Drilling Research Articles

Design and Optimization of Direct-Drive Drilling Permanent Magnet Synchronous Motor

Abstract A direct-drive drilling electric drilling tool is developed due to the problems of long transmission link, low efficiency, and high failure rate of traditional electric drilling tools. In this paper, the key components of the direct-drive drilling permanent magnet synchronous motor (DPMSM) are designed and calculated, and the robust parameters optimization is performed by Taguchi method with efficiency and cogging torque as the optimization objectives. The air-gap length, thickness of permanent magnets, pole-arc coefficient, and width of slot top are selected as significant factors, and the impact of the optimized parameters on the efficiency and cogging torque of the DPMSM is calculated with orthogonal experiment to obtain the optimal combination of factors. Comparing the DPMSM’s performance before and after optimization, the cogging torque is reduced by 80.1% and the efficiency is improved by 0.24% after optimization. Finite element simulation of the electromagnetic characteristics of the optimized DPMSM under no-load and load conditions is carried out to verify the rationality of the optimization. Calculate the main losses of the DPMSM and the heat generation rate of key components. The analysis model of the DPMSM’s temperature field is established, and the temperature field simulation is carried out with and without drilling fluid respectively to further verify the rationality of the motor’s design. This work can promote the engineering application of downhole direct-drive electric drilling tools and provide technical support for the innovation of drilling equipments for marine energy.

Drillability Evaluation and Sensitivity Analysis of the Fencheng Formation Strata in Maye Exploration Area

Abstract Predicting drillability ratings and selecting suitable drill bits are crucial for improving drilling efficiency. This investigation employed Principal Component Analysis (PCA) to normalize adjacent well logging parameters such as natural gamma, well diameter, natural potential, and others as influencing factors and established a mathematical model for the drillability ratings of hard rock formations. A sensitivity analysis of drilling parameters for the Fencheng Formation rocks revealed that sonic time difference, formation density, natural gamma, and resistivity were closely associated with drillability ratings. Empirical results showed that a multiple logarithmic linear regression approach accurately predicted drillability ratings for hard rock formations with over 95% precision compared to experimental values. The Fencheng Formation strata’s high hardness and abrasion resistance result in poor drillability (with ratings above 7.5), with rotational speed sensitivity found to be higher than drilling pressure sensitivity for expediting drilling in hard formations. For the “turbine + PDC bit” drill tool combination, it is recommended to use a drilling pressure of 40 - 80KN and a rotary table speed of 50 - 70r/min. High rotational speeds and low drilling pressures effectively reduce bit sticking effects, while using PDC bits with turbines reduces bit wear, improving the economic efficiency of drilling operations without sacrificing mechanical drilling speed.

Fabrication and Performance Analysis of an Arduino-based Mini CNC Machine with Drilling and Engraving Tool

Abstract: The present work focuses on fabrication of a low cost numerically controlled machine with easily available materials and devices. The machine has been primarily fabricated to carry out a few low duty mechanical applications in a short period of time as well as at a minimal cost. Engraving tool of diameter mm and drill bit of diameter mm are used in our operations. Foam, Plywood, Aluminium sheet and Wood have been used as work-piece material. Study has been carried out to observe performance analysis on the above work-piece materials. Mathematical analysis has been done for different operating parameters like cutting speed, feed, depth of cut, machining time and MRR (Material removal rate) . It has been observed that for low duty applications, small size numerically controlled machines are more effective as well as advantageous compared to conventional large size cutting machines.

Dynamic analysis and experimental study of Down-the-Hole hammer based on DEM-MBD method

