Halliburton Energy Services, Inc.

System and methods of petrophysical modeling are disclosed. Measurements of formation parameters along a planned path of a wellbore are received during a current stage of a downhole operation. A correlation coefficient between each of the formation parameters and at least one target parameter for the reservoir formation is determined based on the received measurements. Input parameters are selected from among the formation parameters for a symbolic regression model, based on the correlation coefficient calculated for each formation parameter. A symbolic regression model is trained to generate a target petrophysical model, based on the selected input parameters and the corresponding measurements received from the downhole tool. One or more properties of the formation are estimated for a subsequent stage of the downhole operation, based on the generated petrophysical model. The subsequent stage is performed along the wellbore, based on the one or more estimated properties of the reservoir formation.

A method that may include disposing an electromagnetic (EM) logging tool in a wellbore. The EM logging tool may include one or more transmitters disposed on the EM logging tool and one or more receivers disposed on the EM logging tool. The method may further include transmitting an electromagnetic field from the transmitter into one or more tubulars to energize the one or more tubulars with the electromagnetic field thereby producing an eddy current that emanates from the one or more tubulars, measuring the eddy current in the one or more tubulars with the receiver on at least one channel to obtain a plurality of measurements, and forming an EM log from the plurality of measurements.

A method that may include disposing an electromagnetic (EM) logging tool in a wellbore. The EM logging tool may include one or more transmitters disposed on the EM logging tool and one or more receivers disposed on the EM logging tool. The method may further include transmitting an electromagnetic field from the transmitter into one or more tubulars to energize the one or more tubulars with the electromagnetic field thereby producing an eddy current that emanates from the one or more tubulars, measuring the eddy current in the one or more tubulars with the at least one receiver on at least one channel to obtain a plurality of measurements and sending the plurality of measurements to an information handling system. The information handling system may be configured to utilize a multi-dimensional computational model to simulate sensor responses and may apply an inversion to estimate one or more anomaly parameters.

Methods and systems herein may perform nuclear magnetic resonance measurements, and nuclear magnetic resonance tools, the method and systems comprising: acquiring, using an NMR sensor a first NMR signal from a volume in a subterranean region, wherein the first NMR signal is acquired using a first acquisition window. Further, acquiring, using the NMR sensor a second NMR signal from a volume in the subterranean region, wherein the second NMR signal is acquired using a second acquisition window different from the first acquisition window, wherein the first NMR signal and the second NMR signal form an NMR relaxation data; determining, using the first NMR signal and the second NMR signal, a correction term. Finally, the correction term may be used to acquire a corrected relaxation data set.

A method that includes disposing an acoustic logging tool in a borehole. The acoustic logging tool comprises one or more transmitters and one or more receivers. The method may further comprise taking one or more acquisitions with the acoustic logging tool as the acoustic logging tool traverses through the borehole, creating an azimuth rotation angle array of one or more angles, from the one or more acquisitions, and applying a trial angle selected from the one or more angles of the azimuth rotation angle array to calculate a fast shear waveform.

Systems, methods, and apparatus, including computer programs encoded on computer-readable media, for obtaining nuclear magnetic resonance (NMR) measurements of a subsurface formation in a well system. One or more NMR pulses are generated downhole using an NMR tool of the well system. It is determining whether an amplitude of an NMR echo signal is less than or equal to a threshold level or the NMR echo signal is not present. Ringing noise associated with the one or more NMR pulses is measured when the amplitude of the NMR echo signal is less than or equal to the threshold level or the NMR echo signal is not present. The ringing noise is cancelled from the NMR measurements, and properties of the subsurface formation are determined from the NMR measurements after cancelling the ringing noise.

Provided, in one aspect, is a method comprising receiving data of measurements from a distributed sensing system having sensors distributed along different depths of a wellbore formed in a subsurface formation; and performing signal processing of the data to output a number of modes, wherein each mode includes a subset of the data that quantifies behavior of at least one of a fluid in the subsurface formation and a rock in the subsurface formation on a different combination of locations in the wellbore and timing of the measurements.

System and methods for geosteering inversion are provided. Downhole tool responses are predicted for different points along a planned path of a wellbore during a downhole operation, based on each of a plurality of inversion models. Measurements of the downhole tool's actual responses are obtained as the wellbore is drilled over the different points during a current stage of the operation. The inversion models are then clustered using a weighted clustering approached in which a weighted score system is formulated to apply a standard deviation, number of models, and/or misfit of each cluster as key parameters, and used to evaluate the clusters accordingly. The corresponding scores are computed and used to select clusters. The planned wellbore path is adjusted for the subsequent stage(s) of the downhole operation.

A method of deploying a pulsed neutron logging tool. The method may comprise detecting natural gamma rays from the subterranean formation via one or more detectors of the pulsed neutron logging tool, broadcasting neutrons into the subterranean formation, and detecting neutron-induced gamma rays and natural gamma rays from the subterranean formation. The method may further comprise creating an inelastic spectrum, a capture spectrum, or a capture time decay from the natural gamma rays or the neutron-induced gamma rays, forming an inelastic yields, a capture elemental yields, or a formation sigma form the inelastic spectrum, the capture spectrum, or the capture time decay, creating a closure model from the inelastic yields and/or capture elemental yields and/or a formation sigma, and identifying a porosity, a mineral weight fraction, or a quality figure of merit from the closure model that quantifies geologic hydrogen reservoir quality.

Aspects of the subject technology relate to systems, methods, and computer-readable media for synthesizing sonic logs for downhole environments. Data associated with a wellbore in a formation is accessed. A model configured to identify one or more characteristics associated with sound traveling through one or more formation is accessed. The data is applied to the model to predict a characteristics of the formation that is identifiable through sonic logging.