value to estimate a concentration in fluid within the formation; and converting the fluid concentration value to a resistivity value. A computer program product and an instrument are provided.

Abstract: Methods and apparatus for detecting a coating on a downhole fluid sensor are disclosed. A coating may refer to a solid or liquid film on a sensor interface with the sampled fluid, caused by contaminants. Detecting a coating may be accomplished by determining a sampled fluid type and measuring at least one fluid parameter using one or more downhole fluid sensors. The coating detection further includes determining whether the measured parameters are within ranges corresponding to the determined fluid type. Additionally or alternatively, measured parameter values that remain substantially stable during sampled fluid pumping may also indicate a coated sensor.

Abstract: A method for determining the water saturation of an underground formation traversed by a borehole, the method composing: determining a first parameter (?) that is representative of the critical exponent of the electrical conductivity of the formation: determining a second parameter (Wc or Sc or ?c) that is representative of the formation percolation threshold; measuring a first set of formation properties; and combining, said first set of formation properties, first and second parameters in order to determine the water saturation (Sw) of said underground formation.

Abstract: NMR spin echo signals are acquired downhole. Principal Component Analysis is used to represent the signals by a weighted combination of the principal components and these weights are telemetered to the surface. At the surface, the NMR spin echo signals are recovered and inverted to give formation properties.

Abstract: A method of determining the porosity and fluid saturation for a given volume of an underground formation through which a borehole is drilled, the method comprising: measuring, from within the borehole, parameters relating to characteristics of the underground formation; determining volumetric values for resistivity, hydrogen index, density and neutron capture cross-section for the given volume from the measured parameters, each volumetric value including a contribution from formation matrix, water, oil and gas; determining, from the volumetric values, the volumes of rock matrix, pore water, oil and gas, and the salinity of the pore water; and determining the porosity and fluid saturation of the volume of the formation from the determined volumes and salinity.

Abstract: A method of analyzing characteristics of a subterranean formation includes transmitting a signal at least partially into a material of the subterranean formation such that the signal is transformed in a manner indicative of a characteristic of the material, receiving the transformed signal from the material, converting the transformed signal into image data indicative of the characteristic of the material, applying a first set of machine executable rules to the image data to produce segmented image data, wherein portions of the image that are sufficiently related according to the applied rules are grouped into segments, and analyzing, according to a second set of machine executable rules, the segmented image data to produce a geological profile of the subterranean formation.

Abstract: Measurements made by a wireline-conveyed pulsed neutron tool with two or more gamma ray detectors are used to provide a mineralogical and/or elemental image of the formation. This may be used in reservoir navigation and in furthering the understanding of the geology of the prospect.

Abstract: Well log data is assigned depositional labels by a soft computing method. A model is trained on an expert-interpreted well log by segmenting, assigning fuzzy symbols to the segments, and calculating attribute values for units labeled by the expert. From these values, classifiers are trained for each of a number of depositional types. Finally, a model is developed for translating fuzzy symbols into depositional labels. Once trained, the model is applied to well log data.

Abstract: A method of analyzing characteristics of a subterranean formation includes applying a wavelet transform to measured data or to derived data obtained from the measured data, the measured data obtained by measuring a physical property at each of a plurality of positions in a borehole that penetrates the subterranean formation; selecting one or more scales for analyzing wavelet coefficients; performing a segmentation of the data; calculating a distribution of wavelet coefficients for each scale, for one or more spatial directions of wavelet transform application, for the wavelet transform of the data and for each segment that belongs to the portion on which the wavelet transform has been calculated; and for each segment, analyzing a distribution of the data and the distribution of the wavelet coefficients for each scale in terms of their overlap with corresponding distributions of training samples to produce a geological interpretation of the subterranean formation.