Pneumatic DTH(Down-The-Hole) hammer impact-rotary-compaction drilling is a well-established technology widely used in foundation engineering. This technique combines the advantages of impact rotary drilling and compaction drilling, making its working mechanism and fracturing process more complex. First, the dynamic differential equations for the DTH hammer piston and the coupled longitudinal vibration partial differential control equations for the DTH hammer and the soil stratum were established. The dynamic working characteristic curve of the piston was then obtained using the finite difference method(FDM).Subsequently, the DEM-MBD method was employed to compare the drilling efficiency of three types of drill bits—single-helix, multi-helix, and stepped bits—across three diameter specifications (Φ108, Φ135, Φ216) in three distinct strata: clay, pebble, and silty sand. The drilling efficiency of the multi-spiral bit was on average 11% and 21% higher than that of the single-spiral and stepped bits. From a micromechanical perspective, the shear failure effect of the drill bit on the soil was analyzed. The axial force of the drill bit (Z-axis) remained essentially consistent. Using the Y-axis as an example, 6% of the shear force for the single-helix bit falls within the 300–500N range, while 31% of the shear force for the multi-helix bit lies within the same range. Field tests demonstrated that the drilling efficiency and penetration effects simulated using the DEM-MBD method aligned with the actual test results, confirming the accuracy of this method.

New insights on impact wear of polycrystalline diamond compact: Effect of interface state on kinetic response and damage behavior

The impact wear of polycrystalline diamond compact (PDC) cutters caused by the discontinuous cutting during the drilling process significantly affects the lifespan and efficiency of the drilling tools. Different PDC impact contact interface states are realized through the selection of impact mating materials. Understanding the effects of different interface states on the kinetic response, damage behavior and impact wear mechanism of PDC is significant in guiding the practical design of material structures with excellent impact wear resistance. Therefore, the kinetic response and damage behavior of PDC impact with different mating materials are investigated. The results show that the kinetic response and damage behavior of PDC are correlated with the mechanical properties of the mating material and physicochemical changes at the impact surface interface. Adhesion and filling resulting from strong covalent bonding and filling effects mitigate the interfacial stress and reduce the average impact force of SiC and Al2O3. Moreover, brittle fracture and filling effects increase the consumption of kinetic energy of SiO2, resulting in an energy absorption of up to 86 %. In addition, the strong covalent bonding effects exacerbated the damage to the PDC interfaces, leading to the internal fracture of diamond particles and detachment at grain boundaries. Furthermore, the filling effect formed plays a specific protective role for diamonds. However, it increases the energy absorption rate and reduces the mating material damage efficiency. In this work, the relationship between impact interface state and impact wear mechanism has been established by understanding the kinetic response, damage morphology, and structural evolution.

Study on the Equivalent Density Tool and Depressurisation Mechanism of Suction-Type Depressurisation Cycle

In order to further regulate equivalent circulating density (ECD), a novel downhole apparatus for reducing circulating pressure in high-temperature and high-pressure wells, the suction-type ECD reduction tool, was devised. The utilisation of this tool enables the bottomhole pressure of the equivalent circulating density to be attained in close proximity to its hydrostatic pressure, thereby facilitating the attainment of deeper drilling depths. The tool is composed primarily of a screw motor, scroll blades, annular seals, universal joints, and drilling columns. The tool operates by utilising the suction effect and hydraulic energy extracted from the circulating fluid by the screw motor, which is then converted into mechanical energy to create suction and enhance the flow energy of the drilling fluid within the annulus at the bottom of the well, thereby reducing the equivalent circulating density. Furthermore, based on ANSYS-FLUENT analysis simulations, the alteration of pressure drop characteristics in response to varying drilling fluid densities, displacements, and tool sizes was modelled. The simulation results demonstrate that the pressure drop effect is 1.0 MPa when the drilling fluid density is 1.2 g/cm3, 1.7 MPa when the drilling fluid density is 1.5 g/cm3, and 1.9 MPa when the drilling fluid density is 1.8 g/cm3. A pressure drop of approximately 2.3 MPa was observed when the drilling fluid density was 2.0 g/cm3. The maximum pressure drop is achievable with a flow rate ranging from 1500 to 2500 L/min. A maximum pressure drop of 2.3 MPa is observed when the flow rate is within the range of 1500 to 2500 L/min. Two distinct viscosity values (0.02 and 0.06 kg/(m·s)) were employed to assess the impact of viscosity on pressure drop characteristics in a suction-type ECD tool. The results demonstrated that the pressure drop remained largely unaltered, indicating that viscosity had minimal influence on this parameter. The flow rate emerged as the primary factor affecting pressure drop, with viscosity exerting a relatively minor effect.

