Abstract: Systems and methods for drilling a wellbore include delivering electrical energy to a downhole end of the wellbore. A tapered drill string, with larger drill pipes connected in an up-hole portion with a turbine and an electrical generator and a smaller drill pipes coupled in downhole portion may be used to deliver the electrical power. A turbine and generator may be sufficiently sized to harvest the necessary hydraulic energy and safely operated in a subterranean environment. An electrode carried by the downhole portion of the drill string is electrically coupled to the generator through the downhole portion of the drill string.

Abstract: Methods and systems for controlling proppant concentration in a hydraulic fracturing slurry include measuring volumetric flow rates of fracturing fluid input to a blender and hydraulic fracturing slurry output from the blender, using these measured values to calculate a volumetric flow rate of proppant input, a slurry density and/or a slurry volume fraction, adjusting first and second valves to control rates of fluid and proppant delivery to the blender and re-measuring the volumetric flow rates and recalculating until target values of volumetric flow rate of proppant input, slurry density and/or slurry volume fraction are achieved.

Abstract: The present disclosure relates to downhole fluid additives including a clay, a hydroxylated polymer, a cation, and water. The disclosure further relates to downhole fluids, including drilling fluids, spaces, cements, and proppant delivery fluids containing such as downhole fluid additive and methods of using such fluids. The downhole fluid additive may have any of a variety of functions in the downhole fluid and may confer any of a variety of properties upon it, such as salt tolerance or desired viscosities even at high downhole temperatures.

Abstract: A system can receive data that can indicate a flow rate with respect to perforations in a reference wellbore. The data can be received from a fiber optic cable in the reference wellbore in a geographic area of interest. The system can determine a uniformity index, which can indicate a uniformity of flow with respect to the perforations, based on the data. The system can generate a pressure-based model by training a model using the uniformity index for applying the pressure-based model to a target wellbore in the geographic area of interest to determine controls to rate and proppant with respect to the target wellbore.

Abstract: Distributed artificial intelligence (AI) can be used to monitor a wellbore operation in some examples described herein. In one such example, physical equipment can be positioned at a surface of a wellsite to support a drilling operation at the wellsite. Each piece of physical equipment may include a sensor module, a processor communicatively coupled to the sensor module, and a memory. The memory can include an AI module configured to determine a condition associated with the equipment by analyzing sensor data from the sensor module using one or more machine-learning models. The memory additionally can include a warning module for causing the processor to output a warning notification based on the condition. The memory further can include a communications module for causing the processor to transmit a communication indicating the condition to a destination via a network. The communication may be different from the warning notification.

Abstract: Contamination estimation of a mud filtrate or reservoir sample requires a robust handle on the properties of mud filtrate at downhole conditions. Coupling acquired data with downhole measured data provides a robust estimation of contamination by encompassing the entire available data. Downhole density of the mud filtrate sample may be estimated based on a characteristic of the mud filtrate sample. A density of a formation fluid of the reservoir may be determined using a formation tester tool. The contamination of the formation fluid may be estimated based on the clean fluid density and the estimated mud filtrate density by, for example, using a material balance equation or ratio. An estimated pump-out time for the formation fluid may be determined based on the estimated contamination and a trend of the estimated contamination of the formation fluid.

Abstract: In some embodiments, a method includes generating at least a first pulse sub-sequence comprising a number of refocusing pulses at a first flip angle and generating at least a second pulse sub-sequence comprising a number of refocusing pulses at a second, lower flip angle. The method further includes detecting, by a nuclear magnetic resonance (NMR) sensor of a logging tool positioned in a wellbore formed in a subsurface formation, NMR spin-echo signals generated in response to at least the first pulse sub-sequence to acquire a first dataset of transversal NMR relaxation data, detecting, by the NMR sensor, NMR spin-echo signals generated in response to at least the second pulse sub-sequence to acquire a second dataset of transversal NMR relaxation data, and determining a property of the subsurface formation based on the first and second datasets of transversal NMR relaxation data.

Abstract: The disclosed embodiments include methods to monitor expansion of a metallic sealant deployed in a wellbore, methods to monitor downhole fluid displacement, and downhole metallic sealant measurement systems. The method to monitor expansion of a downhole metallic sealant includes deploying a metallic sealant deployed along a section of a wellbore. The method also includes exposing the metallic sealant to a reacting fluid to initiate a galvanic reaction. The method further includes measuring a change in temperature caused by the galvanic reaction. The method further includes determining an amount of expansion of the metallic sealant based on the change in the temperature.

Abstract: A downhole tool for use in a well comprising a mandrel and an outer sleeve slidably disposed about the mandrel. An inner sleeve is slidably disposed in the mandrel. A drive pin comprising a drive pin bushing connected to the outer sleeve and a shear pin connected to the inner sleeve connects the inner sleeve to the outer sleeve.

