Drilling Research Articles

Повышение стойкости зубьев буровых долот за счет изменения технологии их изготовления

Introduction. The development of the mining industry requires increasing the durability and safe tool performance life. For bits of mining drilling machines, this problem is often solved by improving the material of the teeth of these bits. The paper presents the results of a study on the development of a technology for the manufacture of hard-alloy drill bits with increased wear resistance and testing of prototypes when drilling hard rocks. Changes in technology have led to changes in the shape of the tooth. Also, purer tungsten powder was used as the initial component. Research methods. The paper studies carbide teeth of bits manufactured at JSC Almalyk Mining and Metallurgical Combine using standard and modified technology. Its structure and chemical composition were studied. Results and discussion. New methods for performing technological operations for the manufacture of carbide teeth (pins) and steel pin bits are developed and mastered. Tungsten-cobalt teeth were manufactured using VK10KS (90 %W; 10 % Co) hard alloy, produced using tungsten carbide powder synthesized by carbidization of purified tungsten powder. The shape of the tooth surface was changed from ballistic to semi-ballistic. Metallic cobalt powder was used as a binder. Pin bits of the KNSh40×25 type are made of 0.35 C-Cr-Mn-Si steel. Tests of experimental bits were carried out at several mines, as a result of which its suitability for drilling rocks with a hardness of f` = 14–18 was established. The results of industrial operation showed that the durability of the teeth of bits manufactured by JSC Almalyk Mining and Metallurgical Combine is not significantly inferior to bits from European manufacturers. At the same time, the cost of such bits is several times lower.

Smart tool wear state and chatter onset identification system for legacy manual drilling machine operators

Smart tool wear state and chatter onset identification system for legacy manual drilling machine operators

Adaptive Control of Constrained Nonlinear Systems With Intermittent Faults: A Fixed‐Time Fault‐Tolerant Framework Based on Projection Operator

ABSTRACTThis article investigates the problem of adaptive fixed‐time fault‐tolerant control for nonlinear systems with time‐varying intermittent faults and asymmetric output constraints. For this purpose, a novel adaptive law based on the projection operator technique is developed to estimate time‐varying intermittent faults, which eliminates the problem that the estimated value increases continuously with the accumulation of fault times. Considering that the fault estimation time needs to be less than the minimum time interval of intermittent faults, the fixed‐time design methodology is introduced to ensure that the relationship between the above two can be quantitatively analyzed. Then, a novel adaptive fixed‐time fault‐tolerant control strategy is put forward for the closed‐loop system, in which a universal barrier function is adopted to remain the system output in the time‐varying asymmetric constraint condition invariably. The theoretical analysis indicates that the developed strategy can guarantee the boundedness of all signals in the closed‐loop system in a fixed‐time. Finally, two examples, one of which involves the rotary steerable drilling tool systems are provided to demonstrate the feasibility and validity of the put forward scheme.

Feasibility of robotic posterior fossa skull base surgery

OBJECTIVE Despite its potential advantages, robotic surgery has yet to be applied to skull base procedures. Complex anatomy and restricted access have limited the development of robotic skull base surgery. The authors’ aim was to conduct a feasibility study of robotic surgery for posterior fossa skull base lesions. METHODS Six silicone-injected postmortem human heads were prepared for the robotic surgery. Because there was no drilling tool with the robot, specimens were dissected in advance using an endoscope and microscope. The following approaches were investigated: 1) supracerebellar-infratentorial; 2) retromastoid; and 3) posterior occipitocervical junction surgeries. For each approach specific anatomical landmarks were identified, and the surgical freedom (vertical distance angle between the tools) was measured. RESULTS In the case of the supracerebellar-infratentorial approach, the authors used 3 burrs with 1.5 cm of diameter: 1 paramedian and 2 laterally. The view of the pineal region was visualized, and sufficient surgical freedom of both tools was secured. The median vertical distance was 1.2 cm (range 1.1–1.8 cm), and the median angle between the tools was 105° (range 92°–110°). On the other hand, in the retromastoid approach, with a single burr 2.5 cm in diameter, the root exit zone of the facial nerve was barely visible, and a space for tools to access was not secured. The median vertical distance was 0.8 cm (range 0.6–1.0 cm), and the median angle between the tools was 10° (range 6°–12°). In the case of the posterior occipitocervical junction approach, the authors used the 3 tubular retractors, 1 in the middle and 2 laterally. Even though the space was narrow, the medulla and adjacent nerves could be identified, and a moderate level of surgical freedom could be obtained for tool mobilization. The median vertical distance was 1.6 cm (range 1.2–2.5 cm), and the median angle between the tools was 90° (range 88°–95°). CONCLUSIONS Although robotic surgery has yet to be applied to neurosurgery, it is expected to be helpful in posterior fossa skull base surgery if appropriate tools can be developed.

