Abstract: The instant invention is generally directed toward methods of using an AVO-type analysis on unstacked seismic data to identify subsurface exploration prospects. More particularly, a new method of identiflying and displaying converted mode seismic reflections is provided that has significant advantages over that in the prior art. Additionally, the instant invention can be used to attenuate or eliminate seismic reflections such as multiples that are not flattened by conventional velocity analysis. Further, a method is disclosed that provides for identification and display of only those seismic reflections deemed consistent with the usual or expected AVO behavior. Finally, another aspect of the instant invention involves the use of statistical goodness of fit measures, such as the Coefficient of Determination, to create a seismic display that is indicative of the degree to which each time slice in a gather conforms to a proposed AVO model.

Abstract: A seismic sensor array includes a means for passive electrical to optical energy transformation and transmission. This transformation is used remotely with traditional sensor arrays, which may include hydrophones, geophones, or a combination of them. The transformation means is used to develop an optical signal in a fiber which then conveys the seismic signals to a recording center or data accumulator.

Abstract: A method for measuring depths of a waterway, including the steps of determining nautical chart vertical reference values along a selected waterway, building a data base of the reference values and storing the data base in a computer accessible from the vessel, providing a radio receiver onboard the vessel and Global Positioning System (GPS) equipment accessible from the vessel, and operating the computer, radio receiver, and GPS equipment to continuously obtain positions of the vessel horizontally, and computations as to depth of the vessel above a pertinent vertical reference value.

Abstract: Adaptive neural networks can be used to effectively enhance signal detection in the inherently noisy environment of an oil well. The neural network can be either non-recurrent or recurrent in nature. The system is implemented with a computer that accepts input from at least one sensor mounted to the wellhead or near the wellhead. The detected contaminated signal is a combination of the event signal and the noise from the environment. The event signal can be, for example, the detonation of a perforation gun. The noise can be either random or periodic. The use of adaptive filtering allows the noise to be more precisely predicted and then subtracted from the contaminated signal to produce a cleaner representation of the event signal. Once the predicted noise is subtracted, the remaining event signal can be analyzed using voice or sound recognition systems to produce an output describing what event occurred.

Abstract: A system for distributing weather information accepts differing types of such information for storage in a number of databases. Data representing levels of precipitation are stored in an overall database, to be overwritten as new data becomes available. Data representing storm warnings and lightening strikes are stored in a time-sensitive database, to be erased according to a predetermined schedule. Data representing a satellite photograph of cloud cover are stored in a cloud map database. These databases are read to obtain data which is transmitted to terminals within various regions, so that each terminal receives weather information for an area surrounding its region.

Abstract: An integrated physical and statistical method provides predictions of a reservoir property by operating on seismic data both before and after it is significantly enhanced, e.g., stacked/filtered. One or more matrix functions are derived from pre-stacked, partially-stacked, and/or post-stacked seismic data that are used to obtain a new attribute as well as to correlate/integrate the physical and statistical methods to obtain significantly improved predictions of a reservoir property.

Abstract: A Linear Solver method and apparatus, embodied in a Simulator and adapted for solving systems of non-linear partial differential equations and systems of linear equations representing physical characteristics of an oil and/or gas reservoir, includes receiving a first signal representing physical characteristics of a reservoir, obtaining a residual vector {right arrow over (r)}0 from the first signal (representing errors associated with a system of nonlinear equations describing the reservoir) and a first matrix A0(representing the sensitivity of the residual vector to changes in a system of nonlinear equations), recursively decomposing matrix A0 into a lower block triangular matrix, an upper block triangular matrix, and a diagonal matrix, and generating a second matrix M0 that is an approximation to matrix A0.

Abstract: An apparatus and system for integrating acoustic pods within marine seismic streamers. The integrated acoustic pod eliminates the attachment and detachment of acoustic pods from the streamer exterior surface when the seismic streamers are deployed into and retrieved from the water. Control electronics are integrated within the streamer interior and receive electric power from a streamer electrical conductors and receive control signals from a streamer control wire. The control electronic components can be integrated within the streamer interior or within modules connecting each streamer section. Acoustic transducer elements can extend through the connector module or can be attached to the connector module exterior. The acoustic transducer elements can be oriented to steer transmission of acoustic energy into the water, such as in a horizontal azimuth, and to permit correction of the steering direction.

Abstract: An expandible diverter for use in marine seismic operations. The diverter is stored in a retracted position for transport and handling, and is expandible to increase the amount of surface area in contact with the water. The diverter can be formed with two or more moving components, and can comprise an expandible body. A controller can increase or decrease the amount of surface area in contact with the water to meet different conditions, and can control movement of the diverter as seismic vessel tows the diverter through the water.

