Abstract: An electromagnetic tomography system for determining properties of geological formation penetrated by at least one borehole lined with a conductive tubular includes a transmitter disposed in a first borehole and adapted to induce a magnetic field, a first receiver disposed in the first borehole and adapted to detect a magnetic field induced in the conductive tubular by the transmitter, and a second receiver adapted to detect a magnetic field induced in the geological formation by the transmitter.

Abstract: An apparatus and method for combining a survey measurement dataset and a position dataset into a single dataset containing both measurement and position data is disclosed. The survey measurement data may be obtained from a ground penetrating radar, an inductometer, a magnetometer, or an optical camera. Positioning information is collected and merged with the survey information so that the position of the survey tool is known at each data point. Also provided are channel-equalization filters, spiking deconvolution filters, and frame filters that can be used in conjunction with the positioning information to enhance the quality of the images obtained from the data collected by the survey tool.

Abstract: The specification discloses a signal processing technique applicable in acoustic logging devices. The method involves receiving a set of acoustic signals and converting those received signals to their frequency domain representation. Values of the frequency domain representations along constant frequencies are correlated to produce a correlation matrix. Eigenvectors and eigenvalues of the correlation matrix are determined, and the eigenvectors corresponding to signals of interest are removed to create a subspace. Thereafter, a series of test vectors, which test vectors embody a series of estimated slowness values, are applied to the subspace vector. If the test vector maps to or may be represented by the subspace, then the estimated slowness embodied in the test vector maps to noise of the system and is not the correct value for the formation. If, however, the test vector does not map to the subspace, then the slowness embodied in the test vector approximates the actual formation slowness.

Abstract: A method for detecting and visualizing changes in a borehole, comprising correlating a time-depth file and a time-data file to obtain a plurality of measurements at a specific depth for a parameter, analyzing a parameter change using at least two of the plurality of the measurements to obtain an interpretation of the parameter change, and displaying the interpretation of the parameter change using a graphical representation.

Abstract: In a Digital Pressure Derivative Technique (DPDT) which uses convolution, an input signal including noise is convolved with a wavelet to produce an output signal which is a derivative of the input signal and which is substantially devoid of the noise. The DPDT can be used in many applications; however, in one such application, a pressure signal from a wellbore including noise is convolved with a special wavelet to produce an output signal which is the derivative of the input pressure signal, the output signal being substantially devoid of the noise. The wavelet is made from the unit sample response of a bandlimited, optimum linear phase Finite Impulse Response digital differentiator. The DPDT technique enables analysts to customize the differentiation based on the quality of the measured data without having to use traditional, subjective smoothing algorithms.

Abstract: A graphical user interface of a well logging display program for editing data records included in well logging data includes multiple windows and controls for user interaction. The well logging data includes measurements of logging variables collected at successive depths to define the data records. The multiple windows include a first window for displaying depth versus time measurements, a second window for defining a logging variable, a third window for selecting and displaying a first set of instances of the logging variable, and a fourth window for selecting and displaying a second set of instances of the logging variable. The multiple controls include a bar line for selecting a splice point, and an interface button for instructing the program to edit the data records. The edited data records include measurements corresponding to the first and second set of instances being spliced in accordance with a predefined function.

Abstract: The present invention finds the acoustic impedance of the drilling fluid using reflections from a precise metal disk, and therefrom the density of the drilling fluid. Because the reverberation characteristics of an acoustic wave depend in part on the acoustic wave shape, the first reflection from the metal disk may be used to calibrate the measurement. A method for determining a borehole fluid property is disclosed that includes (i) generating an acoustic signal within a borehole fluid, (ii) receiving reflections of the acoustic signal from the fluid, and (iii) analyzing a reverberation portion of the acoustic signal to determine the property. The analyzing of the reverberation portion may include obtaining a theoretical reverberation signal and relating the measured reverberation signal with the theoretical reverberation signal to determine the borehole fluid property.