Technology Focus: Bits and Bottomhole Assemblies (December 2024)

Drillstring dynamics has been a central focus of research and mitigation efforts in the drilling industry for many years. The effect of dysfunction and poor dynamic motion extends far beyond simply reducing the lifespan of drilling equipment. When these issues degrade borehole quality to the extent that petrophysical measurements become compromised, managing these dynamics becomes crucial. Addressing drillstring dynamics in these cases effectively can be the key to improving our understanding of reservoir characterization, which directly affects hydrocarbon-recovery strategies. Neglecting to manage these dynamics thus not only risks immediate operational setbacks but also threatens to diminish overall hydrocarbon recovery. The integration of the latest state-of-the-art technology in modeling and measurement of drilling dynamics and borehole quality has enhanced the understanding of bit, bottomhole assembly (BHA), and drillstring design. This can be seen in recent work on analysis of cutter-formation interaction, borehole-quality improvement, and modeling improvements. This progress allows drilling teams to make more-informed, proactive adjustments to drilling parameters, thereby avoiding the negative consequences of dysfunction. As the drilling industry shifts its focus toward geothermal drilling, understanding and modeling drillstring dynamics takes on even greater importance. Geothermal drilling frequently encounters harder igneous and metamorphic rocks, which pose unique challenges. In these conditions, the performance of the drill bit, BHA, and drillstring becomes critical. Accurate modeling and effective management of these dynamics are essential to optimizing drilling efficiency and minimizing the risk of equipment loss or operational failures. In this context, ongoing research and innovation in both drillstring dynamics and its modeling are vital to the success of geothermal, hydrocarbon, and other drilling projects. Yet the best mitigation applied may not be the latest but existing tried and tested equipment. Recommended additional reading at OnePetro: www.onepetro.org. OTC 35320 Applications, Results, and Lessons Learned From Using Roller Reamers in Hard, Abrasive Formations—The FORGE Project Application by E. Almanza, Redback Drilling Tools, et al. SPE 217939 Avoiding High Local Doglegs by Integrating the Drill Bit Into the Rotary Steerable System by M. Hahn, Baker Hughes, et al. SPE 220789 Modeling PDC Cutter Loads When Drilling Interbedded Formations at Constant Penetration per Revolution vs. Weight on Bit by Paul E. Pastusek, Pastusek and Associates, et al.

A study on fatigue life evaluation of 42CrMo steel under cyclic loading based on metal magnetic memory method

Accidents involving drilling tool fractures in the process of oil and gas resource exploration and development occur frequently, and there are few detection methods for detecting the residual fatigue life of drilling tool joints with irregular surfaces. Therefore, developing a quick and effective method to evaluate fatigue damage in drilling tool joints is particularly important. In this study, a fatigue life evaluation method for ferromagnetic materials was established based on metal magnetic memory (MMM) detection technology, which can be used in the petroleum industry to evaluate the remaining life of drilling tool joints. First, the relationship between the impact load and specimen fatigue life was determined through a simulation, followed by a fatigue test, and the magnetic signals on the surface of the specimen under different fatigue loads were collected. The effects of the three evaluation methods were compared, and it was found that dynamic time warping (DTW) was more accurate for the evaluation of metal fatigue. Finally, a fatigue damage evaluation model for ferromagnetic metallic materials was established, and the feasibility of the method was verified using test data. This method can effectively predict the remaining fatigue life of threaded specimens, and can be applied in the petroleum industry to evaluate the remaining fatigue life of drilling tool joints. This study provides guidance for the petroleum industry in ensuring the safety of drilling tools.

