Abstract: A method of analysing controlled source electromagnetic (CSEM) survey data to determine probability density functions (PDFs) for values of an electromagnetic parameter at locations in a subterranean region of interest is provided. Structural features in the subterranean strata are identified, e.g. from seismic survey data. An initial PDF for values of the electromagnetic parameter is then assigned to each feature. Models lo specifying values for the parameter in each structural feature are generated by sampling the PDFs. A subset of the models are deemed acceptable based on an acceptance criterion. The PDF for each feature is modified based on values for the parameter in the subset of accepted models to generate replacement PDFs for each feature. The process may be iterated a number of times to generate final PDFs for values of the electromagnetic parameter in the structural features identified in the subterranean region of interest.

Abstract: A computer-implemented method is provided that automatically characterizes and verifies stationarity of a training image for use in multipoint geostatistical analysis. The stationarity is preferably characterized by statistical measures of orientation stationarity, scale stationarity, and category distribution stationarity.

Abstract: A method of determining a selection of well measurements and/or their respective control parameters is described based on a global target having predetermined sensitivities to a multitude of uncertainties associated with input variables to a model including the step of ranking measurements and control parameters in accordance with their capability to reduce the uncertainties of input variables identified as most sensitive input variables through simulations using the model or a reduced variant of the model.

Abstract: A method for managing information associated with an oilfield operation of an oilfield, the oilfield having a subterranean formation with geological structures and reservoirs therein. The method includes specifying a first site of interest, where a first data source includes data stored at the first site of interest, designating a first abstract role for the first data source, where the first abstract role corresponds to one of a plurality of information lifecycle roles, designating a first abstract stream for the first data source, where the first abstract stream corresponds to one of a plurality of categories of information, and generating a first output associated with the first data source, where the first output includes the first site of interest, the first abstract role, and the first abstract stream. The method further includes presenting the first output, where the oilfield operation is adjusted based on the first output.

Abstract: Borehole images obtained with MWD measurements have a mismatch with subsequent images obtained when measurements are repeated over the same depth interval after the drillstring has been raised up. The difference is attributable to stretch of the drillstring. This can be estimated by correlating the two images. The difference can also be estimated by monitoring drilling conditions such as RPM, WOB and torque on reentry.

Abstract: Methods for determining the distance and relative axial position between twin and target wells are disclosed. In one exemplary embodiment the magnitude and direction of the interference magnetic field vector are processed to determine the distance and the axial position. In another exemplary embodiment, a change in direction of the interference magnetic field vector between first and second longitudinally spaced magnetic field measurements may be processed to determine the distance and axial position. In still another exemplary embodiment of the invention, a component of the magnetic field vector aligned with the tool axis may be measured in substantially real time during drilling and utilized to determine the distance between the two wells. Embodiments of this invention improve the accuracy and/or the frequency of distance determination between twin and target wells.

Abstract: A method for simulating flows in reservoirs, such as hydrocarbons, by means of chimera type grid which fluid generates a chimera grid made up of a set of elementary grids for accounting for characteristics of the flows and of the geometry (e.g., radial grid in the well zone and CPG grid for the reservoir) so that their union covers the entire simulation domain and that there is a minimum overlap between two neighboring elementary grids. Interpolation parameters allowing connection of the flows calculated on the grid to the flows calculated on the neighboring grids are then determined on the border of each elementary grid. Finally, flows are simulated within the reservoir and the well, and the variables describing the flow on the border of the overlap zones are interpolated using the interpolation parameters.

Abstract: A method and system for estimating reservoir pressure in a hydrocarbon reservoir from downhole pressure measurements of producing wells is disclosed. Pressure measurements are obtained from wells in the production field over time, and communicated to a server that applies the pressure measurements for a well to a model of that well. The server operates the model using the pressure measurements to determine an operating mode of the well, such as producing or shut-in. Upon detection of a change in operating mode indicative of an abrupt change in flow at the well, such as corresponding to a shut-in event, additional downhole pressure measurement data is acquired until a steady-state condition is reached. The pressure measurements are used to determine a reservoir pressure, which is transmitted to a responsible reservoir engineer or other user. Modification of the determined reservoir pressure value by the user can be received, and the stored reservoir pressure and well model are updated accordingly.

Abstract: A method of deriving a calibration filter for electromagnetic data is provided. The method comprises providing a source (21, 22) of electromagnetic radiation and subsequently measuring components of the source electromagnetic field (23, 24, 25) at a receiver when the source is sufficiently close to the receiver that the down-going signal dominates over the up-going signal reflected from features below the receiver. Such a measurement can be used in frequency domain analysis (26, 28, 29) to extract the down-going signal component and derive a calibration filter for the receiver. The method is repeated (27, 30) for each receiver used in an electromagnetic sounding survey.

