Abstract: The present invention belongs to the field of geophysical exploration, and discloses physical seismic simulation test apparatus and method based on reflected wave field for a hydrate formation. The apparatus comprises a hydrate preparation device and a reflected acoustic wave test device, wherein the hydrate preparation device is configured to generate simulated hydrates, and the reflected acoustic wave test device is configured to continuously emit ultrasonic waves to the simulated hydrates in the generation process, process the received reflected waves to identify and extract reflection characteristic information and acoustic wave velocity change information, and continuously monitor the degree of saturation of the simulated hydrates at the same time to obtain a corresponding relationship between the reflection characteristic information and acoustic wave velocity change information and the degree of saturation of the simulated hydrates.

Abstract: A pulsed sinusoidal acoustic signal transmitted through a subsurface volume of a wellbore may be detected. A time-reversed acoustic signal of the pulsed sinusoidal acoustic signal may be transmitted through the subsurface volume of the wellbore. Transmission of the time-reversed acoustic signal through the subsurface volume of the wellbore may result in generation of focused acoustic signal in the subsurface volume of the wellbore. The focused acoustic signal in the subsurface volume of the wellbore may be detected, and the integrity of the wellbore may be determined based on the focused acoustic signal in the subsurface volume of the wellbore.

Abstract: A seismic streamer includes an outer sheath that forms an interior region of the seismic streamer of which a portion is filled with a gel or liquid. The streamer also includes at least one stress member placed off-center in the interior region, and multiple sensors mounted proximate to a center of the interior region, where the sensors include a pressure sensor and a motion sensor. The streamer further includes multiple tilt sensors mounted along the interior region. A method of manufacturing a seismic streamer includes placing at least one stress member off-center along a first direction, mounting multiple spacers along the stress member, and affixing sensors to respective spacers, where the sensors include a pressure sensor and a motion sensor. The method further includes mounting tilt sensors along the first direction and affixing an outer sheath to the streamer that forms an interior region of the seismic streamer.

Abstract: Apparatus (10) and methods for combining time reversal and elastic nonlinearity of formation materials for qualtitatively probing for over-pressured regions down hole in advance of a well drilling bit, to determine the distance to the over-pressured region, and for accurately measuring pore pressure downhole in a formation, are described. Classical and reciprocal time reversal methods may be utilized to achieve these measurements.

Abstract: Deploying and retrieving streamer cleaning devices. At least some of the example embodiments are methods including transferring a streamer cleaning device to a geophysical sensor streamer. The transferring may include towing the geophysical sensor streamer through water while the geophysical sensor streamer submerged, towing a tow fish through water by way of an umbilical (the streamer cleaning device coupled within a payload area of the tow fish during the towing of the tow fish through the water), landing the tow fish on the geophysical sensor streamer and thereby abutting the streamer cleaning device against the geophysical sensor streamer, closing the streamer cleaning device around the geophysical sensor streamer, releasing the streamer cleaning device from the payload area, and separating the tow fish from streamer cleaning device and the geophysical sensor streamer.

Abstract: An illustrative hydraulic fracture mapping method includes: collecting microseismic signals during a multistage hydraulic fracturing operation; deriving microseismic event locations from the microseismic signals to create a microseismic event map for each stage of the operation; fitting a set of fracture planes to the microseismic event maps; determining a stimulated reservoir volume (“SRV”) region for each said stage; identifying where SRV regions overlap to form an overlap region; partitioning the overlap region to eliminate any overlap between the SRV regions; truncating the set of fracture planes for the SRV regions to discard any portion outside the revised SRV regions; and storing or displaying the truncated set of fracture planes for the first revised SRV region.

Abstract: Seismic data are acquired using a seismic source comprising a plurality of seismic sub-sources disposed in a body of water at a plurality of depths and activated with different time delays. Far-field signatures are determined for the plurality of seismic sub-sources at each of the plurality of depths. A composite ghost-free far-field signature of the seismic source is determined from the far-field signatures for the plurality of seismic sub-sources at each of the plurality of depths and different time delays.

Abstract: A seismic node deployment system comprises a cable supply with one or more seismic nodes configured for coupling to the cable at one or more attachment locations for deployment to a water column. A node attachment system is configured to drive a portion of the cable into periodic or reciprocal motion so that the attachment speed is substantially reduced relative to the speed at which the cable is deployed.

Abstract: Provided are acceleration sensor, geophone and seismic prospecting system with high sensitivity and low power consumption. The acceleration sensor includes a mass body displaceable with respect to a rotation shaft. The acceleration sensor includes a first AC servo control facing a first symmetrical region of the first movable portion, a second AC servo control electrode facing a second symmetrical region of the second movable portion, and a DC servo control electrode facing an asymmetrical region of the second movable portion. A first AC servo capacitive element is formed by the first movable portion and the first AC servo control electrode, a second AC servo capacitive element is formed by the second movable portion and the second AC servo control electrode, and a DC servo capacitive element is formed by the second movable portion and the DC servo control electrode.

Abstract: A method of evaluating a subterranean formation includes conveying a tool along a borehole. The tool includes a transmitter that transmits a drive pulse and a receiver that receives at least one formation response to the drive pulse. The method further includes calculating a signal-to-noise ratio of the at least one formation response and comparing the signal-to-noise ratio to a programmable threshold. The method further includes determining, based on the comparing, an adjusted drive pulse to transmit and transmitting the adjusted drive pulse. The method further includes and receiving at least one formation response to the adjusted drive pulse and deriving formation data from the at least one formation response to the adjusted drive pulse. The method further includes displaying a representation of the formation based on the formation data.

