Abstract: A method for determining discharge area in hydraulic stimulation operations is provided that includes obtaining one or more treatment data inputs from a well system, and determining a discharge area by applying the one or more treatment data inputs to a function that determines discharge area in terms of volumetric flow rate of the fracturing fluid, wherein the discharge area is a total area of all downhole exits through which the fracturing fluid exits a wellbore into a subterranean formation.

Abstract: A driver for driving a switched-mode power supply is presented. The driver receives a set of input signals. Each input signal is configured for changing a state of an associated power switch from a first state to a second state. The driver generates an output signal to change the state of the associated power switch from the first state to the second state. When the first state is an on state and the second state is an off state, the driver asserts the output signal to change the state of the associated power switch to perform an on-off transition. When the first state is the off state and the second state is the on state, the driver delays the assertion of the output signal to perform an off-on transition by a predetermined delay time, so that the off-on transition is delayed until all intended on-off transitions have occurred.

Abstract: Aspects of the subject technology relate to determining a holdup measurement based on a gamma spectrum through machine learning. A spectral image based on a gamma spectrum generated downhole in a wellbore can be accessed. A component of a holdup measurement for the wellbore can be classified into a specific quantized level through application of a machine learning classification model to the spectral image. A continuous value for the component of the holdup measurement for the wellbore can be quantified by applying a machine learning quantization model associated with the quantized level.

Abstract: Through-tubing, cased-hole sealed material density can be evaluated using gamma ray measurements. Density evaluation comprises detecting, by at least one detector positioned within a casing of a wellbore including a sealing material positioned between the casing and a subsurface formation, electromagnetic radiation generated in response to nuclear radiation being emitted outward toward the subsurface formation, determining an electromagnetic radiation count based on the detected electromagnetic radiation, selecting at least one of a first reference material having a density that is less than a density of the sealing material and a second reference material having a density that is greater than the density of the sealing material, adjusting the electromagnetic radiation count based on the density of the at least one of the first reference material and the second reference material, and determining a density of the sealing material based on the adjusted electromagnetic radiation count.

Abstract: A method for evaluating a sealing material positioned between a casing of a wellbore and a subsurface formation in which the wellbore is formed includes emitting an acoustic waveform outward from a position within the casing and detecting a return waveform that is generated in response to the acoustic waveform interacting with a region of interest that includes at least a portion of the sealing material. The method includes determining a first time window of the return waveform associated with the region of interest and trimming the return waveform based on the first time window. The method further includes determining a first spectral power density for the first time window of the trimmed return waveform and determining a composition ratio for the region of interest based on the first spectral power density.

Abstract: A method and system for identifying one or more petrophysical properties in a formation. The method and system may include disposing a pulsed-neutron logging tool into a borehole that is disposed in a formation, emitting a neutron from a neutron source on the pulsed-neutron logging tool into the formation, and capturing one or more gammas expelled from formation in response to the neutron from the neutron source to form a plurality of pulsed neutron logging (PNL) measurements in a log. The method and system may further include comparing the log to a database with a cost function to form a solution; and identifying a plurality of petrophysical properties based at least in part on the solution.

Abstract: A heater including a ceramic heater element and ceramic heat sink whereby the ceramic heater element and the ceramic heat sink are both formed from a plurality of layers of tape cast ceramic material. The ceramic heater element may be generally planar and extends within a first plane. The ceramic heat sink may extend in a second plane which is orthogonal to the first plane. The ceramic heat sink may include a plurality of fins which may be discrete. The layers of the ceramic heater element may be orientated orthogonal to the layers of the ceramic heat sink. The ceramic heater element may comprise a conductive track which may be surface mounted to a distal side of the ceramic heater element than the ceramic heat sink or embedded within the ceramic heater element.

Abstract: In some embodiments, a method includes emitting, from a transmitter positioned in a wellbore formed in a subsurface formation, a pulse of neutrons into the subsurface formation and detecting gamma ray emissions at a near field and a far field generated in response to the pulse of neutrons being emitted into the subsurface formation. The method includes determining a single elemental decay for one chemical element of a number of chemical elements present in the subsurface formation based on the gamma ray emissions and determining at least one geophysical property of the subsurface formation based on the single elemental decay of the one chemical element.

Abstract: A unified framework has been designed to create and maintain a set of adaptable general models that can be deployed and efficiently trained to fit to various deployments. The unified framework incrementally fills the feature space of a high dimensionality training dataset with field observations to reduce sparseness, trains and retrains a model set with the changing global training dataset, and then deploys a selected adaptable general model for training/fitting to a specified deployment scenario. Data that is generated by deployment adapted models can be validated and then added to the global training dataset that is used to train and update the general models. With the increasing density of the global training dataset, the general models can more quickly converge for a deployment scenario.

Abstract: In some embodiments, a method includes emitting, from a transmitter positioned in a wellbore formed in a subsurface formation, a pulse of neutrons into the subsurface formation and detecting gamma ray emissions at a near field and a far field generated in response to the pulse of neutrons being emitted into the subsurface formation. The method includes determining a single elemental decay for one chemical element of a number of chemical elements present in the subsurface formation based on the gamma ray emissions and determining at least one geophysical property of the subsurface formation based on the single elemental decay of the one chemical element.

