Abstract: Disclosed is a diagnostic device for a seismic probe, the probe including, in an elongate tubular body, an electronic module, a capacitor bank and a spark gap adapted to generate a shock wave in a wellbore, the device including at least one sensor adapted to measure at least one parameter of the shock wave over time. The sensor is fixed to an inner surface of a wall of the tubular body, at a predetermined, non-zero distance from the spark gap in the direction of the electronic module. Also disclosed is a diagnostic method using the signals of the sensor.

Abstract: The present disclosure describes a system, method and computer readable medium capable of identifying and filtering erroneous seismic data from the computer modeling process. A visual representation of seismic data pertaining to a subterranean formation may be generated and displayed upon a graphic user interface utilizing one or more color schemes. A filtering arrangement may be applied to the seismic data and the visual representation may be updated to include one or more indications illustrating seismic data that has been selected for filtering. The user may adjust filtering operations utilizing a computer generated selection tool. In one embodiment, the system provides a suggestion tool capable of alerting the user to potential seismic data filtering problems.

Abstract: A method of modifying a seismic image of a subsurface region includes identifying a location within the seismic image that includes a distortion, indicating a structural change associated with the distortion, that is selected to at least partially correct for the distortion, identifying a region causing the distortion in which corrections to a velocity model corresponding to the seismic image are to be applied, performing an inversion for the region in accordance with the indicated structural change, updating the velocity model on the basis of the inversion, and producing a modified seismic image on the basis of the updated velocity model.

Abstract: A method can include accessing seismic data; providing a wave function that defines, at least in part, a correlation window length; generating local autocorrelation functions for the seismic data using the correlation window length; performing cross-correlations between the wave function and each of the local autocorrelation functions to provide local cross-correlation coefficient values; determining second derivatives of the local cross-correlation coefficient values to provide local second derivative values; and rendering the local second derivative values to a display. Various other apparatuses, systems, methods, etc., are also disclosed.

Abstract: An exemplary embodiment of the present invention provides a method for interpolating seismic data. The method includes collecting seismic data of two or more types over a field (401), determining an approximation to one of the types of the seismic data (402), and performing a wave-field transformation on the approximation to form a transformed approximation (405), wherein the transformed approximation corresponds to another of the collected types of seismic data. The method may also include setting the transformed approximation to match the measured seismic data of the corresponding types at matching locations (408), performing a wave-field transformation on the transformed approximation to form an output approximation (412), and using the output approximation to obtain a data representation of a geological layer (416).

Abstract: A discrete, minimally-equipped standard seismic calibration system is permanently installed over a subsurface reservoir structure that contains fluids of economic interest. Changes in the fluid content as a function of long-term time lapse may introduce changes in the acoustical characteristics of the reservoir rock layers, producing a corresponding change in the seismic signature recorded by the calibration system. The difference between two signatures over a selected time epoch defines a time-lapse calibration signature. The time lapse calibration signature can be applied to reduce the results of different conventional seismic data-acquisition systems of different vintages and technologies to a common standard.

Abstract: Apparatus and method are disclosed for use with a horizon picking method for 3D seismic data. Variables such as picking method, whether simple or iterative, score required of an iterative method and .DELTA.T between target wavelets and seed wavelet are input into the computer. During the picking process, parameters as to the number of successful picks and the number of failed picks because of the method of picking and because of failed picks due to the score not being achieved in the iterative method and because of failed picks due to the difference in time between the target wavelet and the seed wavelet being greater than the .DELTA.T variable are recorded. The number of score failures to pick a target wavelet from a seed wavelet is recorded where the score achieved is less than the input score. A characteristic of such number of score failures, such as the percentage of score failures to the total number of picking tries, is displayed on a CRT screen.

