Systems and methods are provided for obtaining a flexural-attenuation measurement for cement evaluation that may be effective even for wells with relatively thick casings. A method includes emitting an acoustic signal at a casing in a well that excites the casing into generating an acoustic response signal containing acoustic waves, such as Lamb waves. The Lamb waves include flexural waves and extensional waves. The casing may be relatively large, having a thickness of at least 16 mm. The acoustic response signal may be detected and filtered to reduce a relative contribution of the extensional waves. This may correspondingly increase a relative contribution of the flexural waves. The filtered acoustic response signal may be used as a flexural-attenuation measurement for cement evaluation.

A method for evaluating one or more bottom hole assemblies (BHAs) includes receiving a plurality of inputs. The inputs include one or more properties of the one or more BHAs, a planned trajectory of a wellbore, and one or more properties of a subterranean formation into which the wellbore will be drilled. The method also includes simulating drilling the wellbore in the subterranean formation based at least partially upon the inputs. Drilling of the wellbore is simulated with one or more artificial intelligence (AI) agents. Drilling of the wellbore is simulated a plurality of times using each of the one or more BHAs, thereby producing a plurality of simulations. Each simulation is generated using a different one of the AI agents. The method also includes generating one or more outputs in response to simulating drilling the wellbore.

Methods of characterizing acoustic output from a hydrocarbon well and hydrocarbon wells that include controllers that perform the methods are disclosed herein. The methods include receiving the acoustic output, determining a plurality of acoustic fingerprints, and electronically clustering the plurality of acoustic fingerprints. The acoustic output includes information regarding a plurality of sound events, and each sound event of the plurality of sound events includes at least one corresponding sound detected at the hydrocarbon well. The plurality of acoustic fingerprints includes a corresponding acoustic fingerprint for each sound event of the plurality of sound events. The electronically clustering includes utilizing a clustering algorithm to generate a plurality of acoustic event clusters. Each acoustic event cluster of the plurality of acoustic event clusters includes a corresponding fingerprint subset of the plurality of acoustic fingerprints, and each acoustic fingerprint in the corresponding fingerprint subset includes at least one similar acoustic property.

Methods of characterizing acoustic output from a hydrocarbon well and hydrocarbon wells that include controllers that perform the methods are disclosed herein. The methods include receiving the acoustic output, determining a plurality of acoustic fingerprints, and electronically clustering the plurality of acoustic fingerprints. The acoustic output includes information regarding a plurality of sound events, and each sound event of the plurality of sound events includes at least one corresponding sound detected at the hydrocarbon well. The plurality of acoustic fingerprints includes a corresponding acoustic fingerprint for each sound event of the plurality of sound events. The electronically clustering includes utilizing a clustering algorithm to generate a plurality of acoustic event clusters. Each acoustic event cluster of the plurality of acoustic event clusters includes a corresponding fingerprint subset of the plurality of acoustic fingerprints, and each acoustic fingerprint in the corresponding fingerprint subset includes at least one similar acoustic property.

A method comprises receiving a current dataset for a current time window from at least one sensor in a wellbore created in a subsurface formation, wherein the current dataset comprises values of a number of current features of the subsurface formation at a spatial location in the wellbore. The method includes selecting at least one previous time window from a number of previous time windows that includes a previously cached dataset that was detected by the at least one sensor or a different sensor in the wellbore and that spatially overlaps with the spatial location for the current dataset. The method includes merging the current dataset with the previously cached dataset to create a merged dataset. The method includes selecting a machine learning model from a plurality of machine learning models for the spatial location in the wellbore based on the merged dataset.

Systems and methods for determining perforation orientations of a subterranean formation for a hydraulic fracturing treatment are presented. The method comprises identifying in-situ stresses for a portion of a wellbore formed from a terranean surface into a subterranean formation. The method also includes transforming the in-situ stresses from a global coordinate system to a wellbore coordinate system at a perforation cluster of the wellbore that comprises at least one perforation tunnel for a hydraulic fracturing treatment. The in-situ stresses are transformed from the wellbore coordinate system to a perforation coordinate system through at least one rotation matrix. Pressure coefficients and a breakdown pressure for each trial perforation phase angle at a perforation cluster determined, and a perforation point in the wellbore coordinate system is calculated for each trial perforation phase angle of the perforation cluster. The perforation point in the wellbore coordinate system is transformed to the translated global coordinate system for each trial perforation phase angle. A target perforation phase angle is selected at a minimum breakdown pressure for the perforation cluster, and a perforation azimuth and perforation dip is calculated for the perforation cluster at the minimum breakdown pressure for the target perforation phase angles.

A solid-state hydrophone may include a piezoelectric rod positioned between at least two electrodes. The piezoelectric rod may be disposed within a metallic housing to shield the piezoelectric rod and its connections from acoustic and electromagnetic waves. The piezoelectric rod and the electrodes may be potted in the mechanical housing using a potting material that may be positioned adjacent to the piezoelectric rod. At least a layer of the potting material may be positioned between the piezoelectric rod and the metallic housing to physically separate the piezoelectric rod from the metallic housing.

A solid-state hydrophone may include a piezoelectric rod positioned between at least two electrodes. The piezoelectric rod may be disposed within a metallic housing to shield the piezoelectric rod and its connections from acoustic and electromagnetic waves. The piezoelectric rod and the electrodes may be potted in the mechanical housing using a potting material that may be positioned adjacent to the piezoelectric rod. At least a layer of the potting material may be positioned between the piezoelectric rod and the metallic housing to physically separate the piezoelectric rod from the metallic housing.

There is described a method of making an acoustic sensor having a frequency response approximating a desired frequency response. The method comprises wrapping optical fiber around a core according to a wrapping pattern. The wrapping pattern is determined from an impulse response of the acoustic sensor. The impulse response is determined from the desired frequency response of the acoustic sensor.

There is described a method of making an acoustic sensor having a frequency response approximating a desired frequency response. The method comprises wrapping optical fiber around a core according to a wrapping pattern. The wrapping pattern is determined from an impulse response of the acoustic sensor. The impulse response is determined from the desired frequency response of the acoustic sensor.