Abstract: The invention provides a method and apparatus for use in testing the swell characteristics of swellable components used in downhole exploration or production equipment, such as swellable packers. A method of measuring a test piece using a testing apparatus with a fluid chamber and a transducer is described. Measured data can be compared with data measured from a sample section of a tool to determine a relationship between swell characteristics. The determined relationships can then be used to calculate or predict swelling characteristics of swellable components, for example particular packer designs, in specific fluid samples.

Abstract: A method for removing the effects of an airwave from marine electromagnetic data comprising providing an electromagnetic source and at least one receiver in the water; measuring the electromagnetic response at a first source-receiver separation; determining a scaled version of the airwave response at a source-receiver separation where the earth response is negligible and using the scaled airwave response to determine the earth response measured at the first separation. Using this method, an improved estimate of the earth's response can be achieved.

Abstract: A computer-implemented method and system for processing subsurface logs to enhance the continuity of physical property measurements. The method includes obtaining a set of measurement signals along a spatial or time domain from at least one sensor tool moving through a borehole which has traversed through a subsurface region. The method additionally includes performing a global inversion of the set of measurement signals along the spatial or time domain to determine a set of physical properties of the subsurface region having a smooth variation along the spatial or time domain, wherein the set of physical properties can be utilized to determine characteristics of the subsurface region.

Abstract: A method and system is provided for determining the value of an attribute of ambient energy at a drilling assembly at the bottom of a borehole. Ambient energy includes kinetic energy, hydraulic energy and thermal energy. Attributes include vibration frequency spectrum, pressure difference, and temperature difference. The method uses energy harvested by at least one energy-harvesting sensor to power the system. The system generates data signals from at least one energy-harvesting sensor at one or more locations along a downhole drilling assembly, and transmits data up the borehole.

Abstract: A method for determining in-situ relationships between physical properties of a porous medium from a sample thereof includes acquiring a three-dimensional image of the sample and segmenting the image into pixels representing pore space and pixels representing rock grain. A plurality of sub-volumes are selected from the segmented image, and a porosity is calculated for each of the sub-volumes. A digital simulation is conducted on each of the sub-volumes to obtain a selected physical property for the sub-volume. A relationship is determined between porosity and the selected physical property using relationship data comprising the calculated porosity and the simulated physical property for each of the sub-volumes. The method includes at least one of storing and displaying the relationship.

Abstract: An exemplary system for managing the deployment of a seismic data acquisition system uses a module configured to execute a plurality of task in the field by receiving one or more seismic devices. The module may include a power source that provides electrical power to the seismic devices. The module may also include a processor programmed to retrieve data stored in the seismic devices, perform diagnostics, facilitate inventory and logistics control, configure seismic devices and update data or pre-programmed instructions in the seismic device.

Abstract: According to a first preferred aspect of the instant invention, there is provided an efficient method of computing a 3D frequency domain waveform inversion based on 3D time domain modeling. In the preferred arrangement, 3D frequency domain wavefields are computed using 3D time-domain modeling and a discrete Fourier transformation that is preferably computed “on the fly” instead of solving the large systems of linear equations that have traditionally been required by direct frequency domain modeling. The instant invention makes use of the theory of gradient-based waveform inversion that estimates model parameters (for example velocities) by matching modeled data to field data sets. Preferably the modeled data are calculated using a forward modeling algorithm.

Abstract: Aspects of this invention include methods for surveying a subterranean borehole. In one exemplary aspect, a change in borehole azimuth between first and second longitudinally spaced gravity measurement sensors may be determined directly from gravity measurements made by the sensors and a measured angular position between the sensors. The gravity measurement sensors are typically disposed to rotate freely with respect to one another about a longitudinal axis of the borehole. Gravity MWD measurements in accordance with the present invention may be advantageously made without imposing any relative rotational constraints on first and second gravity sensor sets. The present invention also advantageously provides for downhole processing of the change in azimuth between the first and second gravity sensor sets. As such, Gravity MWD measurements in accordance with this invention may be advantageously utilized in closed-loop steering control methods.