Technology and equipment for pulling stuck drilling tool in horizontal directional drilling

Technology and equipment for pulling stuck drilling tool in horizontal directional drilling

Study on the Bearing Characteristics and the Influence of Pile Characteristics of Rotary Drilling Screw-Shaped Pile

Study on the Bearing Characteristics and the Influence of Pile Characteristics of Rotary Drilling Screw-Shaped Pile

Empirical relationship of characteristic impedance with rock drillability and cuttability

ABSTRACT In rock and mining engineering, it is essential to predict rock cuttability and drillability for estimating drilling costs, selecting suitable drilling/cutting machine and tools, and achieving high productivity. To predict the drillability and cuttability, many destructive methods have been developed. However, they are often expensive and time-consuming. To explore a non-destructive method, this paper builds a series of empirical relationships between rock characteristic impedance and its drillability and cuttability indices by using a large quantity of measured data from various laboratory and field tests in previous publications. The relationships between rock’s UCS (uniaxial compressive strength) and its drillability and cuttability indices are also built for comparison. The results indicate that: (1) the penetration rates of both percussive drilling and rotary drilling depend on rock characteristic impedance, and they decrease with increasing impedance. (2) The specific energies in percussive drilling, rotary drilling and cutting all increase with increasing rock impedance. (3) Most of current drillability indices such as alfa, DRI, CLI and Shore hardness have a certain relationship with rock impedance. (4) Characteristic impedance has a more confident relation with drillability and cuttability than the UCS. Since determination of rock impedance does not necessarily require a destructive method, characteristic impedance has a great potential to be taken as an index to predict rock drillability and cuttability.

Development and Application of a Rope Core Hydraulic Closed-Core Mechanism for Loose and Broken Strata

When employing the wire-line core drilling technology in loose strata, the core recovery rate is often low due to fragmented rock masses and the erosive effect of flushing fluids, severely affecting core quality and drilling efficiency. To address this, the paper designs a hydraulic closed-core cutting mechanism and water-sealed protective core bit compatible with traditional S75 wire-line core drilling tools. Comprehensive analysis and optimization of the design mechanism’s force, flow field patterns, and operational mechanisms have been conducted through numerical simulations, laboratory tests, and field applications. Studies indicate (1) the hydraulic cutting mechanism can smoothly close under flushing fluid action, with stress and strain within safe limits and the sealing area of the core barrel exceeding 75%; (2) post-optimization, the vortex flow within the flushing fluid flow control valve is significantly reduced, with the flow rate at the core after passing through the water-sealed protective core bit being less than 0.6 m/s, effectively protecting the core from being eroded by flushing fluids; (3) the hydraulic cutting mechanism has proven feasible through laboratory testing, with a recommended standard core claw with a 95% protective rate. In actual loose strata, the average core recovery rate reached 97.83%, an 88.13% increase compared to traditional drilling tools, demonstrating high engineering promotion value.

Microscopic Analysis and Evaluation of Thermal Elevation and Wear of Drills for Implant Site Preparation: An In Vitro Study.

Drilling for implant site preparation generates heat, which can cause bone necrosis if temperatures exceed 47 °C for over a minute. Factors influencing heat include drill size, speed, pressure, irrigation, and tool wear. Frequent drill replacement is essential, as wear from repeated use and sterilization affects performance. This study compared three pilot drills with similar designs from different manufacturers, testing each on pig ribs for 15 perforations after 15 sterilization cycles. Researchers measured temperature increase, drilling time, and surface wear. Results showed that drill no. 1 generated more heat than drills no. 2 and no. 3, though none reached critical temperatures. Drill no. 2 took the longest to reach the desired depth and displayed the most deformation. Findings highlight the importance of adhering to the recommended operational limits, suggesting that drills should be replaced after 15 cycles to ensure efficacy and patient safety.

Geoscience spillover: Gunnar Böðvarsson and the adoption of petroleum technologies in Iceland’s geothermal industry, 1940s–1970s

ABSTRACT During the twentieth century, Iceland became a leader in geothermal energy use, with hot water and steam providing for the heating of 9 out of 10 houses and almost one-third of the electricity supply. A crucial factor in the expansion of geothermal energy between the 1940s and 1970s were indirect ‘spillovers’ from the oil industry via the applied geosciences. While fundamentally different in end use, geothermal and hydrocarbon industries employ similar geoscientific methods for exploring and extracting fluids and gases. This article traces the spillovers from oil to geothermal by examining Iceland’s Geothermal Division and its founding director, Gunnar Böðvarsson. He saw the oil industry as a model and embraced its geoscientific exploration methods, oilwell rotary drilling and petroleum reservoir engineering. Adapted to the requirements of geothermal energy, petroleum technologies greatly improved the knowledge of geothermal reservoirs and the efficiency of well drilling and hot water and steam extraction. The geoscience spillover between oil and geothermal reveals an understudied dimension of geothermal history and the crucial role of the geosciences at the intersection of academia and energy industries, which also resulted in reverse spillovers from geothermal to oil and complicates the common dichotomization of fossil fuels vs. renewable alternatives.