Polynomial filter-based adaptive fault-tolerant control for a class of nonlinear systems with multiplicative faults

In this article, the problem of fault-tolerant control is investigated for polynomial nonlinear systems (PNSs) subject to multiplicative faults and measurement noise. Firstly, a matrix Taylor expansion technique is applied to transform the PNS into a linear parameter varying system. Then the polynomial filter is constructed to get estimations of states and unmatched disturbances, which reduces the effect of measurement noise. A novel adaptive fault-tolerant controller is proposed to compensate for multiplicative faults and unmatched disturbances. Furthermore, the condition of the parameter-dependent linear matrix inequality (PDLMI) is deduced, which guarantees the boundedness of tracking errors and estimation errors, and the sum of squares (SOS) decomposition technique is utilized to solve PDLMI. Finally, the simulation of a rotary steerable drilling tool system confirms the feasibility of the proposed adaptive fault-tolerant control framework.

Thermal Evaluation of Bone Drilling: Assessing Drill Bits and Sequential Drilling.

Sequential drilling is a common practice in dental implant surgery aimed at minimizing thermal damage to bone. This study evaluates the thermal effects of sequential drilling and assesses modifications to drilling protocols to manage heat generation. We utilized a custom drill press and artificial bone models to test five drill bits under various protocols, including sequential drilling with different loads, spindle speeds, and peck drilling. Infrared thermography recorded temperature changes during the drilling process, with temperatures monitored at various depths around the osteotomy. The results reveal sequential drilling does not eliminate the thermal damage zone it creates (well over 70 °C). It creates harmful heat to surrounding bone that can spread up to 10 mm from the osteotomy. The first drill used in sequential drilling produces the highest temperatures (over 100 °C), and subsequent drill bits cannot remove the thermal trauma incurred; rather, they add to it. Modifying drill bit design and employing proper drilling techniques, such as reducing drilling RPM and load, can reduce thermal trauma by reducing friction. Inadequate management of heat can lead to prolonged recovery, increased patient discomfort, and potential long-term complications such as impaired bone-to-implant integration and chronic conditions like peri-implantitis. Ensuring healthy bone conditions is critical for successful implant outcomes.

Deep learning-based temperature prediction during rotary ultrasonic bone drilling

Bone drilling is a common but critical medical procedure in orthopedic surgeries used to treat fractured bones. During this procedure, the temperature of the bone increases due to generation of frictional energy. Temperature control has been a major challenge in bone drilling since its foundation. If this temperature increases over 47°C for 1 min, then it can result in permanent bone damage. To control the temperature elevation this study proposes a deep learning-based robust predictive model which has been trained and tested on data from pig bones. Excessive in-house testing has been done on pig femur bones to gather data and verify the results. Rotary ultrasonic bone drilling was the machining process used for drilling. Four independent variables which were rotational speed, feed rate, abrasive grit size, and vibrational ultrasonic power were varied and the temperature for each set of values was recorded. Multiple deep learning models were made and were compared on different error metrics. It was found that convolutional neural network 1D gave the least error over other models. The error generated by deep learning models was less than mathematical and experimental models.

Influence of HSS drill coatings on surface finish and cylindricity of AA6061/C/ZrO2 composite in CNC drilling operations under dry conditions

Abstract This study aims to evaluate the effect of HSS drill tool coatings, namely single-layer TiN, single-layer AlCrN, and double-layer AlTiN + TiSiXN (Durana), on the surface roughness and cylindricity of AA6061 (90 wt%)/C (5 wt%)/ZrO2 (5 wt%) hybrid composite material processed by the stir casting method. The fabricated sample was examined for the uniform particle distribution of reinforcements using Scanning Electron Microscope. The drilling operation was carried out on the fabricated in a CNC machining center by setting the spindle speeds of 800, 1200, and 1600 rpm, depths of cut of 0.5, 1, and 1.5 mm, and feeds of 50, 100, and 150 mm/rev. An orthogonal array (L27) designed by Taguchi’s method was used as the design of the experiment for the optimization of the best cutting parameters and coating. Surface roughness and cylindricity errors were determined for the 27 experimental runs. Field emission scanning electron microscopic (FESEM) examination and Energy Dispersive Spectroscopy (EDS) were used to analyze the surface integrity and elemental composition, respectively. The results revealed that Durana had a significant effect on the surface substrate with minimum surface roughness (Ra) of 1.666 μm and obtained the minimum cylindricity error for the parameters of depth of cut 0.5 mm, spindle speed of 1200 and feed of 100 mm rev−1.