Abstract: In an exemplary embodiment, a method and system is disclosed for developing a subterranean geomechanics model of a complex geological environment. The method can include estimating a pore pressure field, a stress field, a geomechanics property field, and a geological structure field from a geological concept model; geostatistically interpolating vectors and tensors from the estimated fields; and combining the results from the estimated fields and the geostatistically interpolated vectors and tensors to derive a geostatistical geomechanical model of the geological environment.

Abstract: A method is disclosed for modeling a reservoir, comprising: receiving a set of wettability logs from a wettability logging tool adapted to be disposed in a wellbore; generating a wettability map in response to the wettability logs; generating a gridded simulation model, the gridded simulation model including a plurality of grid cells; determining, for each grid cell of the gridded simulation model, a local value of wettability from the wettability map; determining, for each grid cell of the gridded simulation model, a permeability model and a capillary pressure model from the local value of wettability associated with each grid cell; and generating a set of simulation results representing characteristics of the reservoir.

Abstract: It is shown that a pressure pulse originating in a well is correlated to a pulse observed at a distant well with a characteristic time. The correlation time is directly related to the diffusion time scale arising out of the pressure diffusion equation. The relationship is affected by the source-observer or observer-observer distance but the correction is small for large distances. In practice, further corrections have to be included for finite width pulses. For these pulses, a practical scheme for continuous permeability monitoring is presented.

Abstract: A while-drilling Vertical Seismic Profiling (VSP) data acquisition system utilizing the same seismic shots for three purposes is disclosed. First, the seismic shots provide a means for synchronizing a downhole clock in the VSP receiver to a master clock at the surface, thereby enabling correct determination of seismic travel times. Second, the same seismic shots are also used to communicate commands and other information to the downhole VSP receiver, such commands controlling the actions of the VSP receiver or associated devices. Third, the same seismic shots are utilized for purposes of the VSP survey itself, i.e. determination of seismic travel times, forming of seismic images, and determination of geologic and formation fluid properties using the VSP methods.

Abstract: A fluids lifting tool and analysis system. The present invention comprises a fluid lifting system for a gas well. The system comprises a lifting tool positioned in the well and a docking station at the well surface. The tool includes a processor, pressure sensors, temperature sensors, an accelerometer, and a proximity sensor. A battery in the tool is adapted to be charged by inductive coupling using coils in the docking station and the tool. The tool is released from the docking station and descends the well. During descent the tool measures elapsed time, velocity of the tool, calculates distance traveled, measures pressure and temperature, determines volumes or oil and water in the well, and senses when the tool reaches the bottom of the well. The FLT chooses to ascend the well when appropriate and transfers measured and calculated data to the docking station.

Abstract: A method for estimating a temperature within sub-surface materials traversed by a wellbore includes: obtaining temperature data from a plurality of measurements of temperature taken within the wellbore; calculating an overall heat transfer coefficient from the measurement data; calculating a geothermal gradient from the overall heat transfer coefficient; and using the geothermal gradient to estimate the temperature within the sub-surface materials. A system and a computer program product are provided.

Abstract: A method and apparatus for testing a blowout preventer (BOP) wherein a pressurization unit applies fluid to an isolated portion of the throughbore of the BOP. A signal that is representative of the actual pressure in the isolated portion of the throughbore over successive time points and a pre-determined non-deterministic finite state automaton are used to predict the pressure in the isolated portion of the throughbore as a function of time relative to a pre-determined acceptable leak rate and the time at which stability is achieved. In one embodiment stability is achieved when successive predicted pressures are within a predetermined difference over a predetermined interval of time. Visual indications are provided to depict the progress of testing.

