Abstract: A method of identifying passive seismic events in seismic data that contains at least first seismic data traces acquired at a first seismic receiver and second seismic data traces acquired at a second receiver spatially separated from the first receiver comprises determining an overall measure of similarity for a pair of events in the seismic traces. The overall measure of similarity is indicative of similarity between the events acquired at the first seismic receiver and of similarity between the events acquired at the second seismic receiver. In one method, the overall measure of similarity is an overall cross-correlation coefficient. The overall cross-correlation coefficient is found by determining a first correlation coefficient for the pair of events from the data acquired at the first receiver and determining a second correlation coefficient for the pair of events from the data acquired at the second receiver.

Abstract: A system and method for microseismic fracture mapping using seismic source timing measurements for velocity calibration is disclosed. The system may include a seismic source coupled to a wireline and a seismic source trigger, a sensor capable of detecting a first signal from the seismic source trigger, a transmitter coupled to the sensor, capable of transmitting a time value associated with the first signal, a receiver capable of detecting an event generated by the seismic source; and an analyzer capable of calculating a microseismic velocity of the event. In one embodiment, a first signal is transmitted through a wireline to trigger a seismic source. The first signal is detected, and a first time value associated with the first signal is transmitted. An event associated with the seismic source is detected and a second signal associated with the event is transmitted to an analyzer.

Abstract: A method waveform processing technique utilizing signal coherence of the array data for processing signals having poor signal-to-noise ratio. Raw waveform data is first transformed into f-k (frequency-wavenumber) domain. A coherence function is then calculated and convolved with the data in the f-k domain, which effectively suppresses non-coherent signals in the data. For the remaining coherent data, the unwanted part is muted and the wanted part is retained and inverse-transformed to yield the coherence-filtered array waveform data. After this processing, small signals that are hidden in the original data are extracted with much enhanced coherence. Subsequent processing of the data yields reliable information about formation acoustic property.

Abstract: In some embodiments, an apparatus and a system, as well as a method and an article, may include generating attenuation values associated with a set of multiple signals received by multiple receivers from a transmitted signal as a function of reception time and material velocity. The attenuation values may be stored in a memory and/or displayed on a display, perhaps in conjunction with a semblance map.

Abstract: A data acquisition method of a non-real time transmitting seismic data acquisition system applied in mountainous areas. The format of original record file names is an 8 digit file name representing absolute time together with 3 digit extension names representing the equipment's serial number. The detonating units generate SPS format spreadsheets according to the above file name generation method. SPS format spreadsheets of several detonating units are combined on the basis of the SPS format spreadsheets generated by every detonating unit and then put in a data retrieval unit. The effective file names, which are recorded in the SPS format spreadsheets while detonating units are operating, are based on the former 8 digits. The acquisition unit and the data retrieval unit are connected by network lines, and a data retrieving program will run by the data retrieval unit. This method is exclusive and feasible to manage and search the seismic data.

Abstract: A deflector device (22) for use with a tow line between a seismic survey vessel and a tow, in particular a seismic streamer or streamer array, in the water behind the vessel comprises a vertically oriented wing-shaped body (28) shaped to produce in use a sideways force which urges the tow line laterally with respect to the direction of movement of the towing vessel. The wing-shaped body (28) includes one or more buoyancy elements, and a rearwardly extending boom (32). A pivotable control surface (54) extends sideways from the boom (32), and is shaped to produce in use a force having a substantial vertical component. The angle of the control surface is remotely controllable, in order to control the depth of the deflector device.

Abstract: A method, apparatus and system for acquiring land seismic data includes acquiring seismic data with a first autonomous seismic data acquisition unit and a second autonomous seismic data acquisition unit wherein each acquisition unit comprises a plurality of digitally controlled temperature-compensated crystal oscillators. Oscillator-based timing signals are acquired that are associated with the plurality of digitally controlled temperature-compensated crystal oscillators and a time correction is determined to apply to the seismic data acquired with the first autonomous seismic data acquisition unit. The time correction is determined using the oscillator-based timing signals from the first and second autonomous seismic data acquisition units.

Abstract: The invention relates to a method of determining impulse responses from a medium (2) in relation to the transmission of waves between different points (T1-TN). The inventive method consists in: transmitting waves in the medium by generating, at each point j, signals ei(t) each comprising n elementary signals with respective frequencies which are spaced apart in pairs by an interval ?f and which are different from the frequencies of the elementary signals corresponding to the other points; receiving signals rj(t) at points j after the transmission of the aforementioned waves in the medium; and calculating each impulse response hij(t) from a correlation signal between signal ei(t) transmitted at point i and signal rj(t) received at point j.

Abstract: An ultrasonic imaging method is provided. A wideband acoustic pulse is fired at a wall. A wideband response signal is received. The wideband response signal is processed to select an impedance measurement frequency. A wavelet having a characteristic frequency approximately equal to the impedance measurement frequency is fired. A wavelet response signal is received. A reflection coefficient is determined from the wavelet response signal. An impedance measurement is calculated from the reflection coefficient. Related tools and systems are also disclosed.