Abstract: The present invention provides a graphical method to design and modify the trajectory of a well bore. A well bore trajectory plan is comprised of hold and curve sections. Hold sections are generally described by specifying the attitude of the hold and the length of the hold. Curve sections can be described and represented in a variety of ways. The present invention introduces control points that are formed at the intersection of extensions/projections of the two hold sections contacting a curve section. The hold sections contact the curve section at tangent points. The tangent points for a curve section have the same distance to the control point. In operation, as a control point is moved, the direction and inclination of multiple sections of the well plan are simultaneously modified. These simultaneous modifications enable the user to quickly and intuitively modify a well plan.

Abstract: A method of processing multi-component seismic measurement-while-drilling data that includes rotating the data to align energy in the data along a common axis and then combining the data. Another embodiment of the inventive method involves a technique for estimating the orientations and/or change in orientation of a bottom hole assembly associated with two or more series of multi-component seismic MWD data acquired at different times at the same source and receiver locations. Embodiments of the inventive method may be used to improve the signal to noise ratio of the data, to reduce downhole storage and transmission requirements, and to improve direct arrival time picks made using the data.

Abstract: A method, apparatus and system for detecting seismic waves. A sensing apparatus is deployed within a bore hole and may include a source magnet for inducing a magnetic field within a casing of the borehole. An electrical coil is disposed within the magnetic field to sense a change in the magnetic field due to a displacement of the casing. The electrical coil is configured to remain substantially stationary relative to the well bore and its casing along a specified axis such that displacement of the casing induces a change within the magnetic field which may then be sensed by the electrical coil. Additional electrical coils may be similarly utilized to detect changes in the same or other associated magnetic fields along other specified axes. The additional sensor coils may be oriented substantially orthogonally relative to one another so as to detect seismic waves along multiple orthogonal axes in three dimensional space.

Abstract: Techniques are presented for determining the drift of a clock adapted for subsurface disposal. Seismic signals are transmitted through the subsurface medium from an uphole location at selected times, acoustic signals associated with the transmitted seismic signals are received with acoustic sensors at identified downhole locations. First and second transit times for acoustic signals received at an identified downhole reference location are determined using the clock. A time difference between the first and second signal transit times at the reference point is calculated to determine the clock drift.

Abstract: A technique usable with a subterranean well includes deploying a first optical sensor downhole in the subterranean well. The technique includes observing an intensity of backscattered light from the first optical sensor to measure a distribution of a characteristic along a portion of the well. The technique includes deploying a second sensor downhole to measure the characteristic at discreet points within the portion. The second sensor is separate from this first sensor and includes at least one interferometric sensor.

Abstract: The present invention is a system and method for searching a large database of dig location tickets for tickets of particular interest. A user can locate an area of concern on an on-screen map and can view a list of tickets received for a given date range of the map. For example, when underground plant damage occurs in a particular region, users need not text-search in the database to locate a particular ticket that may have caused the damage, but can instead locate the ticket using the enhanced on-screen map of the invention.

Abstract: A method of determination of fluid pressures in a subsurface region of the earth uses seismic velocities and calibrations relating the seismic velocities to the effective stress on the subsurface sediments. The seismic velocities may be keyed to defined seismic horizons and may be obtained from many methods, including velocity spectra, post-stack inversion, pre-stack inversion, VSP or tomography. Overburden stresses may be obtained from density logs, relations between density and velocity, or from inversion of potential fields data. The seismic data may be P-P, P-S, or S-S data. The calibrations may be predetermined or may be derived from well information including well logs and well pressure measurements. The calibrations may also include the effect of unloading. The determined pressures may be used in the analysis of fluid flow in reservoirs, basin and prospect modeling and in fault integrity analysis.

Abstract: A system and method for viewing well log data. An identifier associated with a wellbore is entered into a display device at a first location. The well identifier is transmitted to a first database at a second location having well log data or ancillary data therein. The well log data or ancillary data are sent to the first location, and a table of contents indexing the data is generated for display on the display device. The table having selection fields linked to multiple data dimensions so that random selection by a user displays the selected data on the display device.