Abstract: A method is disclosed of enhancing one or more attributes of a log, of a geological formation, including data generated in plural measurement channels corresponding to plural measurement devices, the method comprising the steps of: selecting data corresponding to a single said channel and deconvolving it; and seeking to impose one or more attributes of the resulting deconvolved data onto convolved log data of plural said channels in order to create an enhanced log.

Abstract: The invention relates generally to the field of oil and gas exploration and specifically to the use of well logs for exploration. This invention is directed to a method for estimating data that would have been collected in a region of a well log where there is a gap. This method uses identified elements in one data set to identify elements in another data set with data values indicative of the same geological characteristic as those in the first data set.

Abstract: Systems and methods of enhancing crude oil recovery include radiating electromagnetic energy in the form of focused electromagnetic pulses into a permeable formation containing the crude oil and/or fluid via an array of antennae transmitting immediately in the far field. The electromagnetic pulses are focused at the depth of the fluid reservoir. Pulses will be reflected by the fluid according to the fluid material (e.g. oil vs. water) and/or the strata (e.g. rock, sand, etc.). An array of receiver antennae may be used to initially establish a reference of the reflected electromagnetic pattern, and then operated in conjunction with the transmit array to monitor the relative horizontal movement of oil and/or water within the subterranean reservoir.

Abstract: A method for estimating an impedance of a material behind a casing wall in a borehole, the method comprises exciting the casing wall with an acoustic pulse, and measuring by means of a transducer an experimental acoustic waveform (W) reflected from the casing wall. The method further comprises initializing an impedance parameter (Zin), computing an inverse casing response (Rcas?1) as a function of the impedance parameter (Zin) and a casing thickness parameter (Casin), and deconvoluting the experimental acoustic waveform with the inverse casing response to obtain a transducer response (T). An iterative loop is performed, comprising the computing of an inverse casing response and the deconvoluting of the experimental acoustic waveform by varying the impedance parameter until the transducer response becomes compact in the time domain. The estimated impedance (Zcem) is obtained from the impedance parameter when the transducer response is compact.

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: A method and apparatus for determining an effective cross-sectional area of a borehole including one or more sources for generating tube or Stoneley waves in the borehole; receivers for measuring amplitudes of the waves; and means to relate said measured amplitudes to said effective cross-sectional area or related parameters.

Abstract: A method for data processing includes transforming measurement data acquired in the time domain during an oilfield operation into a second domain to produce transformed data; identifying distortions in the transformed data; removing the distortions from the transformed data; and transforming back from the second domain to the time domain to produce cleaned-up data. The transforming measurement data may use a Fourier transform or a wavelet transform. The method may further include compressing the cleaned-up data or reconstructing signals from the cleaned-up data. A method for data processing includes decomposing measurement data, which are acquired in an oilfield operation, using a low pass filter to produce a first dataset; decomposing the measurement data using a high pass filter to produce a second dataset; removing distortions from the second dataset to yield a corrected second dataset; and reconstructing a corrected dataset from the first dataset and the corrected second dataset.

Abstract: A method and system of detecting and mapping a subsurface hydrocarbon reservoir includes determining ratio data for a plurality of orthogonal spectral components of naturally occurring low frequency background seismic data. The ratio data may be compared, plotted, contoured and displayed as a subsurface hydrocarbon reservoir map or a hydrocarbon potential map. The ratio data may represent a vertical spectral component of the seismic data over a horizontal spectral component of the seismic data. The subsurface hydrocarbon reservoir map may include contouring the ratio data over a geographical area associated with the seismic data.

Abstract: A method for updating a software of a sub-sea controller (31) located under the sea level. The sub-sea controller manages a plurality of tools in a sub-sea well. An application module (35) is downloaded into the sub-sea controller. The application module is executed using a virtual machine (36) implemented within the sub-sea controller.