Abstract: A method of sparse hyperbolic inversion is used to suppress multiples in marine seismic data. By explicitly including the two-way water-bottom reflection traveltime and water-bottom reflection coefficient as part of an augmented model domain, the inversion may be successfully carried out even for intermediate water depths and sloping water bottoms. Linear noises can also be suppressed by appropriate definition of the model. The invention also has the capability of handling time-varying wavelets or several different wavelets simultaneously. This latter capability is useful in suppressing dispersive ground roll on land seismic data.

Abstract: A method of focusing the measurements from an array type induction logging tool using an inhomogeneous background rather than a homogeneous background. A modeled inhomogeneous background response can be separated from the measured response and focused directly using focusing target functions. The residue, the difference between the measured response and the background response, can then be focused using conventional linear focusing methods. A final focusing response is obtained by adding the two focusing responses.

Abstract: A sonic or acoustic tool having a transmitter and a receiver and further having a receiver testing and calibration device is disclosed. Methods for testing and tuning acoustic receivers dynamically are also disclosed. The calibration device includes an acoustic signal generator in acoustic communication with a receiver or a plurality of receivers, where the generator generates an acoustic calibration signal or test signal which propagates to each receiver. The receiver response is monitored to determine receiver integrity and tune. Based on the response, the processing unit or units can adjust the receiver response or instruct tuning circuitry associated with the receiver to adjust the receiver response.

Abstract: A method for automatic modelling of the stratigraphic structure of an underground zone with fast adjustment of the parameters of the model with observed or measured data is disclosed.

Abstract: The processing of surface seismic data may be monitored where vertical seismic profile data are available for the same region. A trace (45) of the vertical seismic profile data recorded from a geophone at the surface is compared with data generated by the data processing before completion of migration and provides a measure of the quality of the data processing. Alternatively, a derived trace may be derived by taking sections of the vertical seismic profile data traces along a section curve (47). The derived trace may be thought of as partially migrated data and may similarly be used for monitoring the quality of surface seismic data processing.

Abstract: A computer system (30) and method of operating the same to analyze well log data so as to distinguish fractures from drilling artifacts, such as caves, washouts, and breakouts, is disclosed. According to the disclosed system and method, a Stoneley wave well log obtained at a plurality of depths is analyzed at a low and a high frequency, to generate a low frequency reflection coefficient trace over depth and a high frequency reflection coefficient trace over depth. Comparison of these reflection coefficient traces with one another will indicate whether a reflecting feature includes a fracture (as indicated by good low frequency response) or a cave, washout, or other artifact (as indicated by good high frequency response), or both. The particular methods disclosed include the generation of the reflection coefficient traces through back-projection stacking of deconvolved impulse traces at both frequencies, and applying and evaluating an envelope function to the stacked traces.

Abstract: A seismic sensor array includes a means for passive electrical to optical energy transformation and transmission. This transformation is used remotely with traditional sensor arrays, which may include hydrophones, geophones, or a combination of them. The transformation means is used to develop an optical signal in a fiber which then conveys the seismic signals to a recording center or data accumulator. The transformation means preferably comprises a stack of piezoelectric elements capped on each end by a rounded crown to accommodate an optical fiber wound around the stack and the crowns.

Abstract: A method and system for determining the azimuth position and distance of a reflector or subterranean reflecting surface of a formation bed outside a borehole. A monopole transmitter may be used with a monopole/dipole receiver pair, or a monopole transmitter and a dipole transmitter pair may be used with a monopole receiver in accordance with the invention to determine the azimuth position and distance of the reflector. Azimuth resolution is improved through use of multiple receiver elements at equal radius about the longitudinal axis of a borehole tool, or through mathematical rotation of receiver elements.

Abstract: An evaluation system and retest method uses essential coupling physics of lightning, monitored system geometries, and on-line sensor readings for generating and comparing monitored retest indices to critical retest indices using a retest chain algorithm using pre-launch analyses to then provide real-time retest decisions for spacecraft launch operations following major lightning storms.

Abstract: A method of seismic exploration while drilling from within a borehole containing fluid, with a source and receivers positioned in the borehole is provided, comprising detecting small amplitude signals from waves within the fluid. The method is used to identify signals from waves within the fluid known as tube waves that result from compressional waves converted at the bottom of the borehole. The invention also includes seismic detection apparatus comprising ring hydrophones or similar pressure sensors. The apparatus is preferably attached to a coiled tubing with the drill bit actuated by a separate actuator as source.

Abstract: An apparatus and method for obtaining samples of pristine formation or formation fluid, using a work string designed for performing other downhole work such as drilling, workover operations, or re-entry operations. An extendable element extends against the formation wall to obtain the pristine formation or fluid sample. While the test tool is in a standby condition, the extendable element is withdrawn within the work string, protected by other structure from damage during operation of the work string. The test apparatus is mounted on a sliding, non-rotating, sleeve on the work string.