Abstract: A method for determining the composition of a fluid by using measured properties of the fluid. One embodiment of the method of the current invention generally comprises: selecting a fluid property that has a response to fluid composition that is linear, or can be approximated as linear; measuring the selected fluid property at a series of specific time intervals; and plotting the measured property as a function of the selected property. In effect, plotting the measured property as a function of fluid composition in an arbitrary set of units. This allows for a in-situ qualitative evaluation of fluid composition by measuring a fluid property that has a known linear relationship to fluid composition. Another embodiment of the present invention further comprises, establishing the endpoints of contamination and plotting the measured properties through these endpoints. Once the endpoints have been established a quantitative evaluation of the fluid composition can be performed.

Abstract: The invention is a method of determining horizontal and vertical resistivity in an anisotropic formation using a combination of orientable triaxial and array antennae conveyed downhole. Measurements are taken at various azimuthal angles about a measuring device at a given depth. Values at each azimuthal orientation can be fit to a curve to yield information on the surrounding formation. Multiple measurements at a given depth and azimuthal orientation can be weighted to obtain an average value. Values from the curve fitting process are used in subsequent inversion processing and reduce the uncertainty of the inversion processing result. Utilization of a three dimensional geometry enables a unique resolution of the orientation of the principle axis of anisotropy, and consequently of horizontal and vertical resistivity, and dip.

Abstract: Disclosed is a method for chemical analysis of drilling-, drill-in, completion-, formation-, and production fluids, which may be employed at rig site or in a remote location, comprising:

Abstract: A system for measuring density of material which can be embodied to measuring bulk density of material penetrated by a borehole. The probe component of the system comprises a source of neutron radiation and preferably two gamma ray spectrometers. The neutron source induces gamma radiation with energies up to about 10 MeV within the material being measured. Formation bulk density is determined by combining spectra of the induced gamma radiation with preferably two gamma ray spectrometers at differing axial spacings from the source. The high energy and dispersed nature of the induced gamma radiation yields greater radial depth of investigation than that obtainable with prior art backscatter density systems, which typically use gamma ray sources local to a probe and of energy about 1.3 MeV or less. The system can alternately be embodied to measure other material properties and to measure density of materials not penetrated by a borehole.

Abstract: The present invention provides a drilling system that utilizes a neural network for predictive control of drilling operations. A downhole processor controls the operation of the various devices in a bottom hole assembly to effect changes to drilling parameters and drilling direction to autonomously optimize the drilling effectiveness. The neural network iteratively updates a prediction model of the drilling operations and provides recommendations for drilling corrections to a drilling operator.

Abstract: A method and system for controlling and monitoring the quality of concrete based on the concrete's maturity (which is a function of its time-temperature profile, or temperature history). Five different applications or embodiments of the present invention are discussed, namely, Enhanced Maturity, Moisture-Loss Maturity, Improved Maturity, SPC Maturity, Loggers, Readers, and Software. Enhanced Maturity involves a maturity calibration method to account for the water-to-cementitious-materials ratio, air content, and gross unit weight of the concrete. Moisture-Loss Maturity is a method for determining the appropriate time to terminate moisture-loss protection of concrete and concrete structures. Improved Maturity is a method and system for determining the strength of curing concrete using improved maturity calculations.

Abstract: A method is provided for selecting a cementing composition for sealing a subterranean zone penetrated by a well bore. The method involves comprising determining a group of effective cementing compositions from a group of cementing compositions given estimated conditions experienced during the life of the well, and estimating the risk parameters for each of the group of effective cementing compositions.

Abstract: Borehole orientation information, typically azimuth and inclination, is derived from measurements of gravitational and magnetic components along a borehole axis (O) and transverse thereto. The transverse components are measured by a fluxgate (12) and accelerometer (14) arranged to rotate around the borehole axis (O) at a constant angular velocity (w). The calculations necessary to derive the desired parameters are detailed.

Abstract: Systems and methods for locating and identifying structures beneath a surface of the earth by processing and transforming a signal transmitted from a horizontal borehole at a specific depth from a surface of the earth into a representation of underground structures.

Abstract: A method is disclosed for producing a single logging-while-drilling (LWD) merged caliper from several indirect LWD borehole size measurements. The merging accounts for the varying validity of each input borehole size measurement as a function of the environment, the formation, and the borehole size itself. In one embodiment, the method includes obtaining a plurality of borehole size measurements from a plurality of LWD sensors and weighting each measurement with varying measurement confidence factors. One embodiment of the method includes determining a set of mathematical equations representative of the responses of the multiple sensors and solving the equation set to determine the borehole size. A computer encoded with instructions for weighting borehole size inputs and iteratively processing the weighted inputs to determine the merged caliper is also disclosed.

