Abstract: Based on measurements of forces and rotational velocity experienced by a drill bit during drilling, drilling behavior is detected and identified. Measurements of forces on a drill bit including torque on bit (TOB), weight on bit (WOB), etc. and measurements of rotational velocity (rotations per minute or RPM) are acquired in real time at the drill bit. Various measurements are correlated to produce related combinations of measurements, such as WOB-RPM, TOB-RPM, and RPM-time. Based on fitting between the combinations of measurements and curves corresponding to predetermined torsional behavior trends, torsional, axial, and rotational behaviors are classified as functional or dysfunctional.

Abstract: Methods for simulating a downhole drilling operation include estimating the geometry, i.e., the shape, size of rock chips generated by engagement of a drill bit with a geologic formation. Each cutting element on the drill bit may produce rock chips of different geometry, and the geometry of rock chips generated by a particular cutting element may change over a predetermined interval. The geometry and other properties rock chips predicted for an interval may be recorded, and a distribution may be calculated based on categorizing each of the predicted rock chips into predefined categories and determining the relative number of rock chips in each category. The distribution may be useful in drill bit design, determining required mud flow characteristics for a drilling operation, and facilitating rotation of a drill string by preventing undesirable interactions of the rock chips with the drill bit and other downhole equipment.

Abstract: Disclosed are an oxazoline compound, a synthesis method therefor and an application thereof. The oxazoline compound has a structure represented by formula (I), wherein in the formula (I), R is selected from groups represented by formula (I-1), formula (I-2), and formula (I-3), where an oxazoline derivative having a novel molecular structure is obtained by introducing a nitrogen heterocycle, an ether bond or a sulfonate structure into the oxazoline compound. The oxazoline derivative is useful in the field of agricultural protection, and has higher acaricidal activity than etoxazole, can inhibit the synthesis of chitin from mites, and can effectively control the embryogenesis and development of eggs of Tetranychus cinnabarinus, as well as the ecdysis process from larvae to adults, and therefore has a significant effect in killing mite eggs and larvae.

Abstract: Design parameters for PDC drill bit are correlated to instances of backward whirl, where backward whirl is detected along a lateral axis in the frequency domain during downhole drilling. Two regimes of backward whirl are described and detected cutting-induced backward whirl and friction-induced backward whirl where each regime has different characteristic frequencies, detection methods, and mitigation guidelines. Design parameters are quantified by gauge fullness, drilling efficiency (DE), and whirl index (WI). Design guidelines to mitigate backward whirl are generated by correlating design parameter quantifiers and instances of backward whirl, including both cutting-induced backward whirl and friction-induced backward whirl. Potential drill bit designs are then validated against the generated guidelines in order to mitigate backward whirl in future drilling runs.

Abstract: This disclosure relates to a sensor that detects bacteria cells comprising (a) a primary negatively charged, nanoparticulate sensing material; (b) a secondary positively charged, fluorescent sensing material; (c) a housing; and (d) at least one illuminator. This disclosure further relates to a method for detecting bacteria cells.

Abstract: A vibrational disfunction machine learning model trainer trains a vibrational disfunction classifier to identify one or more types of vibrational disfunction, or normal drilling, based on measurements of at least one of displacement, velocity, acceleration, angular displacement, angular velocity, and angular acceleration acquired for the drill bit. The vibrational disfunction machine learning model trainer trains the algorithm based on data sets corresponding to characteristic behavior for one or more types of vibrational disfunction and normal drilling. The vibrational disfunction classifier operates in real time, and can operate at the drill bit and communicate vibrational disfunction identification in real time, allowing mitigation of vibrational disfunction through adjustment of drilling parameters.

Abstract: A method of designing a drill bit is disclosed. The method includes determining a location of a bit coordinate system in a wellbore coordinate system and generating a bit profile based on an angular coordinate around a wellbore axis of a wellbore and the location of the bit coordinate system. The bit profile is based on a cutting edge of a first cutting element on an exterior portion of a first blade. The method also includes determining a cutting layer volume based on the bit profile and identifying a weak zone based on the cutting layer volume being less than a predefined minimum cutting layer volume. The method includes determining a location for a second cutting element on the exterior portion of a second blade based on the weak zone.

Abstract: A drill bit includes a bit body defining a rotational axis, a plurality of blades on the bit body, a plurality of cutting elements on the plurality of blades, each cutting element defining a sweep profile about the rotational axis, a first depth of cut controller (DOCC) movably secured to one of the plurality of blades and movable in response to contact by a formation when drilling, and a second DOCC movably secured to the one of the plurality of blades, the second DOCC coupled to the first DOCC such that movement of the first DOCC changes a height of the second DOCC relative to a height of the first DOCC.

Abstract: A method for developing design rules for mitigating cutting-induced stick-slip vibration includes determining at least one value for one or more drill bit performance parameters for a design of a drill bit. The one or more drill bit performance parameters include a functional characteristic of a depth of cut controller of the drill bit. The method includes correlating one or more instances of cutting-induced stick-slip vibration for at least one prior drilling operation to the at least one value for the one or more drill bit performance parameters. The method includes generating drill bit design rules that mitigate cutting-induced stick-slip vibration based on the correlating.