Abstract: In general, in one aspect, the invention relates to a method for evaluating a volcanic reservoir formation having volcanic rock forming elements and a borehole penetrating the volcanic reservoir formation. The method includes controlling chlorine concentration in an environment of the borehole and a tool operation to enable neutron capture spectroscopy measurements of the volcanic rock forming elements, obtaining neutron capture spectroscopy data relating to the volcanic rock forming elements from borehole logging tools, determining a lithology of the volcanic reservoir formation based on at least the neutron capture spectroscopy data, and generating an evaluation of the volcanic reservoir formation based on at least the lithology.

Abstract: A logging-while-drilling density sensor includes a gamma ray source and at least two NaI detectors spaced apart from the source for determining measurements indicative of the formation density. An analytic function based on a heuristic model is used to predict the measured response as a function of offset, mud density and formation density. The model may be used to provide a caliper measurement where acoustic caliper data are unreliable.

Abstract: Methods are provided for determining the locations and heights of fractures in a subterranean formation using a neutron-emitting logging tool. Utilizing predetermined relationships (1) between logging tool count rates and associated apparent formation hydrogen index values and (2) between logging tool count rate ratios and associated apparent formation hydrogen index values, the methods detect the presence and heights in the formation of proppant containing high thermal neutron capture cross section material in a manner substantially eliminating proppant determination uncertainty resulting from a prior change in formation hydrogen index values. A second, associated, method employing logging tool count rates and count rate ratios to determine the presence of proppant containing high thermal neutron capture cross section absorbers utilizes a crossplot of count rate versus ratio.

Abstract: 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.

Abstract: An apparatus and a method for determining characteristics of earth formations traversed by a borehole that compensates the mudcake and standoff effects with fewer than usual detectors. The apparatus includes an radiation source effective to generate first and, spatially as well as temporally separate, second X-rays for irradiating earth formations from first and second entrance angles, one or more X-ray detectors capable of generating a first and a second signal indicative of the intensity of the first and second X-rays returned from earth formations to the detectors and a housing accommodating the radiation source and the detectors.

Abstract: Method and system for analyzing electrical pulses contained in a pulse train signal representative of the interaction of x-ray bursts with a nuclear detector configured for subsurface disposal. The pulse train signal is sampled to form a digitized signal. The total energy deposited at the detector during an x-ray burst is determined from the digitized signal, and a count rate of x-ray pulses from the burst is determined. A subsurface parameter is determined using the total energy deposit.

Abstract: A method for estimating a property downhole is provided, which, in one aspect, may include receiving a core at a receiving end of a downhole tool while removing a portion of the received core distal from the receiving end of the tool, obtaining measurements by a sensor downhole, and processing the measurements to estimate the property of interest.

Abstract: A combination of a shallow-reading and a deep-reading, azimuthally sensitive, multiple propagation devices is used for providing depth images the earth formation with different depth of investigation. 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. 37 CFR 1.72(b).

Abstract: A method of analysing results from an electromagnetic survey of an area that is thought or known to contain a subterranean resistive or conductive body within a background strata configuration is described. The method comprises providing a set of electromagnetic field data obtained using at least one electromagnetic receiver and at least one electromagnetic source for a range of source-receiver separations, e.g. providing conventional controlled-source electromagnetic survey data. A subset of the electromagnetic field data is identified that comprises data obtained for source-receiver separations greater than a selected threshold offset. The threshold offset is chosen so that data beyond this offset are characteristic of magnetotelluric data. Thus the subset of data is then processed in accordance with a first technique to obtain information on the background strata configuration.

Abstract: A method and a computer program product for estimating the true intrinsic relaxation time T2 and the internal gradient Gint for a multi-frequency nuclear magnetic resonance imaging tool for well logging includes providing at least two frequencies in a plurality of echo trains, evaluating the signal decay in each echo train, quantifying the signal decay and correlating the signal decay to the internal gradient.