Abstract: A system and method enable testing of a plurality of well-logging tools on a common, realistic earth model. To enable this testing, a model of a synthetic virtual geologic volume of interest is generated. From the synthetic virtual geologic volume of interest, a plurality of test properties are determined as a function of position within the virtual geologic volume of interest, wherein the test properties are measurable in actual geologic volumes of interest by a well-logging instruments. The individual test properties are then distributed to well-logging instrument developers with the model of the synthetic virtual geologic volume of interest to enable modeling and/or benchmarking of different well-logging instruments on the synthetic virtual geologic volume of interest and the ability to derive the original formation properties regardless of the method used (inversion, analytical solution, etc.).

Abstract: Dispersive array acoustic data are acquired. A histogram is determined from the semblance-frequency coherence of the data. The low frequency limit of the data is estimated by matching the statistics of the histogram to the statistics of a modeling function.

Abstract: There is provided a method of processing geological data during drilling of a borehole for improving accuracy of the geological data. The method includes a first step of determining from instrumentation (100) associated with a string (50) of drilling pipes a spatial trajectory of a borehole (20, 200) in a subterranean region. A second step of the method involves determining from the spatial trajectory one or more points (P1, P2, P3) with reference to the geological data whereat the trajectory changes direction in one or more layers of strata (F) of the subterranean region. A third step of the method involves subdividing an offset log generated by the instrumentation (100) in response to the one or more points (P1, P2, P3) to generate corresponding sections of offset log. A fourth step involves mutually comparing the subdivided sections of offset log to find a condition of best comparison therebetween and thereby generate one or more error terms (E).

Abstract: A method and computer program product of either preventing or minimizing pore pressure increase near the wellbore wall within argillaceous formations through which a borehole has been drilled. By interpreting relevant drilling experience data, the type, extent and time-dependency of wellbore instability mechanisms are determined. The impact of drilling mud designs on the time-dependent wellbore instability and hole enlargement is determined by back-analyzing observed drilling events. At least one field-based criterion relationship between net mud weight reduction percentage ratio and hole enlargement is determined. A maximum allowable percentage ratio(s) of net mud weight reduction and either breakout mud weight or mud weight used for the adopted maximum hole enlargement that the wellbore may experience during drilling is determined. Drilling mud salinity value and salt type to satisfy maximum allowable percentage ratio(s) is then determined.

Abstract: Using an electromagnetic logging tool, desired antenna responses are synthesized from a combination of measured antenna responses, as well as antenna arrays particularly suited to provide the measurements. Those arrays may include cross dipole and double cross dipole antennas. Direct and derivative responses are used to synthesize the desired response, and the synthesized desired response is used to determine formation properties.

Abstract: A computer-based system analyzes reservoir simulation results with a rule-based event monitor to trigger appropriate warnings in the event any of a number of applicable reservoir operation conditions is detected as likely to occur. The conditions may be automatically analyzed on multi-dimensional data during successive time steps to detect events indicated as needing attention or analysis and thus to alert reservoir engineers about operating conditions in the reservoir so that the engineers may make appropriate operational or simulation changes. The conditions may also be automatically analyzed in a batch processing mode of a set or subset of available time steps to detect and generate a log of events encountered that are indicated as needing attention or analysis.

Abstract: A new method for assessing the probability of production at a wellsite. The process includes the four steps of: 1) Data Collection and Uncertainty Analysis; 2) Wellsite Preparation; 3) Treatment Selection/Job Execution; and 4) Evaluation and Upscaling to Field Level.

Abstract: The invention relates to a method for predicting zonal productivity of an oilfield drilling operation. The method includes acquiring critical drawdown pressure profile (CDPP) of at least one selected from a group consisting of an open well and a cased well, establishing a CDPP criteria according to geomechanics based model, identifying sand failure according to the CDPP criteria, and predicting zonal productivity of a drilling operation according to the sand failure.

Abstract: A visualization system for wellbore and drillstring data includes a graphics processor for creating a wire mesh model of a well and 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. The data is sufficient to permit calculation of fluid velocity in the wellbore at any selected location. The fluid velocity is presented as a velocity profile in the rendered visualization of the wellbore and drillstring to provide the user with a visual indication of fluid velocity in the wellbore as the user navigates the visualization along the length of the wellbore and drillstring.