Abstract: A process for generating a surface slice for use in understanding or comprehending the internal structure of a multi-dimensional data volume and specifically a three-dimensional seismic data volume. The surface slice is a local N-1 dimensional representation of the internal structure of N dimensional data, where N represents the original dimension of the data volume. Information from the Nth-dimension is preserved in the N-1 dimensional surface slices. An arbitrary surface intersecting surfaces through the data volume is selected. A variant, an identifiable attribute of data which forms the surfaces of finite extent throughout the data volume, is also selected and isolated to identify the surface. Variants can include, but are not limited to, peaks, troughs, local peaks, local troughs, plus-to-minus zero crossings, and minus-to-plus zero crossings.

Abstract: A method for obtaining two way travel times for source and receiver pairs includes the steps of determining a set of one way travel times for each source to a plurality of image points and a set of one way travel times for each receiver to the plurality of image points. Ray sets are generated for both the sources and receivers. Travel times from a surface position to image points are computed by two point interpolation using the ray sets. Two way travel time is computed by summing two sets, one set each for the source and receiver positions. A two way travel time set is obtained for a particular source and receiver combination for all imaging points.

Abstract: A method and apparatus for immediate, substantially real-time representation of the traces of seismic measurements in which the exponents and sign of the signal sample from the stream of data transmitted to a data recording unit (2) are uncoupled and are displayed as gradations of color on a monitor (6) of a personal computer. in this manner a quick overview of the measurement can be obtained, and the correctness of the installation and the operability of the receivers can be determined.

Abstract: Apparatus for creating a video display from information generated by acoustically scanning a reflecting boundary circumferential of a borehole. A downhole tool generates a first signal each time a rotating transducer therein passes through magnetic north. Acoustic pulses emitted from the transducer are radially transmitted toward a borehole reflecting boundary. At least a portion of each pulse is reflected back to the transducer where the same is detected and converted to an electrical pulse representative of the reflected acoustic pulse. The peak of each electrical pulse is detected and the value digitized. A series of different addresses is associated with each digital value from a single 360.degree. borehole scan and the same are accumulated in a RAM with each digital value being stored therein at its associated address. A central processing unit selects a block of video memory locations in a video memory responsive to the magnetic north signal.

Abstract: Method and apparatus for storing, displaying and processing borehole televiewer signals, comprises digitizing means for the electrical scan signals (ESS), and for storing them in a register at slow input rates until a full 360.degree. scan is completed. A RAM provides storage for a full frame of T.V. raster scan signals, which are being withdrawn from the RAM, to the TV monitor, and back to the RAM. As complete rotary ESS are accumulated they are injected into the stream of circulating video signals to add a new line. Then a second line is accumulated at slow scan rate, read out at TV raster scan rate to add a second line to update the display, and so on. Means are provided for processing the data stored in the RAM in a variety of ways.

Abstract: Initialization data independent of logging curve data values (such as grid definitions and starting depths) are transmitted to a remote terminal where well log curve displays are desired. Data corresponding to magnitudes of successive adjacent points on the curves are then sequentially transmitted as delta values. Each delta value is the difference in magnitude between two adjacent sample points on a given curve. Transmission of redundant and unnecessary information such as integer values of curve samples is thereby eliminated. Large amounts of well log data may then be transferred quickly to remote locations at low data transmission rates associated with conventional telephonic communication links. Cumulative error resulting from reconstructing curve sample magnitudes from delta values is eliminated by a bi-directional transmission error checking scheme.

Abstract: In a system for displaying geophysical information on a video screen, data representative of spaced subsurface strata are stored in a computer memory. The data are extracted, plane by plane, and data bytes representative of the planes are stored in pairs in memories in an image processor. The data representative of one plane is displayed and recorded on a medium such as video tape. An image is then formed using a large fraction of the value of the data representative of one plane and a smaller fraction of the data representative of the next plane, and that image is stored. Successive images are formed using decreasing fractional amounts of the data representative of the first plane and increasing fractional amounts of the data in the next plane. Each image is stored and displayed, the display presenting a sequence of images which appear to merge or dissolve smoothly from one to the next. The process is repeated through all stored strata.