Abstract: A system and method which provides simultaneous display of characters on one or more display monitors in multiple languages. The languages can include icon based languages such as Chinese and Japanese or can be traditional character based languages such as romance and Germanic languages. The system includes a main unit having a first memory in which the first memory includes character data stored in a plurality of languages. A portion of the character data in a first language corresponds to another portion of the character data in a second language, the portion of the character data in the first language and the portion of the character data in the second language are stored in the first memory at memory locations having an offset value from each other.

Abstract: A logging-while-drilling density sensor includes a gamma ray source and at least two NaI detectors spaced apart from the source for determining measurements indicative of the formation density. An analytic function based on a heuristic model is used to predict the measured response as a function of offset, mud density and formation density. The model may be used to provide a caliper measurement where acoustic caliper data are unreliable. 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 understand that it will not be used to interpret or limit the scope or meaning of the claims. 37 CFR 1.72(b).

Abstract: Data acquired using a pulsed nuclear source are susceptible to two sources of error. One error is due to large statistical noise towards the end of an acquisition window. Another source of error is the contamination of the early portion of the data by borehole and other effects. The beginning of the processing window is adjusted based on the signal level at the end of the processing window for the preceding pulsing of the source. The end of the processing window is derived from statistical considerations.

Abstract: Method for predicting lithology and porosity of subsurface rocks from seismic reflection data. The seismic data is inverted to yield elastic properties of the rocks such as the compressional and shear impedances. A rock physics model is built to relate porosity, the shale volume fraction, the fluid content of the rock and the elastic properties of the rock. The model is run backward in a second inversion process to solve for porosity and lithologic properties such as the shale volume fraction.

Abstract: The present invention provides a method and apparatus for logging an earth formation and acquiring subsurface information wherein a logging tool is conveyed in borehole to obtain parameters of interest. The parameters of interest obtained may be density, acoustic, magnetic or electrical values as known in the art. The parameters of interest may be transmitted to the surface at a plurality of resolutions using a multi-resolution image compression method. Parameters of interest are formed into a plurality of Cost Functions from which Regions of Interest are determined to resolve characteristics of the Features of interest within the Regions. Feature characteristics may be determined to obtain time or depth positions of bed boundaries and borehole Dip Angle relative to subsurface structures, as well borehole and subsurface structure orientation. Characteristics of the Features include time, depth, and geometries of the subsurface such as structural dip, thickness, and lithologies.

Abstract: Methods and apparatus are provided for determining the content of a first element in a formation which cannot otherwise be determined via a capture spectrum measurement. The methods and apparatus utilize the inelastic spectrum measurement of the first element and the inelastic and capture spectrum measurements of at least a second element. The methods and apparatus have particular application to determining the carbon content of a formation although they are not limited thereto. The inelastic and capture spectrum measurements of silicon are useful in making such determinations, although other chemical elements may be used as the second element.

Abstract: 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.

Abstract: A method of determining the source radiation pattern of at least one source (2) of electromagnetic radiation is provided. The method comprises the steps of at at least one sensor (3), measuring the electric and magnetic fields due to the at least one source; formulating a surface integral over the measured data, the measured data weighted by a Green's function and its spatial derivatives; and evaluating the surface integral at at least one location to determine the source radiation pattern at that location due to the at least one source.

Abstract: A system and method for automated baseline correction for Raman spectra is disclosed which may operate as a piecewise-linear baseline correction function. In an embodiment, a first set of data points from a Raman spectrum are determined to be baseline data points, a second set of data points from the Raman spectrum are determined to be baseline data points where the second set of data points are not contiguous with the first set of data points. The gap between the first and second set of data points is bridged by a straight line thereby forming an estimated baseline. The estimated baseline is smoothed and then subtracted from the Raman spectrum resulting in an adjusted-baseline Raman spectrum.