Abstract: Systems and methods for separating paramagnetic material in wellbore return fluid. A quadrupole magnet system is disposed along conduit so that a paramagnetic field is symmetrically formed about a central axis of the conduit. A wellbore return fluid containing paramagnetic material is directed through the conduit. The paramagnetic field drives the paramagnetic material outward towards the perimeter of the conduit, thereby concentrating fluid with little or no paramagnetic material along the central axis of the conduit. An outlet is disposed along the flow path of a portion of the concentrated fluid. In some embodiments, the outlet is positioned along the central axis, while in other embodiments, the outlet is positioned along the conduit wall. The paramagnetic material may be weighting material used to prepare drilling mud.

Abstract: A method and system for determining fluid contamination. The method may comprise monitoring a fluid sample, wherein the fluid sample comprises a reservoir fluid contaminated with a well fluid, and obtaining input parameters, wherein the input parameters comprise fluid properties obtained from measurement of the fluid sample and mud filtrate composition. The method may further comprise representing a mud composition as a Gaussian distribution, selecting a plurality of input data during a pumpout, determining calculated fluid properties of the reservoir fluid using an equation of state filtrate analysis, and further obtaining updated values of iterative parameters for use in a mole fraction distribution function.

Abstract: A system for generating a cement composition comprising: a plurality of cementitious components; and a computer system configured to accept input from a user and generate concentrations of the cementitious components for the cement composition, wherein the computer system is configured to generate the concentrations of the cementitious components based on a target lime to silica correlation.

Abstract: The present disclosure relates to a pulsed-power drilling system that includes downhole mixers for restoring optimal electrical properties in drilling fluid. The downhole mixer may include a housing having an uphole and downhole end, a channel to convey the drilling fluid through the housing, and a flow restrictor including an orifice having a fixed diameter positioned in the channel between the entrance and the exit of the channel to create a pressure drop between the entrance and the exit of the channel during a drilling operation. The pressure drop increases shear stress in the drilling fluid to manage electrical properties, such as a dielectric constant, of the drilling fluid. The electrical properties of the drilling fluid facilitate the formation of an electrical arc on a drill bit of the pulsed-power drilling system.

Abstract: A system for a wellbore can include a tubing string positioned downhole in a wellbore and a porous gravel pack. The porous gravel pack can be positioned in an annulus defined at least in part by a surface of the tubing string. The porous gravel pack can be made up of a plurality of grains. Each grain can include a core surrounded at least in part by a sheath. The core can comprise an expandable material that can expand in response to coming in contact with a fluid. The sheath can surround the core and can be deformable in response to the core expanding in response being exposed to a fluid.

Abstract: A measurement tool may be positioned downhole in a wellbore for measuring formation properties and drilling mud properties during a drilling operation. The measurement tool may include a body and an antenna. The body may include magnets for generating a magnetic field and a transmitter for transmitting a radiofrequency pulse. The antenna may be positioned proximate to the body to measure properties using nuclear magnetic resonant frequencies. The antenna may measure formation properties in a first volume of a formation using a first frequency. The antenna may measure drilling mud properties in a second volume in a borehole using a second frequency.

Abstract: Provided, in one aspect, is a downhole magnetic debris removal apparatus. The downhole magnetic debris removal apparatus, in one aspect, includes a housing having a longitudinal axis, and a plurality of magnets arranged as one or more Halbach arrays of magnets coupled to the housing, the one or more Halbach arrays of magnets having a strong side and a weak side.

Abstract: Methods for determining water-filled porosity using a general volumetric mixing law and the measurements of a dielectric tool are described. The water-filled porosity estimates are used to obtain water salinity estimates and the optimal parameters of the volumetric mixing law. These estimates are in turn used to generate novel quality indicators.

Abstract: Methods and compositions for performing a sealing operation in a wellbore. An example method introduces a sealant composition into the wellbore while the sealant composition is under shear. The sealant composition comprises a thixotropic material, a conformance gel system, and an aqueous base fluid. The sealant composition is placed into a target location, and applied shear is reduced to the sealant composition when in the target location thereby allowing the sealant composition to thicken in the target location. Fluid flow across the target location is reduced by a fluid seal formed by the thickened sealant composition.

Abstract: Disclosed herein are aspects of an expandable metal wellbore anchor for use in a wellbore. The expandable metal wellbore anchor, in one aspect, includes one or more expandable members positionable on a downhole conveyance member in a wellbore, wherein the one or more expandable members comprise a metal configured to expand in response to hydrolysis, and wherein a combined volume of the one or more expandable members is sufficient to expand to anchor one or more downhole tools within the wellbore in response to the hydrolysis.

Abstract: A float for use with a fluid flow control device. The float, in at least one aspect, includes a fluid impermeable exterior, and a base material having one or more cavities positioned within the fluid impermeable exterior, the base material formed using an additive manufacturing process.