Abstract: A method for tomographic modeling of seismic wave travel times from well drilling records generated by drill string vibrations during drilling and identifying in the recorded vibration at least one of direct, reflected, refracted, converted and diving waves so as to measure wave velocity in near surface layers.

Abstract: A method for surveying a borehole is disclosed which uses first and second gravity measurement devices disposed at corresponding first and second positions in the borehole and a supplemental reference measurement device disposed at the first position. Exemplary supplemental reference measurement devices include magnetometers and gyroscopes. The method includes determining a reference borehole azimuth at the first position using the supplemental reference measurement device, determining a change in borehole azimuth between the first and second positions using the first and second gravity measurement devices and determining the borehole azimuth at the second position by applying the change in borehole azimuth the reference azimuth. A system adapted to execute the disclosed method and a computer system including computer-readable logic configured to instruct a processor to execute the disclosed method are also provided.

Abstract: The present invention generally provides methods of geological analysis. The method includes collecting wellbore data from a well undergoing underbalanced drilling. The wellbore data is then correlated to a seismic data to predict geological properties away from the wellbore. In one embodiment, correlating the seismic data with the wellbore data involves converting the seismic data and the wellbore data to a one-dimensional numerical series, respectively. The two respective one-dimensional numerical series are compared to each other to produce a mathematical formulation relating the two series. In another embodiment, the wellbore data may be separated into different categories or classifications and individually compared to the seismic data. Preferably, the categories are compared to two or more variations of seismic data and their attributes to derive at unique “signatures” for the respective category.

Abstract: Apparatus for determining the path of a well bore during drilling, comprises an inertial measurement unit (12) for providing data from which position, velocity and attitude can be derived, the measurement unit comprising a plurality of inertial sensors mounted on a platform assembly which is, in use, disposed within a drill string (6), and a drive unit (5) for rotating the platform assembly so as to control the rate of angular displacement of the platform assembly with respect to an Earth fixed reference frame.

Abstract: A method for quantifying permeability of a vuggy reservoir includes determining a permeability modeled with matrix porosity (K0) of the reservoir, determining a vug porosity (&PHgr;vug) of the reservoir, and quantifying permeability (K) of the reservoir as follows: K=aK0·bc&PHgr;wg, where a, b, and c are constants.

Abstract: A system and method managing safety data in a Web-based application that may preferably be used by offshore oil and natural gas production platform operators to verify and store Safety and Environmental Management Program for Outer Continental Shelf Operations and Facilities compliance data. The system provides a reporting system for the orderly accumulation of safety system test data that can then be used for operational analyses, reliability studies, and reports that may be required by regulatory agencies. In a preferred embodiment, the system uses security technology to ensure the security and confidentiality of the client data. Users may access the application via their existing Internet browser to access the system Web site. After entering data, which may preferably be verified by the system, the user is provided with a report regarding compliance.

Abstract: The present invention is a method of estimating formation properties by analyzing acoustic waves that are emitted from and received by a bottom hole assembly.

Abstract: The present invention is a method of estimating formation properties by analyzing acoustic waves that are emitted from and received by a bottom hole assembly.

Abstract: The total porosity of said formation, a fractional volume of the shale, and a resistivity of the shale are determined in a laminated reservoir including sands that may have dispersed shales therein. A tensor petrophysical model determines the laminar shale volume and laminar sand conductivity from vertical and horizontal conductivities derived from multi-component induction log data. The volume of dispersed shale and the total and effective porosities of the laminar sand fraction are determined using a Thomas-Stieber-Juhasz approach. Removal of laminar shale conductivity and porosity effects reduces the laminated shaly sand problem to a single dispersed shaly sand model to which the Waxman-Smits equation can be applied.