Abstract: Apparatus and methods for acquiring seismic data using a seabed seismic data cable positioned on a seabed are described, including correcting for the effect of one or more sensor non-linear motions, which improves accuracy of seismic data. One or multiple non-linear movements of the sensor may be corrected for. It is emphasized that this abstract is provided to comply with the rules requiring an abstract, which will allow a searcher or other reader to quickly ascertain the subject matter of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims. 37 CFR 1.

Abstract: Methods and apparatus facilitating radial profiling of formation mobility are disclosed. Radial profiling of formation mobility aids in an optimal completion of a well for enhanced production. Some aspects of the present invention provide a technique for radial profiling of formation mobility based on inverting differences between a Stoneley radial profile of horizontal shear slowness and a dipole radial profile of vertical shear slowness for a reservoir interval.

Abstract: An acoustic borehole logging system for generation and detection of multipole modes used to determine elastic properties of earth formations characterized as inhomogeneous anisotropic solids. The system concurrently generates and senses monopole, dipole, quadrupole and any higher order pole in the borehole/formation system in order to characterize the elastic properties and stress state of material penetrated by the borehole. Multipole modes of all orders are induced simultaneously without the need for separate transmitter and receiver systems. Performance of the logging system is not compromised due to eccentering of the axis of the tool in the borehole, tool tilt with respect to the axis of the borehole, or mismatch of response sensitivity of multiple receivers within the tool.

Abstract: A method and apparatus for use in seismic prospecting are disclosed. The method includes: attenuating coherent noise in a seismic data set generated from a sweep signal; and correlating the coherent noise-attenuated seismic data set to the sweep signal. The apparatus includes a program storage medium encoded with instructions that, when executed by a computing device perform the method and a computer programmed to perform the method.

Abstract: A system for remotely controlling, acquiring and monitoring the acquisition of seismic data. The system includes remote equipment for collecting seismic data and for transmitting and receiving communication signals to and from a remote location. The system also includes local equipment for transmitting and receiving communication signals to and from the remote location. In this manner, the collection of seismic data at remote locations can be controlled and monitored locally.

Abstract: The detailed analysis of cross well seismic data for a gas reservoir in Texas revealed two newly detected seismic wave effects, recorded approximately 2000 feet above the reservoir. A tube-wave (150) is initiated in a source well (110) by a source (111), travels in the source well (110), is coupled to a geological feature (140), propagates (151) through the geological feature (140), is coupled back to a tube-wave (152) at a receiver well (120), and is and received by receiver(s) (121) in either the same (110) or a different receiving well (120). The tube-wave has been shown to be extremely sensitive to changes in reservoir characteristics. Tube-waves appear to couple most effectively to reservoirs where the well casing is perforated, allowing direct fluid contact from the interior of a well case to the reservoir.

Abstract: The present invention provides for cable motion detection. In one aspect of the instant invention, a method is provided for cable motion detection using orientation sensor. The method includes determining at least one initial inclination of at least one orientation sensor coupled to a seismic cable, determining at least one current inclination of the at least one orientation sensor, and determining whether the at least one seismic cable has moved from the at least one initial inclination and the at least one current inclination.

Abstract: The invention relates to a method for fracture plane reconstruction in a three-dimensional set (20) of values, comprising the steps of providing a computer with the three-dimensional set, display by the computer of a succession of plane sections (10) of the three-dimensional set, selection by the user of points of the fracture plane over some of these sections during their display; and reconstruction by the computer of the fracture plane from the selected points.

Abstract: The apparatus has a sensor disposed on the first end of an elongate connector by means of fixed interface link. A recorder unit is disposed on the second end of the connector opposite the first end. The connector is bendable within a predefined curvature range. When the apparatus is deployed into the sea, it is adapted to free-fall through the body of water and to land on the seafloor such that the sensor is spaced apart from the recorder unit. The apparatus is additionally adapted to substantially vibrationally de-couple the sensor from the recorder unit. The length of the connector is dynamically variable within a predefined range so as to minimize vibration coupling between the recorder unit to the sensor. Physical separation of the sensor and the recorder unit, together with the mechanical characteristics of the connector, ensure that the sensor is substantially vibrationally de-coupled from the recorder unit.

Abstract: A network distributed seismic data acquisition system comprises seismic receivers connected to remote acquisition modules, receiver lines, line tap units, base lines, a central recording system and a seismic source event generation unit synchronized to a master clock. One or more high precision clocks is added to the network to correct for timing uncertainty associated with propagation of commands through the network. Seismic receivers and seismic sources are thereby synchronized with greater accuracy than otherwise possible. Timing errors that interfere with the processing of the seismic recordings are greatly reduced, thus enabling an improvement in subsurface geologic imaging.

Abstract: A method of increasing the collapse resistance of a tubular comprises locating a tool having at least one, and typically three, bearing members within a tubular. The bearing members are positioned in engagement with a wall of the tubular to apply a radial force to a discrete zone of the wall. This radial force is then applied to further discrete zones of the wall, the level of radial force being selected such that the collapse resistance of the tubular is increased.