Optimization of Rotary Drilling Rig Mast Structure Based on Multi-Dimensional Improved Salp Swarm Algorithm

The mast is a critical component of rotary drilling rigs, which has a cross-section consisting of a rectangular shape formed by two web plates and two flange plates. Structural optimization of the mast is necessary to address the issue of excessive weight. The shortcomings of the traditional structural optimization algorithms are summarized as follows: the optimized steel plate thickness is a non-integer, where rounding upwards may increase the cost to a certain extent, but it can ensure the safety of the structure; rounding downwards its load carrying capacity may not satisfy the requirements, and thus a novel Salp Swarm Algorithm is proposed to solve the optimization problem. First, this study improves the initialization and update strategy in the traditional Salp Swarm Algorithm. In order to obtain a solution for engineering, an innovative multi-dimensional running comparison is carried out. Secondly, the optimization model of rotary drilling rigs is established based on the division of the working conditions. The objective function of the optimization model is to minimize the weight of the mast while considering the constraints of strength, stiffness, stability, and welding process. Finally, the proposed optimization algorithm and the established optimization model are applied to optimize the design of the mast for a rotary drilling rig. The empirical results demonstrate that the weight of the mast has been reduced by 20%. In addition, the Improved Salp Swarm Algorithm exhibits higher solution quality, faster iteration capability, and extreme stability in optimizing welded box sections compared to the conventional algorithm. The example shows that the Improved Salp Swarm Algorithm is applicable to the optimization problem of box sections.

A supervised machine learning model to select a cost-effective directional drilling tool

With the increased directional drilling activities in the oil and gas industry, combined with the digital revolution amongst all industry aspects, the need became high to optimize all planning and operational drilling activities. One important step in planning a directional well is to select a directional tool that can deliver the well in a cost-effective manner. Rotary steerable systems (RSS) and positive displacement mud motors (PDM) are the two widely used tools, each with distinct advantages: RSS excels in hole cleaning, sticking avoidance and hole quality in general, while PDM offers versatility and lower operating costs. This paper presents a series of machine learning (ML) models to automate the selection of the optimal directional tool based on offset well data. By processing lithology, directional, drilling performance, tripping and casing running data, the model predicts section time and cost for upcoming wells. Historical data from offset wells were split into training and testing sets and different ML algorithms were tested to choose the most accurate one. The XGBoost algorithm provided the most accurate predictions during testing, outperforming other algorithms. The beauty of the model is that it successfully accounted for variations in formation thicknesses and drilling environment and adjusts tool recommendations accordingly. Results show that no universal rule favors either RSS or PDM; rather, tool selection is highly dependent on well-specific factors. This data-driven approach reduces human bias, enhances decision-making, and could significantly lower field development costs, particularly in aggressive drilling campaigns.

Research on Influence Laws of Vibration by Rotary Drilling During Foundation Excavation on Surrounding Buildings and the Environment

Research on Influence Laws of Vibration by Rotary Drilling During Foundation Excavation on Surrounding Buildings and the Environment

Optimal configuration design and attitude measurement method of redundant accelerometer for steering drilling tools

Abstract In order to improve the accuracy and reliability of attitude parameters measurement of the rotary steerable drilling tool, a slanting configuration method and measurement method of double accelerometer were proposed. The measurement equation of the redundant accelerometer in the drill coordinate system is established. According to the installation position of the accelerometer and sensitive direction, the trouble-free and uniaxial failure in both cases, in order to improve the component of gravity and angular velocity calculation precision as the objective, design measure performance evaluation indexes, the optimal configuration determines the redundant accelerometer. It uses the stability equation constraints gravity no trace adaptive Kalman filter algorithm, Accurate angular velocity measurement, the tool face Angle, and healthy inclination. Simulation and experimental results show that the optimal configuration of the redundant accelerometer is reasonable, and the attitude estimation algorithm is effective.