Abstract: Wellbore tracking by developing a wellbore deviation survey, including collecting wellbore deformation data using a caliper at each of a plurality of depths within the wellbore, collecting wellbore deviation data using a tiltmeter at ones of the plurality of depths, determining simulated wellbore deformation and deviation data using the oriented wellbore deformation data, and developing a wellbore deviation survey by calibrating the wellbore deviation data based on the oriented wellbore deviation data.

Abstract: A method of oilfield data management including collecting oilfield data from an oilfield, executing instructions on a processor to perform a domain analysis of the oilfield data by a first analysis team to generate a first analysis, the first analysis team comprising a plurality of users who analyze a portion of the oilfield data relating to one or more oilfield functions, selectively providing access to the first analysis and the portion of the oilfield data for the plurality of users based on a continued analysis of the oilfield, executing instructions on the processor to perform the domain analysis of the oilfield data by a second analysis team to generate a second analysis, the second analysis team analyzing the portion of the oilfield data relating to the one or more oilfield functions, and selectively synchronizing the first analysis and the second analysis to generate a synchronized result.

Abstract: Methods, computer programs, and systems for detecting at least one downhole condition are disclosed. Forces are measured at a plurality of locations along the drillstring. The drillstring includes a drillpipe. At least one of the forces is measured along the drillpipe. At least one downhole condition is detected based, at least in part, on at least one measured force.

Abstract: A method for mapping a complex sedimentary basin is disclosed. A grid representative of the current architecture of the basin is constructed. A mechanical structural restoration is applied in three dimensions so as to reconstruct the past architectures of the basin from the current time up to a geological time t. A simulation of the geological and geochemical processes that govern the formation of a petroleum reservoir is then carried out, directly in the grids obtained from the restoration, from the geological time t to the current one. This simulation is thereafter used for mapping the sedimentary basin so as to identify zones of the basin where hydrocarbons may have accumulated.

Abstract: A method to determine formation properties using two or more data sets in which the solutions corresponding to the data sets represent shared and distinct formation properties. The method analyzes the data sets and computes distributions for the shared and distinct formation properties from which the formation properties are determined.

Abstract: The present invention is a method of determining fluid phase distribution and quantifying holdup in a wellbore. The method includes receiving a plurality of oriented probe data and grouping the oriented probe data based on a depth interval. The grouped probe data is processed and fluid phase distribution information is generated based on the processed result.

Abstract: A visualization system for a wellbore environment includes a graphics processor for creating a wire mesh model of a well and optionally a drillstring based on datasets of depth-varying parameters of the well. A graphics system maps appropriate textures to the wire mesh models, which are then displayed on a graphics display. A user interface facilitates user navigation along the length of the well to any selected location therein, and further permits user adjustment of orientation of the displayed renderings. Simulated, real or a combination of simulated and real wellbore data may be visually depicted in the wellbore at any selected location. This provides the user with a visual indication of the wellbore environment as the user navigates the visualization along the length of the wellbore.

Abstract: A method for estimating a shape, the method including: selecting a structure comprising a plurality of strain sensors inoperable communication with the structure, each strain sensor configured to provide a strain measurement; placing the structure in a borehole; receiving the strain measurements from the plurality of strain sensors; creating a mesh grid having nodes, each node related to a location of one strain sensor and assigned a strain value measured by the one strain sensor; creating an additional node for the mesh grid wherein a strain value assigned to the additional node is derived from the strain value corresponding to at least one adjacent node; and performing an inverse finite method using the mesh grid with the assigned strain values to estimate the shape.

Abstract: A device and method can detect, and also break, an occurrence of gas lock in an electrical submersible pump assembly in a well bore based upon surface or downhole data without the need for operator intervention. To detect an occurrence of gas lock, an instantaneous value is monitored using a sensor. Then a controller compares the instantaneous value to a threshold value over a predetermined duration to thereby detect the occurrence of gas lock in the electrical submersible pump assembly. Sensors can include, for example, a differential pressure gauge, a pressure gage located in a pump stage located toward the inlet, a fluid temperature sensor located toward the discharge, a free gas detector located near the pump discharge, an electrical resistivity gage, a flow meter located within surface production tubing, and a vibration sensor attached to a tubing string to measure a vibration signature.