Abstract: Method for determining at least one optimal trajectory between a point and a target situated in a medium and forming a centered volume, the position of each of whose points is known with geometrical uncertainties, characterized in that it consists in defining for the centered volume a gain which takes different values from the center to the peripheral boundary, and a zero value outside the centered volume; in determining a statistically significant number of instances of the positions of the centered volume as a function of the geometrical uncertainties which affect it, and in determining an aggregate gain at each point; in defining a volume of interest, site of the points with positive aggregate gains in the medium; in defining curvilinear trajectories between at least one entry point and at least one exit point of the said volume of interest; in integrating the aggregate gain along each of the said curvilinear trajectories in such a way as to obtain a profit associated with each trajectory, and in retaining

Abstract: A method and apparatus is provided to support a gyroscope within a downhole drilling tool. A packaging system is positioned within a drill collar of the drilling tool and includes a housing for the gyro and at least one centralizer supporting the housing within the drill collar. The system may also be provided with a down-hole end cap, an up-hole endcap and a loading device. A gyro compression mechanism that is capable of holding wires may also be included to provide power and communication while compressing the gyro to isolate it from shock or vibration.

Abstract: A wireline well-logging data acquisition system and method with corrected depth index. The system having a winch for reeling-in a wireline cable connected to a well-logging tool. A depth index device and a cable tension meter are connected to the wireline cable. A computer system adjusts the depth index as a function of wireline tension measured by the cable tension meter. The computer system executes a method that includes a control loop for adjusting the depth index as function of the wireline tension.

Abstract: In a method for a well logging data presentation, data sets are identified from well logging data. Each data set is assigned a unique identifier. A presentation template, which defines a presentation for the well logging data, is configured. The presentation for the logging data may be in the form of a display and/or a hard copy. The presentation template includes definitions of a number of component presentations. Each component presentation includes a corresponding component template. Each component template includes a pointer pointing to a source for one of the data sets and defines a structure for the component's presentation. A graphical presentation program generates the presentation, responsive to reading the presentation template, component templates and data sets. The presentation can be viewed and changed while data is still being acquired.

Abstract: A method is provided for selecting a cementing composition for sealing a subterranean zone penetrated by a well bore. The method involves comprising determining a group of effective cementing compositions from a group of cementing compositions given estimated conditions experienced during the life of the well, and estimating the risk parameters for each of the group of effective cementing compositions.

Abstract: A method of estimating a petrophysical property of a subsurface area that includes deriving an acoustic calibration relationship correlating acoustic propagation characteristics of a first subsurface area with a petrophysical property of the first subsurface area determined using nuclear spectroscopy measurements; processing acoustic data acquired from a second subsurface area to determine acoustic propagation characteristics associated with a plurality of regions within the second subsurface area; and estimating the petrophysical property of the regions within the second subsurface area using the calibration relationship and the acoustic propagation characteristics associated with the second subsurface area.

Abstract: The present invention relates to a method for facilitating monitoring, in the course of time, of the evolution of an underground zone by compared analysis of a certain number n of seismic record sets obtained respectively after n successive 3D seismic surveys (method referred to as 4D seismic method). The method comprises using a pattern recognition technique applied to all of the seismic events of the n surveys considered and analyzed simultaneously, which allows showing the evolution of the seismic events in the subsoil. The invention has an application for monitoring of changes occurring in a reservoir zone of the subsoil during production for example.

Abstract: An oilfield equipment identifying apparatus comprising a computer loaded with an oilfield equipment database. A unique identification code is input into the computer for each piece of oilfield equipment in the drill string to form a reference in the oilfield equipment database to each piece of oilfield equipment in the drill string. A drilling monitoring device receives input signals indicative of at least one of rotating and non-rotating usage of the drill string and output signals to the computer wherein the computer continuously and automatically monitors the cumulative rotating usage and non-rotating usage of each piece of oilfield equipment identified in the drill string.

Abstract: A reservoir in payrock in analysed using finite element simulation. A reservoir engineer selects an appropriate model from a set of template models, each including a set of polygons in plan and layers in elevation. The polygons are defined in objects instantiated from classes by control points and the layers as depth values of control points. A pattern object sweeps rotationally about a wellbore in a wellbore polygon to define a pattern of elements, fewer in number with distance from the wellbore. A polygon object also sweeps linearly from a generator line in the direction of a base line. The generator and base lines correspond to polygon boundaries. Finite element simulation is performed with the model so derived.