Accurate determination of drilling parameters in time series for estimate of rock strengths

Geotechnical engineering usually produces drillholes in the ground for investigation and construction. Drilling is a rock-breaking process by applying normal (thrust) and shear (torque) force from the drill bit to the rock below the bit. These rock-breaking data can be obtained by digital monitoring and recording the drilling parameters through an instrumented drilling machine. However, there is no mature and standard method to determine rock strength properties (such as unconfined compressive strength, UCS, or tensile strength) from real-time monitored drilling parameter (such as thrust force, torque, rotation speed, drilling speed and specific energy). This paper presents a complete procedure to accurately determine each drilling parameter. More importantly, the specific energy develops nonlinearly with change of the thrust force, which is related to the UCS and tensile strength of the rock. This finding provides an insight into determining the UCS and tensile strength of the rock based on real-time monitored drilling parameters. In addition, novel test setups are demonstrated to determine the thrust force and torque from hydraulics pressures and rotation speeds. These setups can significantly reduce the sophisticated instrumentation cost for drilling monitoring studies. Three type rocks including granite, limestone and sandstone are used for the testing. The findings from this study provide supporting theories to upgrade drilling monitoring technique to a standard geotechnical testing method.

Dynamics modeling and analysis of a down-hole drill string multibody system based on the absolute coordinate formulation

Abstract Drilling system dynamics is the basis of studying the interaction between components in drilling process, which needs to solve many difficult problems such as geometric nonlinear dynamics of drill string, contact between drill string and wellbore, solving timeliness and so on. The existing research on establishing dynamic unit of local drilling tool structure has low solution efficiency, and it is difficult to meet the requirements of directional trajectory control and drilling speed increase analysis efficiently. Dynamics model of a downhole drill string system is established by using the multibody system dynamics method in this study. The natural coordinate formulation and the absolute nodal coordinate formulation are adopted to describe the rigid parts and the flexible beams, respectively. The presented model can be used to analyze the dynamic characteristics of the drill string system and the interaction between the drill string and the environment such as the wellbore and rocks in the drilling process. Finally, through comparative analysis with on-site test data, the correctness of the multibody dynamic model of the drill string system established in this paper was preliminarily verified.

Co-Designing Dynamic Mixed Reality Drill Positioning Widgets: A Collaborative Approach with Dentists in a Realistic Setup.

Mixed Reality (MR) is proven in the literature to support precise spatial dental drill positioning by superimposing 3D widgets. Despite this, the related knowledge about widget's visual design and interactive user feedback is still limited. Therefore, this study is contributed to by co-designed MR drill tool positioning widgets with two expert dentists and three MR experts. The results of co-design are two static widgets (SWs): a simple entry point, a target axis, and two dynamic widgets (DWs), variants of dynamic error visualization with and without a target axis (DWTA and DWEP). We evaluated the co-designed widgets in a virtual reality simulation supported by a realistic setup with a tracked phantom patient, a virtual magnifying loupe, and a dentist's foot pedal. The user study involved 35 dentists with various backgrounds and years of experience. The findings demonstrated significant results; DWs outperform SWs in positional and rotational precision, especially with younger generations and subjects with gaming experiences. The user preference remains for DWs (19) instead of SWs (16). However, findings indicated that the precision positively correlates with the time trade-off. The post-experience questionnaire (NASA-TLX) showed that DWs increase mental and physical demand, effort, and frustration more than SWs. Comparisons between DWEP and DWTA show that the DW's complexity level influences time, physical and mental demands. The DWs are extensible to diverse medical and industrial scenarios that demand precision.

An improved method to extract the vibration frequency of torsional impactor

Abstract The torsional impactor can convert the kinetic energy of drilling fluid into high-frequency circumferential kinetic energy and provide it to the bottom drilling tools, thereby eliminating stick-slip vibration, protecting Polycrystalline Diamond Compact (PDC) bit and improving construction efficiency. As the test can not be directly performed and the working conditions of torsional impactor can not be quantified by using existing sensors due to the narrow space structure of the impactor and complex vibration conditions, a method for measuring the operating frequency of torsional impactor was designed based on the adaptive white noise complete set empirical mode decomposition of surface acceleration signal data and wavelet threshold denoising. In this paper, the data processing algorithm is used to implement and carry out the simulation test experiments, and the experimental results show that the method can accurately measure the vibration frequency of the torsional impactor under simulated working conditions, and effectively quantify its working state.