Abstract: Method and apparatus for concurrently and interactively displaying a selected plurality of measurable properties of geophysical data to empirically derive the best combined presentation of the selected attribute properties for interpretation. The technique of the present invention allows the interpreter to more easily comprehend simultaneous variation of several geophysical data attributes and to relate the effects to a specific end result for the geophysical indicators of interest. In accordance with the method, the one or more geophysical attribute variables are quantified and then rasterized so that the data is represented as a gridded variable area display wherein color intensity of the grid units is some function of the instantaneous variable. The resulting data is then loaded into digital refresh memory of an image processing computer whereupon it us interactively mixed for analysis in accordance with operator selected colors and color intensity weighting.

Abstract: A system and method for processing and displaying well-logging data provides direct indications of various lithological characteristics in conjunction with symbolic representatives of formation lithologies. Preselected programming of a two-dimensional symbol matrix into a memory device provides symbol flexibility. Geometric symbol matrices corresponding to different formation characteristics are digitally stored. When a preselected relationship occurs between lithological characteristics, the particular preselected matrix corresponding to the relationship is repetitively retrieved and displayed between the lithological characteristics curves. Because a relatively small digital matrix pattern may be used and repeated, only a small amount of storage is required for each symbol.

Abstract: Sample and hold circuits are utilized to divide data stored in memory into a plurality of channels for display. First-in-first-out buffers are utilized to compensate for the difference between the time required to read data from a memory and the time required for a sample and hold circuit to sample and hold the data.

Abstract: A display system is provided in which the data from a plurality of data channels is displayed on a cathode ray tube (CRT) display device. Automatic gain control is utilized to ensure that essentially the entire screen of the CRT display device is filled even if the number of data channels available to supply data to be displayed varies. Digital gain ranging circuitry is provided to ensure that the automatic gain control circuit is not overloaded by a large variation in the number of data channels available to supply data to be displayed. Circuitry is also provided to enable the highlighting of data from a particular data channel on the CRT display device to thereby provide easier viewing of the data, from that particular data channel, for an operator.

Abstract: The specification discloses a method and system wherein an operator interacts with an automatic data processing and display system to classify and sort subsurface reflective surfaces or segments in a multidimensional context. The technique utilizes a properly programmed general purpose digital computer in combination with a plurality of storage tube display screens. Seismic reflection data in the form of computer picked reflection segments, hereinafter referred to as seismic segment data, produced from previous computer processing steps is entered into the computer. Displays of the velocity, amplitude, dip and length of the segments in a space gate are then provided on the display screens. A data responsive surface having a network of conductive wires and a detecting stylus are utilized by the operator to operate upon the displayed segment data to classify primary segments and to define boundaries relative to each of the parameter displays.

Abstract: A novel seismogram display and method for making same are provided wherein a portion of the areas under certain ones of the positive and negative wavelet lobes of each seismic trace is shaded. Each shaded area originates at or near a null point. The novel seismogram allows an interpreter to correlate both partially shaded lobes per wavelet, instead of one completely shaded, single lobe per wavelet. The invention therefore greatly simplifies and enhances the correlation and interpretation process.

Abstract: Multiplexed seismic data representing a plurality of seismic channels intensity modulates each sweep of the electron beam of a cathode-ray tube. Each successive sweep of the electron beam is photographically reproduced on a rotating drum plotter to provide a seismic record section. The modulation of the cathode-ray tube is further controlled to provide for various seismic trace presentations on the record section, including wiggle traces, variable area traces, wiggle-variable area traces, and symmetrical-variable area traces.

Abstract: Multiplexed seismic data representing a plurality of seismic channels intensity modulates each sweep of the electron beam of a cathode-ray tube. Each successive sweep of the electron beam is photographically reproduced on a rotating drum plotter to provide a seismic record section. The sweep signal for controlling the electron beam is automatically gain controlled so that the number of seismic traces per inch remains constant.