Abstract: A method for determining a formation profile surrounding a well is used to establish a first formation profile using a neural network inversion method. A synthetic log is generated from the first formation profile and if the synthetic log converges with a real log, the formation profile parameters associated with the synthetic log are output. Otherwise, the first formation profile is modified and a new synthetic log is generated.

Abstract: A product-sum operation portion for performing a product-sum operation (wavelet transformation) with respect to an input time-series signal by using as a base of integral a complex function in which the imaginary number portion is &pgr;/2 shifted in phase from the real number portion, a phase calculation portion for calculating a phase &thgr; from the ratio between the real number portion and the imaginary number portion of a result of the product-sum operation, a peak time detection portion for detecting a time point at which the calculated phase &thgr; changes from 2&pgr; to zero, as a peak time, are provided. Since the wavelet transformation is performed by using a basic wavelet function that is localized in terms of time and frequency, a peak time can be promptly detected. Furthermore, since a differential operation is not employed but the product-sum operation is performed, false detection caused by noises or the like can be prevented.

Abstract: A method and system are disclosed for NMR echo-train data acquisition and processing for enhanced tracking of the error in the signal due to magnetoacoustic effects, known as ringing, that are not cancelled out or otherwise corrected. In one aspect, the method enables correction of ringing signals in a single pass by way of collecting a composite signal that includes echoes due to pulses at least at two different frequencies. The choice of one or more of the frequencies, the phase of the pulses, and the recovery period enable cancellation of the ringing signal from the echoes, including the echo from an excitation pulse. In another aspect, the method encompasses providing protection against errors due to tool motion by saturating a relatively wide sensitive region with the echo signals collected from within this relatively wide sensitive signal. Preferred embodiments of the invention include one or more of the aforementioned aspects.

Abstract: A method for identifying environmental effects in well log data includes selecting a plurality of models, each of the plurality of models including at least one parameter to be optimized; fitting the models to the well log data by optimizing the at least one parameter, the fitting producing a plurality of optimized models; determining an indicator of goodness of fit for each of the plurality of optimized models; and selecting a model representing a best fit of the well log data based on the indicator.

Abstract: Methods and tools are provided for real time velocity imaging of a borehole wall with sufficiently high resolution to identify vugs, worm holes, thin beds, dip angles, fractures and breakouts, for both open hole logging and logging while drilling in the presence of OBM's. A method is provided which includes transmitting an ultrasonic pulse through the borehole wall, receiving at first and second spaced-apart receivers an ultrasonic pulse refracted from the borehole wall, and producing a velocity image data value indicative of difference of arrival times at first and second spaced-apart receivers. This is repeated at a plurality of azimuths and depths to produce a velocity image data set. The method uses compressional pulses and/or pseudo-Raleigh pulses. A tool is provided for wireline use having an ultrasonic transmitter for transmitting ultrasonic pulses into the borehole wall, and a plurality of ultrasonic receivers.

Abstract: An apparatus and system are disclosed for in situ measurement of downhole fluid flow using Doppler techniques. First, a baseline speed of sound is established as close to the desired measurement point as possible. This speed of sound measurement is then used in Doppler calculations for determining flow velocities based from induced Doppler shift resulting from fluid flow. A heterodyne receiver arrangement is preferably used for processing so that the flow direction can be determined and the detection sensitivity for low flow velocities can be enhanced. From in situ measurements, well kicks may be spotted and dealt with in real-time. In addition, current theoretical models of Theological properties may be verified and expounded upon using in situ downhole measurement techniques. Furthermore, the velocity measurements described herein can be used to recognize downhole lost circulation and/or gas/water/oil influxes as early as possible, even when the mud recirculation pumps are turned off.

Abstract: A method for supplying a customer with well log data including obtaining wellsite properties from the customer, recommending at least one tool string and analysis software tool combination using the wellsite properties, processing well log data using customer domain information and the least one tool string and analysis software tool combination to obtain processed well log data, viewing the processed well log data using an interactive viewer, manipulating the customer domain information, and updating the processed well log data on the interactive viewer using the manipulated customer domain information.