Abstract: Design parameters for PDC drill bit including in-cone depth of cut controllers (DOCCs) are correlated to instances of coupled vibrations in the axial, lateral, and torsional directions occurring during downhole drilling. Design parameters are quantified by drilling efficiency (DE), average in-cone DOCC contact area, average weight on bit (WOB) taken off by in-cone DOCC, and average torque on bit (TOB) taken off by in-cone DOCC. Design guidelines to mitigate coupled vibrations are generated by correlating design parameter quantifiers and instances of coupled vibrations. Potential drill bit designs are then validated against the generated guidelines in order to mitigate vibration in future drilling runs.

Abstract: A device includes a drill bit body defining an axis of rotation, a plurality of drill blades on the drill bit body, and a shaped cutter secured to at least one of the plurality of drill blades. The shaped cutter including an engagement surface having an exposed partially flattened boundary, wherein a contact point of the engagement surface during drilling is off-centered with respect to a center of the exposed partially flattened boundary.

Abstract: Drill bit vibration data for lateral, axial, and torsional directions of a drill bit is collected for a simulated or deployed drill bit for visualization of 3D coupled vibration. A frequency converter transforms the drill bit vibration data into frequency vibration data. A drill bit analyzer identifies local maxima (“peaks”) in the frequency vibration data in each of the lateral, axial, and torsional directions. Common peaks across all 3 directions with sufficiently high frequency and sufficiently high bit rotation speed are indicated as 3D coupled vibration. A drill bit data visualizer uses the indications of 3D coupled vibration in addition to the vibration data and frequency vibration data to generate visualizations of 3D coupled vibration in the drill bit.

Abstract: A drill bit design generator uses drill bit metrics to generate drill bit designs with reduced 3D coupled vibration. The drill bit design generator generates an initial set of drill bit designs that are simulated in a deployed or artificial environment. Simulated drill bits according to the initial drill bit designs have gyroscopic sensors that detect the presence of 3D coupled vibration. A drill bit simulator tracks metrics such as side cutting efficiency and drilling efficiency during simulations and correlates these metrics with 3D coupled vibration. The drill bit design generator determines thresholds for these metrics using correlations with 3D coupled vibration and generates updated/new drill bit designs using the metric thresholds.

Abstract: An apparatus includes a processor and a machine-readable medium having program code executable by the processor to cause the apparatus to determine a first parameter based on a walk force of a drill bit. The program code also includes instructions to generate a whirl index value that comprises a ratio of drilling parameters, wherein at least one parameter of the ratio of drilling parameters is the first parameter. Based on a determination that the whirl index value exceeds a whirl index threshold, the program code includes instructions to determine that a drilling operation induces backward whirl, wherein the drilling operation is characterized by the drilling parameters.

Abstract: A multi-layer downhole drilling tool designed for drilling a wellbore including a plurality of formations is disclosed, including a bit body; blades disposed on exterior portions of the bit body; first layer cutting elements disposed on the exterior portions of the blades, the first layer cutting elements extending a first distance along a first direction and a second distance along a second direction, the first direction orthogonal to the second direction, wherein the first distance is less than the second distance; and second layer cutting elements disposed on the exterior portions of the blades, at least one of the second layer cutting elements track set with one first layer cutting element and the second layer cutting elements extending a third distance along the first direction and a fourth distance along the second direction, the third distance is greater than or equal to the first distance.

Abstract: This disclosure presents systems to enable downhole bi-directional communications using a long length of electrical cable located within or partially within the internal diameter of a set of lower pipe segments and communicatively coupled to one or more upper pipe segments that utilize pipe cable attached to the outside diameter of each of the upper pipe segments. The long length of electrical cable and the one or more pipe cables from the upper pipe segments allow for communication coupling between downhole tools and surface equipment and surface computing systems. In some aspects, the pipe cable attached to the upper pipe segments can be protected from wear using clamps, collars, cages, and other protectors. In some aspects, an electrical signal generator and modulator can be located downhole proximate the downhole tools, uphole proximate one of the upper pipe segments, or proximate the surface equipment.

Abstract: This disclosure presents systems to enable downhole bi-directional communications using a long length of fiber optic cable located within or partially within the internal diameter of a set of lower pipe segments and communicatively coupled to one or more upper pipe segments that utilize pipe cable attached to the outside diameter of each of the upper pipe segments. The long length of fiber optic cable and the one or more pipe cables from the upper pipe segments allow for communication coupling between downhole tools and surface equipment and surface computing systems. In some aspects, the pipe cable attached to the upper pipe segments can be protected from wear using clamps, collars, cages, and other protectors. In some aspects, an optical signal generator and modulator, e.g., a light source, can be located downhole proximate the downhole tools, uphole proximate one of the upper pipe segments, or proximate the surface equipment.

Abstract: The present disclosure relates to fixed-cutter drill bits with track-set primary cutters and backup cutters, methods of designing such bits, systems for implementing such methods, and systems for using such fixed-cutter drill bits to drill a wellbore in a geological formation.

Abstract: A drill bit includes a bit body defining a rotational axis, a plurality of blades on the bit body, a plurality of cutting elements on the plurality of blades, each cutting element defining a sweep profile about the rotational axis, a first depth of cut controller (DOCC) movably secured to one of the plurality of blades and movable in response to contact by a formation when drilling, and a second DOCC movably secured to the one of the plurality of blades, the second DOCC coupled to the first DOCC such that movement of the first DOCC changes a height of the second DOCC relative to a height of the first DOCC.