Abstract: A method, apparatus and computer-readable medium for evaluating an earth formation includes making measurements with a logging tool having a first depth of investigation in a borehole in the earth formation. A first dip of the formation is estimated using multi-component measurements. The estimated dip is compared with a second dip measurement in the borehole. The results of the comparison are stored on a tangible medium.

Abstract: A method of constraining a stochastic model of Gaussian or related type, representing a porous medium such as an underground reservoir, to data characteristic of the displacement of the fluids is disclosed. The method is based on an iterative development in two stages. The first stage carries out a flow simulation, in identifying zones inside the reservoir and in estimating the modification to be brought to the effective permeabilities of these zones so as to improve calibration between the real data and the corresponding responses obtained with the flow simulator. The second stage involves an intermediate optimization problem intended to minimize an intermediate objective function (implemented from a gradual deformation technique) measuring the difference between the effective permeabilities calculated for the zones and the effective permeabilities identified during the first stage for better calibration.

Abstract: The present invention is directed to methods for an off-site supervisor or well owner to evaluate the rig load data provided by a well service rig at a well site by evaluating charts of sensor data obtained from sensors on or associated with the well service rig. A rig load data chart can be reviewed and activities completed by the rig identified based on the data curves on the rig load data chart. In addition the hook load carried by the service rig can be determined by evaluating the rig load data charts of sensor data. Furthermore, well bore and tubing conditions in the well can be analyzed based on the rig load data in the rig load data charts while tubing and rods are being pulled from the well or well bore.

Abstract: Predicting sand production in a wellbore. A first set of characteristics is determined for a formation in the wellbore, wherein determining uses a plastic model of the formation, and wherein the first set of characteristics comprises a yield surface, a failure surface, a stress total strain, an elastic strain, and a plastic-strain relationship. A relationship among a second set of characteristics of the wellbore is determined using an effective stress model, wherein the second set comprises a drawdown pressure, a production rate, pore pressure, a temperature and a viscosity of a fluid in the wellbore, a fluid flow pressure in the wellbore, a drag force of fluid flow in the wellbore, and a type of fluid flow in the wellbore. A critical total strain is determined for the formation using the first set of characteristics and the relationship. The critical total strain is calibrated using a thick wall test.

Abstract: A method of measuring a dry gas flow from hydrocarbon wells. The hydrocarbon wells produce a stream which contains liquids and natural gas. The method comprises providing an differential flow measurement device (orifice) located at a well site containing the hydrocarbon wells. The method further includes testing the stream for gas composition and physical characteristics. Additionally, the method comprises measuring a static temperature (T) of the stream, measuring a static pressure (Ps), and measuring a pressure differential (dP) in the differential flow measurement device (orifice). The method includes computing the liquid-gas ratio (LGR) of the stream, computing the wet gas flow rate (Qw) of the stream, computing a first dry gas flow rate (Qd1) and a second dry gas flow rate and utilizing a iterative process to correct and obtain the dry gas flow rate. The data may be transmitted to another location.

Abstract: A method for evaluating measured electromagnetic (EM) data relating to a subsurface region, comprising the steps of: (a) specifying alternative models of the region in terms of input parameters with uncertainty; (b) receiving the measured EM data and an estimated error; and (c) carrying out a Bayesian inversion on the measured data using each of the alternative models to attribute a probability to each model on the basis of the measured data and estimated error. The method allows physical measurements with error to be translated into fundamental parameters which can be used to assess business risk and uncertainty for making decisions, and also provides for parameters and models which can typically be directly estimated by a geoscientist on a coarse spatial grid to be used as an input, and validated using the measured data with error.

