This disclosure is related to hydrophones, for example hydrophones that may be used in marine seismic surveying, permanent reservoir monitoring, downhole acoustic monitoring in a wellbore, and/or various other applications. Some embodiments of a hydrophone according to this disclosure are constructed such that a longitudinal stiffness of the hydrophone is greater than a circumferential stiffness of the hydrophone. In some embodiments, however, the longitudinal stiffness may be somewhat less than the circumferential stiffness. For example, the longitudinal stiffness may be greater than one half the circumferential stiffness in some cases.

A method for transmitting data from a downhole location to a location at the surface of the earth includes determining a minimum value and a maximum value of M-samples of data values, determining a keycode for the M-samples of data values that provides an indication of the maximum and minimum values of the M-samples, and encoding the keycode and the data values into one or more encoded words. The one or more encoded words are then transmitted as an acoustic signal in drilling fluid by modulating a mud-pulser. The acoustic signal is received by a transducer uphole from the mud-pulser and converted into an electrical signal. The electrical signal is demodulated into a received encoded word, which is decompressed into the M-samples in accordance with the keycode. The M-samples are then received by a computer processing system disposed as the surface of the earth.

The present invention concerns a method for processing well data from a well. The method comprises: receiving, for each current facies, a presence probability distribution of said current facies, depending on a parameter influencing sedimentation. For each current measurement, and in a space comprising at least a first axis and a second axis, determining at least one point having, as a coordinate along the first axis, said current measurement, and as a coordinate along the second axis, a value of the parameter, determined depending on the presence probability distribution of the facies associated with the current measurement in the received well data. The method further comprises determining a curve in the space depending on at least one point for each measurement of the plurality of measurements.

A system and method for predictive flow assurance assessment by measuring at least one actual parameter related to a multiphase fluid mixture flowing in a main flow line, taking a sample from the multiphase fluid mixture flowing in the main flow line, modifying at least one control parameter of the sample until a transition appears, wherein said transition would cause a flow issue when occurring in the main flow line, detecting the transition of the sample and determining a corresponding transition value associated with the at least one control parameter, calculating a difference between the at least one actual parameter and the at least one transition value, said difference being representative of a margin relatively to a similar transition appearance in the main flow line causing a flow issue in the main flow line, and implementing a flow issue preventing step when the difference exceeds a given threshold.

An acoustic logging tool includes a first acoustic transducer and a second acoustic transducer. At least a portion of the first transducer is parallel with the second transducer. The first and second acoustic transducers are configured to propagate an acoustic signal in the same direction. The first acoustic transducer is configured to generate an acoustic output having a different frequency than the second acoustic transducer.

An acoustic logging tool includes a first acoustic transducer and a second acoustic transducer. At least a portion of the first transducer is parallel with the second transducer. The first and second acoustic transducers are configured to propagate an acoustic signal in the same direction. The first acoustic transducer is configured to generate an acoustic output having a different frequency than the second acoustic transducer.

An example method for displaying sonic logging data associated with a formation surrounding a borehole can include acquiring sonic data at a plurality of depths using an acoustic array located in the borehole and transforming the acquired sonic data from a time-space domain to a frequency-wave number domain at a limited number of discrete frequencies. The method can also include estimating slowness values at the limited number of discrete frequencies from the transformed sonic data, interpolating the estimated slowness values to obtain a projection of one or more slowness-frequency dispersions of the acquired sonic data and displaying the projection of the slowness-frequency dispersions. The projection of the slowness-frequency dispersions can include a plurality of color bands corresponding to each of the limited number of discrete frequencies.

An example method for displaying sonic logging data associated with a formation surrounding a borehole can include acquiring sonic data at a plurality of depths using an acoustic array located in the borehole and transforming the acquired sonic data from a time-space domain to a frequency-wave number domain at a limited number of discrete frequencies. The method can also include estimating slowness values at the limited number of discrete frequencies from the transformed sonic data, interpolating the estimated slowness values to obtain a projection of one or more slowness-frequency dispersions of the acquired sonic data and displaying the projection of the slowness-frequency dispersions. The projection of the slowness-frequency dispersions can include a plurality of color bands corresponding to each of the limited number of discrete frequencies.

One embodiment includes receiving distributed acoustic sensing (DAS) data for responses associated with seismic excitations in an area of interest. The area of interest includes a sea surface, the water column, a seafloor, and a subseafloor. The seismic excitations are generated by at least one seismic source in the area of interest. The responses are detected by at least one fiber optic sensing apparatus configured for DAS that is in the water column, on the seafloor, in a wellbore drilled through the seafloor and into the subseafloor, or any combination thereof. The embodiment includes determining a function of speed of sound in water using the DAS data, and correcting a digital seismic image associated with the area of interest using the function of speed of sound in water to generate a corrected digital seismic image.

Methods and mediums for estimating stimulated reservoir volumes are disclosed. Some method embodiments may include obtaining microseismic event data acquired during a hydraulic fracturing treatment of the formation, the data including event location and at least one additional attribute for each microseismic event within the formation; filtering the microseismic events based on the at least one additional attribute; determining a density of filtered microseismic events; weighting the filtered microseismic events based on the density; and determining a stimulated reservoir volume estimate based on filtered and weighted microseismic events.