Abstract: Various technologies for removing shoulder-bed effects from measurements of an earth formation made in a wellbore. In one implementation, a methodology for removing the shoulder-bed effects includes receiving the measurements and constructing a layered model of the earth formation. Each layer has a set of parameters corresponding to one or more types of the received measurements ascribed to each layer such that the set of parameters define a parameter space for the layered model. The methodology may further include dividing the parameter space into subspaces based on relationships among the parameters, selecting from the subspaces one or more starting points, minimizing a cost function using the one or more starting points to generate one or more candidate solutions having the shoulder-bed effects removed and selecting a final solution from the one or more candidate solutions.

Abstract: A method of hydrodynamics-based gridding (Hydro-Grids) for creating geologic models of subsurface volumes, such as reservoirs, is disclosed. Geologic data is obtained. Vertical grid surfaces are created. Lateral grid surfaces are created to correspond to surfaces of constant geologic time during the deposition of sediments in the subsurface volume. Geologic properties within each cell are represented as values within each cell created by the vertical and lateral surfaces. Reservoir performance is simulated using the represented geologic properties of the subsurface volume. A hydrocarbon reservoir is developed based on the simulated reservoir performance.

Abstract: This invention relates in general to measuring depth of well-tools, such as logging tools or the like, in a borehole. Embodiments of the present invention may provide for disposing conducting areas along a wireline that may be used to suspend and move the well-tool in the borehole, where the conducting areas may be disposed along the wireline at predetermined locations. A reader may be located at a reference location and may read when a conducting area passes through the reference location and this information may be used to determine the depth of the well-tool in the borehole. Additionally, this invention provides for combining depth measurements from the conducting areas with measurements from odometer wheels in frictional contact with the wireline and/or time of flight measurements of optical pulses passed along a fiber optic cable coupled with the wireline to accurately and robustly measure the depth of the wireline in the borehole.

Abstract: The present invention provides an easy, field applicable, and extra-equipment method for determining steam dryness directly under thermal high-viscosity oil stimulation. The technical effect is achieved by adding the gas non-condensed in a well under flooding to the saturated steam pumpdown. The non-condensed gas occurrence of the mixture will vary partial steam pressure. In doing so, the steam condensation temperature will vary too. The borehole temperature or pressure measurements can be used to evaluate the steam dryness.

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: A visualization system for a wellbore environment includes a graphics processor for creating a computer rendered visual model of a well, and optionally a drill string, based on data sets of depth-varying and/or time-varying parameters of the well. The model is then displayed on a graphics display. A user interface facilitates user navigation along the length of the well to any selected region therein, and further permits user adjustment of orientation of the displayed renderings as well as a temporal selection of the time-varying data to be displayed. Simulated, real, or a combination of simulated and real wellbore data, which may be steady state, transient, or real-time data, may be visually depicted at any selected region. This provides the user with a visual indication of the wellbore environment as the user navigates the visualization spatially and temporally.

Abstract: A system for measuring a true vertical depth of a downhole tool is provided. The system includes: a first optical clock located at a first depth and having a first frequency; a second optical clock disposable at a downhole location and having a second frequency at the downhole location; and a processor for receiving the first frequency and the second frequency, and calculating a true vertical depth of the second optical clock based on a difference between the first frequency and the second frequency. A system and computer program product for measuring a true vertical depth of a downhole tool are also provided.

Abstract: A method, apparatus and computer program for improving the signal-to-noise ratio of a signal S(t), S(t) containing Signal and noise, are disclosed. A measurement of S(t) at a frequency-of-interest is obtained. Noise measurements of S(t) at one or more noise frequencies where the Signal portion of S(t) is expected to be small are obtained. The noise at the frequency-of-interest is estimated using the noise measurements at the one or more noise frequencies. The estimated noise is subtracted from the measurement of S(t) at the frequency-of-interest.

Abstract: The invention includes a method for determining a steam injection schedule for a set of subsurface formation subsurface regions of an oil field, the method including the steps of determining a thermal maturity for each subsurface region of the set; calculating a latent beat target for each subsurface region according to the determined thermal maturity therefore; calculating a steam injection target for each subsurface region according to the calculated latent heat target therefore; determining the availability of steam for injection to the subsurface regions; and calculating a steam injection schedule for each subsurface region according to the determined steam availability and calculated steam injection targets for all subsurface regions of the set.

Abstract: An instrument, such as a wall-thickness, rod-wear, or pitting sensor, can monitor tubing as a field service crew extracts the tubing from an oil well or inserts the tubing into the well. A digital system can process data from the instrument to improve the data's fidelity, quality, or usefulness. Digital signal processing can comprise filtering or otherwise manipulating the data to provide refined data that a person or machine can readily interpret. For example, a graphical representation of the refined data can help an operator evaluate whether a segment of tubing is fit for continued service. Processing tubing data can comprise applying a flexible level of filtering, smoothing, or averaging to the data, wherein the level changes based on a criterion or according to a rule. The level can vary in response to a change in tubing speed, noise in the raw data, or some other parameter.

