A method of identifying inflow locations along a wellbore includes obtaining an acoustic signal from a sensor within the wellbore, determining a plurality of frequency domain features from the acoustic signal, and identifying, using a plurality of fluid flow models, a presence of at least one of a gas phase inflow, an aqueous phase inflow, or a hydrocarbon liquid phase inflow at one or more fluid flow locations. The acoustic signal includes acoustic samples across a portion of a depth of the wellbore, and the plurality of frequency domain features are obtained across a plurality of depth intervals within the portion of the depth of the wellbore. Each fluid flow model of the plurality of fluid inflow models uses one or more frequency domain features of the plurality of the frequency domain features, and at least two of the plurality of fluid flow models are different.

A method of seismic acquisition using a dispersed-source array (DSA) comprising two or more sources. The method comprises determining, for each of the two or more sources of the DSA, an individual spectrally-banded waveform. For each of the two or more sources, a primary waveform is formed by repeating the individual spectrally-banded waveform. For each of the two or more sources, a secondary waveform is formed based on the primary waveform. The secondary waveform is spectrally shifted relative to the primary waveform such that secondary waveforms of any two of the two or more sources are spectrally non-overlapping. The blending operator based on the secondary waveform of each of the two or more sources is provided to the DSA. The method also includes performing deblended-data reconstruction of acquired seismic data using one or more properties of the blending operators of the two or more sources.

Systems, methods, and computer-readable media are provided for detecting sand in a production flow. An example method can include receiving acoustic field data generated by at least one acoustic sensor on a downhole tool lowered into a borehole of a production flow. The method can further include inputting the acoustic field data into an acoustic sand detection model and generating a sand flow signal based on output on the acoustic sand detection model.

Techniques for calculating and visually presenting multiple acoustic modes that have different formation slowness are disclosed herein. The techniques include methods for receiving time-domain waveforms from adjacent formations in a borehole, processing each of the time-domain waveforms to generate frequency-domain spectrums, selecting frequency and slowness values, and predicting travel time of a mode associated with the slowness value. In some aspects, the method further includes steps for calculating a semblance difference of the frequency-domain spectrums based on the frequency value, the slowness value and the predicted travel time. Systems and computer-readable media are also provided.

A system and method combines model-based inversion and supervised neural networks to develop high resolution rock property volumes from surface seismic data. These volumes have higher frequency and are calibrated to fit well log data. In addition to rock volumes, a Reflection Coefficient (RC) volume is derived from the acoustic impedance volume. The RC volume has much higher frequency, better lateral continuity, and ties to the well logs better than conventional seismic or frequency enhanced data. By interpreting and mapping with this RC volume, a much more accurate depth model can be built, which allows for a horizontal well to be accurately drilled.

A method, apparatus, and program product analyze time-series data such as seismic data collected from a subsurface formation by splitting a time-series data set such as an individual seismic trace into a plurality of spectral components, each having an associated frequency, determining an instantaneous frequency for each spectral component, determining a frequency difference for each spectral component based at least in part on the associated and instantaneous frequencies therefor, and determining a tuning parameter based at least in part on the determined frequency difference of each spectral component. Doing so enables, for example, thin-bed structures in the subsurface formation to be identified, and in some instances, thicknesses of such structures to be determined.

A high-resolution processing method for seismic data based on inverse multi-resolution singular value decomposition includes the steps of: step 1: obtaining a single-trace seismic signal X as a raw signal; step 2: decomposing the seismic signal by using MRSVD algorithm to obtain a series of detailed singular values and inversely recursing the detailed singular values layer by layer to obtain a new detailed signal and an approximate signal; and step 3: sequentially superimposing the new detailed signal on the raw signal, layer by layer, to compensate the high-frequency component of the seismic signal so as to obtain a high-resolution seismic signal.

Seismic data obtained from a seismic survey conducted of a subterranean region is received. The seismic data includes multiple frequency components, having a frequency bandwidth. A target, to-be-picked horizon is identified by displaying well data on the seismic section and correlating the seismic reflector with layer tops in the well data. A horizon represents a seismic reflector between two geological layers in the subterranean region. A single frequency that gives rise to a predetermined continuity along the target horizon is determined from the frequency bandwidth of the seismic data. The seismic data is filtered to mono-frequency volumes. The mono-frequency seismic volumes include a single frequency component. A horizon is picked corresponding to the target horizon based on the mono-frequency volumes. The identified horizon corresponding to the target horizon is output for determining geological features of the subterranean region based on the identified horizon.

An apparatus for detecting a location of an optical fiber having an acoustic sensor disposed subsurface to the earth includes an acoustic emitter configured to emit a first signal having a first frequency and a second signal having a second frequency that is higher than the first frequency, the first and second emitted acoustic signals being azimuthally rotated around the borehole and an optical interrogator configured to interrogate the optical fiber to receive an acoustic measurement that provides a corresponding first received signal and a corresponding second received signal. The apparatus also includes a processor configured to (i) frequency-multiply the first received signal to provide a third signal having a third frequency within a selected range of the second frequency, (ii) estimate a phase difference between the second received signal and the third signal, and (iii) correlate the phase difference to the location of the optical fiber.

The instant invention relates to a method for noise reduction from a magnetic resonance sounding (MRS) oscillating signal, and more particularly, to a data processing method for reducing random noise contained in MRS oscillating signal based on joint algorithm principles of EMD and TFPF. A MRS oscillating signal is decomposed into different eigen-mode components by using decomposition characteristic of EMD algorithm; then a signal-dominated eigen-mode component is encoded as an instantaneous frequency of an analytical signal of unit amplitude using TFPF algorithm; and random noise is suppressed with the characteristics that the time-frequency distribution of the analytical signal is concentrated along with the instantaneous frequency. The method requires fewer filtering constraints and is simple to operate without need of designing a filtering interval in the time-frequency domain, and has good adaptability to the MRS oscillating signal with a low signal-noise-ratio.