Abstract: Systems and methods may utilize information collected by a pulsed-neutron logging tool along with modeling a characterization of a borehole to form a 3-stage correction algorithm. This algorithm may be used to find an oil, water, and gas holdup in the borehole. During operations, a pulsed neutron logging tool which emits neutrons to interact with nuclei inducing gamma radiation. The gamma radiation is detected into a response which may be correlated to the location of a holdup in a borehole by using the entire spectrum or ratios of selected peaks. In examples, a borehole density index may be implemented to complement the response and improve accuracy and measurement confidence.

Abstract: This disclosure presents systems and processes to collect elemental composition of target fluid and solid material located downhole of a borehole. Waveguides can be utilized that include capillary optics to deliver emitted high energy into a container or a conduit and then to detect the high energy. A source waveguide can be used to emit the high energy into the target fluid and a detector waveguide can collect resulting measurements. Each waveguide can include a protective sheath and a pressure cap on the end of the capillary optics that are proximate the target fluid, to protect against abrasion and target fluid pressure. In other aspects, a pulsed neutron tool can be utilized in place of the waveguides to collect measurements. The collected measurements can be utilized to generate chemical signature results that can be utilized to determine the elemental composition of the target fluid or of the solid material.

Abstract: A device for shifting the phase of an electrical signal includes a first microstrip, a second microstrip, and a ground plate. The first microstrip includes an input terminal and the second microstrip includes an output terminal. The second microstrip is spaced apart from the first microstrip such that a microstrip-to-slot transition region is defined between the first microstrip and the second microstrip. The ground plate includes a ground-plate slot that spans the microstrip-to-slot transition region. The ground plate is coupled with the first microstrip and the second microstrip such that at least one of the first microstrip and the second microstrip are movable relative to each other and to the ground plate to adjust a width of the microstrip-to-slot transition region.

Abstract: Systems and methods employed measure borehole density by neutron induced gammas using a pulsed neutron tool. Traditional nuclear density methods only measure a bulk average density of the surrounding material. As discussed below, methods to measure only the borehole density excluding the contamination from the formation are disclosed. Specifically, the proposed methods use unique signatures from each geometric region to directly measure the borehole density or compensate for the contamination from formation. This method may be achieved by a borehole density measurement using differential attenuation of capture gamma from casing iron, a borehole density measurement using differential attenuation of inelastic gamma from oxygen, a differential attenuation of any induced gamma from any element from borehole and formation, or any combination thereof.

Abstract: Systems and methods for determining holdup in a wellbore using a neutron-based downhole tool. In examples, the tool includes nuclear detectors that may measure gammas induced by highly energized pulsed-neutrons emitted by a generator. The characteristic energy and intensity of detected gammas indicate the elemental concentration for that interaction type. A detector response may be correlated to the borehole holdup by using the entire spectrum or the ratios of selected peaks. As a result, measurements taken by the neutron-based downhole tool may allow for a two component (oil and water) or a three component (oil, water, and gas) measurement. The two component or three component measurements may be further processed using machine learning (ML) and/or artificial intelligence (AI) with additional enhancements of semi-analytical physics algorithms performed at the employed network's nodes (or hidden layers).

Abstract: This disclosure presents systems and processes to collect elemental composition of target fluid and solid material located downhole of a borehole. Waveguides can be utilized that include capillary optics to deliver emitted high energy into a container or a conduit and then to detect the high energy. A source waveguide can be used to emit the high energy into the target fluid and a detector waveguide can collect resulting measurements. Each waveguide can include a protective sheath and a pressure cap on the end of the capillary optics that are proximate the target fluid, to protect against abrasion and target fluid pressure. In other aspects, a pulsed neutron tool can be utilized in place of the waveguides to collect measurements. The collected measurements can be utilized to generate chemical signature results that can be utilized to determine the elemental composition of the target fluid or of the solid material.

Abstract: The present disclosure relates to systems and methods of determining a wellbore position in a subterranean formation by using gravity sensors to detect a gravity anomaly related to a presence of the wellbore, contents within the wellbore, and or fluid flowing through an interface of the wellbore. A model of the subterranean formation predicts a gravity profile, including the gravity anomaly, and the model may be constrained with a depth of the gravity anomaly as calculated with at least one of a known dimension or a known gravitational field change related to the gravity anomaly. The wellbore position is determined within the model by changing model input data until the gravity profile converges with the gravity anomaly.

Abstract: Systems and methods of the present disclosure relate to determining a borehole holdup. A method comprises logging a well with a pulsed-neutron logging (PNL) tool; receiving, via the PNL tool, transient decay measurements, capture spectrum measurements, and inelastic spectrum measurements; extracting information from each of the capture spectrum measurements, the inelastic spectrum measurements, and the transient decay measurements; inputting all of the extracted information as a single input into artificial neural networks; and determining the borehole holdup with the artificial neural networks.

Abstract: A system for drilling a wellbore into an earth formation includes a logging tool in the wellbore having at least one near-range measurement sensor, and a processor. The processor is configured to receive, at each depth along the wellbore, near-range measurement data and reference data related to a density of the formation, determine one or more near-range earth models that include a density model of a layer at each depth based on the near-range data constrained by the reference data, receive surface gravitational data from multiple surface locations, determine a mid-range or far-range formation model based on the near-range earth model and the surface gravitational data, and provide the mid-range or far-range formation model to a well driller for geosteering a drill bit into the earth formation.