Abstract: Borehole sensor apparatus and methods. The borehole sensor apparatus includes at least one sensor and a first elastomer portion in operable contact with the at least one sensor and configured to be connected to a production tube of a borehole.

Abstract: Method and device for performing vertical seismic profiling (VSP) in a borehole with a seismic device (10) comprising an elongated cable (20) with conductors (30) for transporting power and at least one communication line (40) for carrying signals. The device further comprises at least one connection point (50) placed along the elongated cable (20), where the connection point (50) comprises wireless power providing means (60) and communication means (65) that are connected to said conductors (30) and communication line (40) in the elongated cable (20), and at least one sealed seismic module (70) fixed to the at least one connection point (50), the seismic module (70) comprises a geophone (75), electronics (80) for detecting and transferring seismic signals, power receiving means (85) for wirelessly receiving power from the connection point (50) and means for wirelessly transmitting seismic signals to the communication line (40) via the communication means (65) comprised in the connection point (50).

Abstract: A method for estimating parameters of a propagating wave field, such as the direction of propagation in 3D space of an acoustic wave from borehole-acoustic data. The estimation technique uses phase delays between recordings made by the individual receivers related to a plane wave travelling across the receiver array. The estimated plane waves include the wave field generated directly by the acoustic source, as well as refracted and reflected components of these fields. The technique can be used with overlapping wave fields. This will provide significant improvements in the quality of formation properties estimated from full-waveform data that are obtained either from wireline or from while-drilling sonic data. The inventive method enables characterization of abnormalities outside multiple casing strings where acoustic signals are transmitted from a source located inside said multiple casing string.

Abstract: An exploration paradigm for detecting and/or characterizing gas hydrate deposits using either electromagnetic or seismic surveys, that accounts for the possibility that gas hydrate may accumulate in vertical or subvertical dikes. Geologic factors, such as the presence of the gas hydrate stability zone, indications that a prolific source of gas exists (or existed) below the gas hydrate stability zone and indications that a high flux of gas could be transported into the gas hydrate stability zone, may be considered as part of an exploration strategy. Data may be collected using seismic techniques, such as a walk-away vertical seismic profile techniques, or electromagnetic surveys that are adapted to detecting the presence of vertical or subvertical dikes. In one example, data processing and acquisition techniques may be adapted to detect hydrate dikes, and do not assume a horizontally isotropic earth model.

Abstract: A method for estimating parameters of a propagating wave field, such as the direction of propagation in 3D space of an acoustic wave from borehole-acoustic data. The estimation technique uses phase delays between recordings made by the individual receivers related to a plane wave travelling across the receiver array. The estimated plane waves include the wave field generated directly by the acoustic source, as well as refracted and reflected components of these fields. The technique can be used with overlapping wave fields. This will provide significant improvements in the quality of formation properties estimated from full-waveform data that are obtained either from wireline or from while-drilling sonic data. The inventive method enables characterization of abnormalities outside multiple casing strings where acoustic signals are transmitted from a source located inside said multiple casing string.

Abstract: A technique facilitates performance of seismic profiling, such as three-dimensional vertical seismic profiling. A downhole acquisition system is provided with acoustic receivers designed to receive acoustic source signals. The firing of acoustic source signals is synchronized with the downhole acquisition system. Additionally, the firing of two or more acoustic source signals is controlled to provide simultaneous or nearly simultaneous timing of one acoustic source signal with respect to another acoustic source signal. A processing system is used to acquire and process a data stream of the initial shot and a data stream of the additional shot occurring simultaneously or nearly simultaneously.

Abstract: A method of acquiring seismic data that includes deploying a first array of seismic receivers and a second array of seismic receivers, and simultaneously receiving drill noise seismic energy produced as a wellbore is drilled relatively near the first and second arrays of seismic receivers using the first and second array of seismic receivers, wherein the first array of seismic receivers is closer to the source of the drill noise seismic energy than the second array of seismic receivers. A related method for processing seismic data and computer useable media are also described. Also a method of acquiring seismic data that includes deploying a first array of seismic receivers within a borehole, receiving seismic energy produced as a wellbore is drilled relatively near first array using said seismic receivers, and recording seismic data associated with the received seismic energy. A related method for acquiring and processing seismic data is also described.

Abstract: A method of processing seismic data obtained using a seismic vibrator that includes estimating travel times of direct wave arrivals between the seismic vibrator and an array of seismic receiver locations and wavefield deconvolving the seismic data using the direct wave arrival travel times. Also a related method of producing a high-frequency geological subsurface image that includes acquiring seismic data having significant harmonic energy using a seismic vibrator, estimating direct wave arrival travel times between the seismic vibrator and an array of seismic receiver locations, wavefield deconvolving the seismic data using the estimated direct wave arrival travel times, and using the wavefield deconvolved seismic data to produce a high-frequency geological subsurface image. A further related computer useable medium having computer readable program code means embodied therein practicing the inventive method.

Abstract: A method of processing sonic wireline or logging while drilling data acquired in a borehole that includes filtering the sonic data to attenuate tool-borne and borehole-borne arrivals; migrating the filtered sonic data; and beamforming the filtered and migrated sonic data to determine a position of a reflector with respect to the borehole. The sonic data may be processed down-hole, transmitted to the surface, and used for geosteering purposes while drilling. The filter may comprise an adaptive noise-attenuating filter capable of attenuating noise arising from different borehole modes from desired signal and allowing for changes in the source signature.

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 of processing sonic wireline or logging while drilling data acquired in a borehole that includes filtering the sonic data to attenuate tool-borne and borehole-borne arrivals; migrating the filtered sonic data; and beamforming the filtered and migrated sonic data to determine a position of a reflector with respect to the borehole. The sonic data may be processed down-hole, transmitted to the surface, and used for geosteering purposes while drilling. The filter may comprise an adaptive noise-attenuating filter capable of attenuating noise arising from different borehole modes from desired signal and allowing for changes in the source signature.

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: Method of vertical seismic profiling in drilling operations utilizing the drill bit for a source of seismic energy without any break in drilling operations. The noise of the drill bit and reflections of the noise in the formation are recorded with the aid of a geometrically extended array of receivers which are provided in a predetermined matrix group. The received signals are analyzed according to velocity and migration principles per se on the basis of differences in reception times, by which the noise signature of the drill bit can be determined at any desired location during drilling operations and extracted from the traces. The remaining received signal frequencies and signal amplitudes are analyzed in relation to their deviation in time, the signals being grouped according to time differences corresponding to focusing on certain areas in the formation.