Abstract: To characterize an electrical cable that is deployed in a well, a voltage input is applied to the electrical cable at an earth surface location, where the well extends from the earth surface location. A current response resulting from the voltage input is measured at the earth surface location. At least one parameter of the electrical cable is computed according to the measured current response.

Abstract: Seismic data may be imaged using or recognizing substantially only primary reflections. Imaging seismic data may include for example integrating a plurality of seismic data points that have substantially similar arrival directions, for example, to a modeled primary ray. Seismic data points may be imaged that for example substantially meet a set of predetermined conditions, for example, conditions substantially unique to primaries, which may include for example arrival direction and angle of reflection.

Abstract: Disclosed herein is a method of locating and quantifying friction between a drillstring and a wellbore. The method includes, positioning a plurality of sensors within a wellbore, communicatively coupling the plurality of sensors, monitoring signals from the plurality of sensors, logging the sensed signals versus time versus depth of each of the plurality of sensors, locating at least one friction zone along the drillstring within the wellbore based on the logging and quantifying friction in the at least one friction zone based on the logging.

Abstract: A method for determining properties of a subterranean formation. The method includes determining at least one characterization parameter based on wave velocity measurement data, determining a plurality of elastic coefficients based on the at least one characterization parameter using a plurality of equations, determining an anisotropic stress profile of the subterranean formations based on the stiffness matrix of the subterranean formation comprising the plurality of elastic coefficients wherein the elastic coefficients are approximated using the plurality of equations, and displaying the anisotropic stress profile of the subterranean formations.

Abstract: A first NMR echo train is acquired with a single TE. A second NMR echo train is acquired with a first portion having the same TE and the second portion having a longer TE. When measurements are made with a low magnetic field gradient, processing the two echo trains can be used to determine gas in the formation.

Abstract: A method for detecting a change in a wellbore fluid includes estimating at least two pressure differences in the wellbore fluid and estimating a change in a density of the fluid using the at least two pressure differences. The density change may be estimated by the equation, ??=(?Pbefore—influx??Pafter—influx)/(g×?TVD), wherein ?P is a fluid pressure difference between two points along the wellbore, ? is a mean value of density of the fluid between the two points, g is gravity and ?TVD is a vertical distance between the two points. The method may include estimating a density change using an estimated inclination of the wellbore. An apparatus for estimating density changes includes at least two axially spaced apart pressure sensors. The sensor positions may be switched to estimate a correction term to reduce a relative offset between the two pressure sensors.

Abstract: A method for characterizing a fractured wellbore involves obtaining static data and production data from the fractured wellbore, integrating the static data and the production data using Bayes's theorem, and calculating a plurality of model parameters from Bayes's theorem, where the plurality of model parameters is used to alter completion of the fractured wellbore.

Abstract: A digital signal representative of a difference in pressure is received from a differential pressure transmitter. A noise signal is obtained by processing the signal through a band pass filter or otherwise to provide a filtered noise signal. Absolute values of the filtered noise signal are calculated and compared to one or more predetermined threshold values to determine if one or more impulse lines are plugged. A training mode is used to determine the thresholds, which may be a function of flow rate and other flow conditions.

Abstract: Pump noise in a mud-pulse telemetry system is reduced based on analysis of the frequency characteristics of the noise generated by one or more pumps. Least mean-squares filtering may be done. Alternatively, the frequency domain analysis of the pump frequencies is fine-tuned in the time domain and a synthetic timing signal is used for the filtering.

Abstract: A method for determining a location and characterization of an object using a magnetic gradient tensor measurement of the object is provided. The method includes determining an object magnetic field candidate predicted from one of an object measured magnetic field gradient and an assumed object magnetic moment magnitude, and determining an object vector location and an object vector magnetic moment by combining the object magnetic field candidate with an object measured magnetic field.

Abstract: A method for magnetizing a wellbore tubular is disclosed. The method includes magnetizing a wellbore tubular at three or more discrete locations on the tubular. In exemplary embodiments the magnetized wellbore tubular includes at least one pair of opposing magnetic poles located between longitudinally opposed ends of the tubular. Wellbore tubulars magnetized in accordance with this invention may be coupled to one another to provide a magnetic profile about a section of a casing string. Passive ranging measurements of the magnetic field about the casing string may be utilized to survey and guide drilling of a twin well. Such an approach advantageously obviates the need for simultaneous access to both wells.