Abstract: An ultrasound transducer may be driven by a driver circuit having one or more charge pumps and a multi-level inverter. The one or more charge pumps are configured to drive the ultrasound transducer only during output transitions of the inverter.

Abstract: The invention relates to a seismic streamer (1) for underwater towing at a towing speed in ice-free or wholly or partially icy water, the streamer (1) is provided with birds (2) spaced along the streamer, the streamer including the birds (2) has negative buoyancy, the birds have wings (8) which can be set so that the birds during movement in the water apply an upward or downward force on the streamer. The streamer (1) is provided with buoyant bodies (4) spaced along the streamer, the buoyant bodies are connected to the streamer by spacer elements (5), the streamer including the birds, the buoyant bodies with associated spacer elements and any other equipment together have positive buoyancy. The invention also relates to a corresponding method for securing a seismic streamer (1) from damage at a substantial reduction or cessation of towing speed when towing underwater in ice-free or wholly or partially icy water.

Abstract: A method of forming an image of a region of interest using a pulse-echo imaging device is described. The method includes the steps of transmitting a pulse, discriminating an echo of the pulse by comparison to a plurality of Hermite polynomials, and determining a color for display based on the comparison. A system for forming an image of a region of interest is also described. The system includes a pulse-echo imaging device for transmitting a pulse and a control unit in communication with the pulse-echo imaging device. The control unit is configured to discriminate an echo of the pulse by comparison to a plurality of Hermite polynomials and determine a color for display based on the comparison.

Abstract: A computer implemented method for identifying reservoir facies in a subsurface region includes obtaining a set of seismic data points of both petrophysical and geophysical parameters relating to the subsurface region, identifying one or more correlated clusters of petrophysical parameters, generating, from the one or more correlated clusters of petrophysical parameters, one or more corresponding multi-dimensional clusters of seismic data points, storing, in a facies database, a multi-dimensional cluster center point for at least one multi-dimensional clusters, and recursively splitting the multi-dimensional clusters into distinct sub-clusters of seismic data points corresponding to facies types.

Abstract: Techniques are disclosed relating to configuring a marine seismic survey. In some embodiments, a vessel may be coupled to one or more seismic sources and one or more seismic streamers, and a second vessel may be coupled to one or more far offset seismic sources. The near offset sources may be configured to actuate according to a shot point interval; the far offset sources may be configured to actuate according to a longer shot point interval. In some embodiments, the longer shot point interval may be a multiple of the near offset source shot point interval. Determining the first and second shot point intervals may be based in part on, for example, the wave frequencies of the far offset sources, the requirements of a full wave inversion process, or various configurational parameters of seismic surveys.

Abstract: Implementations described and claimed herein provide systems, apparatuses, and methods for ultrasonic object detection. In one embodiment, a sensor includes at least two transducers driven by a common waveform generator and configured to process received echoes, from an object, using a common echo detector. By providing the wavefront 180 degrees out of phase to one transducer relative to the other transducer, a dual detection lobe may be provided and thereby provided two detection volumes. By varying the phase delay from one transducer relative to other, the detection beam (volume) may be steered or swept. Without phase delay, a relatively higher strength acoustic detection signal may be transmitted by the two or more transducers.

Abstract: Embodiments relate to noncontact determination of nonlinearities. Initially, a first and second primary signal are preconditioned to produce a first and second tone capable of reaching a target granular media. Using a sound source, the first and second primary signals are emitted such that the first and second primary signals combine in a nonlinear fashion in the target granular media to produce low frequency acoustic tone that is a difference between the first and primary signals. An acoustic pulse is received by an acoustic receiver, and a quadratic nonlinearity coefficient and an acoustic pressure field are determined based on the acoustic pulse. At this stage, a sediment shear strength of the granular media is correlated to the quadratic nonlinearity coefficient to generate a shear strength lookup table.

Abstract: Included are methods and apparatus for marine geophysical surveying. One embodiment of the presently-disclosed solution relates to a method for instantaneous roll compensation of vectorised motion data originating from a fixed-mount geophysical sensor during a marine seismic survey. A streamer is towed behind a survey vessel in a body of water. The streamer includes a plurality of geophysical sensors and a plurality of orientation sensor packages, and each orientation sensor package comprises a magnetometer. Vectorised geophysical data is acquired using the plurality of geophysical sensors, while orientation data is acquired by the plurality of orientation sensor packages. The orientation data is used to determine an instantaneous roll angle of the streamer at different positions on the streamer. The vectorised geophysical data is adjusted to compensate for the instantaneous roll angle of the streamer at different positions on the streamer. Other embodiments and features are also disclosed.

Abstract: A method, including: calibrating a linear rock physics model to well log properties; generating a plurality of pseudo-well models for a subsurface region using a Monte Carlo approach; generating synthetic seismic traces from each of the plurality of pseudo-well models; computing top and base isochron from the synthetic seismic traces; computing seismic attributes in an interval specified by the top and base isochron on the synthetic seismic traces; correlating the seismic attributes to rock properties; and transforming seismic data into low-side, most-likely, and high-side estimates of rock properties.

Abstract: Techniques are disclosed relating to the determination of a warping attribute related to a difference between an up-going pressure wavefield and a down-going pressure wavefield received from a seismic data acquisition system. The warping attribute is used to determine a pseudo up-going or down-going pressure wavefield. The pseudo pressure wavefield is used to generate a modified record of geophysical data, which is stored in a non-transitory memory medium as a geophysical data product.