Abstract: A method for evaluating measured electromagnetic (EM) data relating to a subsurface region, comprising the steps of: (a) specifying at least one model of the region in terms of fundamental parameters with uncertainty, using a fundamental inversion grid; (b) receiving the measured EM data and an estimated error; (c) translating the fundamental parameters of the model to meta parameters of the region and to a computational grid suitable for forward modelling and comparison to the measured EM data, using relationships with uncertainty; and (d) carrying out a Bayesian inversion using the measured data and estimated error to produce an output comprising fundamental parameters of the region on the fundamental inversion grid with uncertainty.

Abstract: A method of method of determining relative contributions of two or more producing subterranean sources to a total flow is described using the steps of selecting a subset from a set of identifiable components in the total flow and using the subset to determine the relative contributions of two or more producing subterranean sources, wherein the subset is selected based on the sensitivity of the determination step to errors in the measurement of concentrations of said identifiable components.

Abstract: A method for constructing elastoplastic property correlations in multicomponent particulate systems. The method includes obtaining parameters from geophysical data of a sediment-hydrate system, where the parameters include shyd and pc, and where shyd is a hydrate saturation and pc is a confining pressure. The method further includes determining a Young's modulus (E) of the sediment-hydrate system using the parameters and a correlation, where the correlation is E p c = 90.58 + 78.90 ? 0.5831 + 800.4 ? s hyd 1.371 ? 1.022 , and where ?=pc/c and c is a scaling variable with dimensions of pressure. The method further includes adjusting a field operation based on the Young's modulus of the sediment-hydrate system.

Abstract: A drilling system provides indications of the lithology of the formation being drilled by dynamically measuring at least one parameter of interest that is affected by the lithology of the formation being drilled. Suitably positioned sensors make dynamic measurements of parameters such as downhole weight on bit, bit torque, bit revolutions, rate of penetration and bit axial acceleration. One or more processors use the sensor measurements in conjunction with predetermined lithological models to determine whether the measurements indicate a change in formation lithology. Suitable models can be on derived expressions such as rock drillability, drilling response, dynamic drilling response, normalized or dimensionless torque; and formation shear strength. The lithological indications provided by the processor can be used to adjust drilling parameters, steer the BHA, monitor BHA health, and provide depth locations for bed boundaries and formation interfaces.

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: Apparatus and method for downhole formation fluid sampling include conveying a carrier into a well borehole that traverses a subterranean formation of interest, the carrier having a port and placing the port in fluid communication with the subterranean formation of interest. The method includes urging a fluid into the port using a fluid control device, the fluid containing a formation fluid and a contaminant, generating a first signal indicative of a first fluid characteristic of the fluid using a first test device in communication with the fluid, and generating a second signal indicative of a second fluid characteristic of the fluid using a second test device in communication with the fluid.

Abstract: A method of automatically correlating well logs includes selecting well loops from the well logs and creating a set of possible marker positions for each well log in each well loop. From the possible marker positions, alternate marker sets are iteratively selected. A well tie error on each loop is calculated for each selected marker set, summed over all loops and minimized.

Abstract: A method is disclosed for generating an estimation of an incremental recovery that can be expected from an Enhanced Oil Recovery (EOR) Process, comprising: selecting a set of reservoir properties; selecting an EOR process that is associated with the selected set of reservoir properties; and generating the estimation of the incremental recovery that can be expected from the selected EOR process.

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: A method of determining the nature of a submarine or subterranean reservoir having an electromagnetic characteristic is described. The method comprises analyzing data associated with the application of a time varying electromagnetic field from above the reservoir using a data analysis methodology that does not utilize an estimate of the reservoir's geometry in determining one or more characteristics of the reservoir.

Abstract: A system, method and device may be used to monitor acoustic energy in a borehole. Electromagnetic energy is used to energize a resonant circuit incorporating a sensor. The sensor modulates the electromagnetic energy in accordance with received acoustic energy and transmits the modulated energy so that it may be received and processed in order to obtain the desired measurements.