Abstract: A method for assessing health and performance of a system. In one example, the system comprises subsystems (preferably physically coupled subsystems), at least some of which are characterizable by transmitted signals. Some of these signals are transformed into a comparable form and compared, so as to identify signals that are outside of operating bounds.

Abstract: An instrument, such as a wall-thickness, rod-wear, or pitting sensor, can monitor tubing as a field service crew extracts the tubing from an oil well or inserts the tubing into the well. A computer-based system can process data from the instrument to evaluate the validity of the data. Validating the data can comprise determining whether any features, structures, or patterns present in the data correlate with actual tubing defects or were caused by a condition unrelated to tubing quality, such as signal noise. The computer-based system can also analyze the data to deduce information about the performance of the well or to determine the well's operating state or status. For example, the data analysis can determine whether the well's fluids have a chemical condition that should be treated or whether a detrimental harmonic oscillation has been occurring in the well's mechanical pumping system.

Abstract: Method, system and computer program product for controlling a production/injection operation for an oilfield, the oilfield having a first wellsite with a producing well advanced into subterranean formations with geological structures and reservoirs therein. Data from a plurality of data sources is collected with respect to a production/injection operation, wherein the collected data includes oil production data and fluid injection data. The collected data is stored in a database. Extracted data relating to a selected performance parameter to be monitored is extracted from the database, the extracted data is processed, and a graphical representation of the processed data is dynamically displayed to enable monitoring of the selected performance parameter.

Abstract: Borehole image data is compressed and transmitted to the surface one pixilated trace at a time. The compression methodology typically includes transform, quantization, and entropy encoding steps. The invention advantageously provides for sufficient data compression to enable conventional telemetry techniques (e.g., mud pulse telemetry) to be utilized for transmitting borehole images to the surface. By compressing and transmitting sensor data trace by trace the invention also tends to significantly reduce latency.

Abstract: Measurements made with an induction logging tool are processed to provide a resistivity model of fluid invasion of the formation. Up to five zones can be determined over a radial distance of about 0.6 m. 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: A time measurement device for a geologic downhole measurement tool is provided. The device includes a plurality of oscillators for measuring a time value. At least one of the plurality of oscillators has a first temperature range that is different from a second temperature range of at least another of the plurality of oscillators. A time measurement system and a method for providing a time measurement are also provided.

Abstract: A technique includes receiving a first dataset that is indicative of seismic data acquired in a seismic survey of a field of wells and receiving a second dataset that is indicative of wellbore data acquired in a wellbore survey conducted in at least one of the wells. The technique includes determining a mechanical earth model for the field based at least in part on the seismic data and the wellbore data.

Abstract: Characterizing a reservoir with electromagnetic imaging surveys includes normalizing measured voltage data by transmitter moment, sorting the normalized voltage data into common receiver profiles, densely resampling transmitter locations using common positions for the receiver profiles, coarsely resampling the data at discreet transmitter locations, defining a starting model for inversion, weighting the data by a factor, converting the normalized voltage data to ratios, calculating a conductivity image using a ratio inversion method, and verifying that an inversion has converged and the image is geologically reasonable. The image can then be displayed. The invention can be used for cross-well, surface-to-borehole, and borehole-to-surface measurements by which the effects of steel casing are reduced.

Abstract: A simulation system includes a case manager adapted for organizing and managing a plurality of sets of input data being used by the simulation system. The case manager includes a plurality of case scenarios organized in a tree-like structure, some case scenarios being supersets of other case scenarios in the tree-like structure. An operator selects one or more of the case scenarios in the case manager. A case builder receives keywords associated with the one or more of the case scenarios selected by the operator allowing the operator to edit or change the keywords from the selected case scenarios when necessary and generates a set of edited keywords representing edited case scenarios. A run manager submits the edited case scenarios to a simulator which generates a set of simulation results that are stored in a results file for subsequent display and viewing.

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 for forming a borehole image of an azimuthally sensitive borehole or formation parameter is disclosed. Such a borehole image may be formed, for example, by processing logging sensor data with a predetermined sensor response function (also referred to herein as a probability density function) to acquire probabilistically distributed sensor data. The sensor data may be distributed in either one-dimension (azimuthal) or two-dimensions (azimuthal and axial). Certain embodiments of this invention may be advantageously utilized in LWD imaging applications and provide for superior image resolution and noise rejection as compared to prior art binning techniques. Exemplary embodiments of the invention also advantageously conserve logging sensor data such that integration of the distributed data over the entire circumference of the tool provides a non-azimuthally sensitive logging measurement.