Abstract: An apparatus for measuring characteristics of earth formations surrounding a borehole, comprises a resistivity measurement device having a multiplicity of antennae spaced between each other in a longitudinal direction of the apparatus. A neutron measurement device of the apparatus comprises at least a neutron source and at least a neutron detector, each of the neutron detectors being at a distance from the neutron source in the longitudinal direction of the apparatus. The multiplicity of antennae are interleaved with the neutron measurement device in order to reduce a total length of the apparatus and in order to allow a determined area of the earth formation to be measured simultaneously using the neutron measurement device and the resistivity measurement device.

Abstract: A gas detection method includes carrying out respective neutron and density logs, using neutron and density detectors, along a length of well. The density log is corrected for the dimensions and properties of the well casing. The corrected density log is then combined with the neutron log to compensate for regions of artificially high density outside the casing. The compensated density log is continuously calibrated against the neutron log. The dynamically calibrated density and neutron logs are inspected for crossovers that signify the presence of gas in a formation.

Abstract: Methods and apparatus are provided for determining the content of a first element in a formation which cannot otherwise be determined via a capture spectrum measurement. The methods and apparatus utilize the inelastic spectrum measurement of the first element and the inelastic and capture spectrum measurements of at least a second element. The methods and apparatus have particular application to determining the carbon content of a formation although they are not limited thereto. The inelastic and capture spectrum measurements of silicon are useful in making such determinations, although other chemical elements may be used as the second element.

Abstract: A method of determining formation density in a cased hole environment using a logging tool having a gamma ray source, a long spacing detector, and a short spacing detector that includes developing one or more cased hole calibration relationships that utilize differences between scattered gamma rays observed by short spacing detectors and scattered gamma rays observed by long spacing detectors to determine corrected formation density values, and using the cased hole calibration relationships and scattered gamma ray measurements obtained by the long spacing detector and the short spacing detector to determine the formation density. An associated article of manufacture and computerized well logging system are also described.

Abstract: 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.

Abstract: A relative dip angle of a deviated borehole is determined from natural gamma ray measurements. Dip corrected measurements are processed to determine the thickness of thin beds, and the peak gamma ray response in thin beds.

Abstract: A method for managing the flow of a plurality of aircraft at an aviation resource, based upon specified data and operational goals pertaining to the aircraft and resource and the control of aircraft arrival fix times at the resource by a system manager, includes the steps of: (a) collecting and storing the specified data and operational goals, (b) processing the specified data to predict an initial arrival fix time for each of the aircraft at the resource, (c) specifying a goal function which is defined in terms of arrival fix times and whose value is a measure of how well the aircraft meet the operational goals based on achieving specified arrival fix times, (d) computing an initial value of the goal function using the predicted initial arrival fix times, (e) utilizing the goal function to identify potential arrival fix times to which the arrival fix times can be changed so as to result in the value of the goal function indicating a higher degree of attainment of the operational goals than that indicated by

Abstract: A method of simply and quickly determining ?-ray releasing nuclides having long half-life without carrying out a chemical separation is provided. By inputting a data of pulses incident to an ?-ray detector in a computer, obtaining time distribution of the incident pulses by using a very short time measuring timer and plotting, and fitting the linear originated in a random event corresponding to the background and the non-linear originated in the correlated events of parent nuclides-progenies by using the least squares method, the whole generating probability P (t) from the parent nuclide to the progeny thereof is obtained. By subtracting the random events portion from the P(t), the correlated events portion is extracted. The radioactivity per unit can be obtained by dividing the extracted correlated events portion by the measured time, the amount of the supplied sample and the counting efficiency.

Abstract: A method and related system of determining formation density by compensating actual inelastic gamma rays detected from a pulsed-neutron tool for the effects of neutron transport. The method and systems may model response of the tool and use the modeled response as an indication of an amount to compensate detected inelastic gamma rays.

Abstract: A method for detecting failures in a natural gas returning radiation from the pipeline; determining that there is a failure in the pipeline when the spectral or thermal signature indicates that there is a plume of escaping natural gas from the pipeline emitted from a failure; and indicating to a customer that a failure in the pipeline has been detected at a predetermined coordinate position.