Outer spiral drill rod lunar soil sampling resistance moment simulation study

Abstract The task of unmanned automated sampling of China’s lunar exploration is to bring back lunar soil samples with a certain depth, and sampling of external auger drill pipe is the best way. The power and moment size of the lunar surface is limited, so a special design is required. In this paper, a unique structural model of a double-auger drilling tool is designed. It is a movement analysis of lunar soil and drill pipe. We use simulated lunar soil simulations and experiments. The Hertz-Mindlin slip-free model in the discrete element software EDEM was used for numerical simulation. Given the disadvantage of the large amount of computation of discrete elements, the “embedding simulation method” proposed in this paper reduces the amount of computation. When drilling 0.4m and 1m under lunar and earth gravity, the magnitude and influence of drill pipe rotation and vertical velocity on the drag moment were analyzed. We provide the relevant technical parameters of the real unmanned drilling activities on the lunar surface. Through simulation, the rationality parameters of several groups of drill pipe drilling are obtained to ensure the smooth progress of drilling.

Analytical Study of Random Oscillations of Vibration Protection Devices with an Elliptical Hysteresis Loop for Absorbing Harmful Energies by Non-Linear Mechanical Systems and their ElasticDamping Elements

The paper discusses the analysis of forced random oscillations of a non-linear mechanical system, namely a heavy drilling machine, taking into account the damping ability of the operator (human body) as a mechanical system and the elliptical hysteresis loop of the absorption of harmful energies by the elastic-damping element.

Optimization of Machining for the Maximal Productivity Rate of the Drilling Operations

Machining processes focused primarily on the quality of surfaces and sizes of machined workpieces, as well as minimizing costs and tool wear. Existing publications related to maximizing the productivity of machining processes, present results that are in fact sub-optimal. The increase in machining regimes improves productivity but may reduce the quality of machined products. Mathematical optimization methods help find a balance between the benefits and drawbacks of machining processes. The tool life of cutters largely influences machining productivity and sets limits on machining speed. The normative tool life equations developed in research labs do not take into account the reliability of machine units and the specificities of technological processes. The normative machining speeds are suboptimal for manufacturing processes and may not maximize productivity. This paper presents a mathematical model for optimizing the cutting speed of a drilling machine tool to achieve its maximum productivity under realistic manufacturing conditions.

Design and development of a combined seedbed compactor and teff seed cum fertilizer drill machine

Teff, which is surged in other continent and a cornerstone Ethiopian grain used as injera, suffers from low yield due to outdated sowing practices and minimal use of modern fertilizers. The traditional method is inefficient, squandering seeds and fertilizer, and relying on a large number of animals for trampling. Researchers addressed this challenge by creating a new machine that combines a seedbed compactor with a tool that sows both teff seeds and fertilizer. They conducted lab tests to analyze how different settings affected the machine's performance. These settings included the speed (varying from 2.11 to 3.14 km per hour), the amount of fertilizer and seeds in the hopper (full, half, or quarter full), and the shape of the opening in the metering plate (circular, square, or a specific angled square). The weight of the compactor was also adjusted (40, 50, or 60 kg).Analysis of the results using Design Expert-13 software showed that a circular opening in the metering plate combined with a speed of 2.6 km per hour yielded optimal results, distributing 4.2 kg of seeds and 96.2 kg of fertilizer per hectare. Additionally, the compactor filled with 50 kg of sand generated a compaction force of 483.7 N. These findings satisfy the design requirements of applying 3–5 kg of seeds, 50–100 kg of fertilizer, and achieving a compaction force of 480 N per hectare. This method significantly reduces seed waste by 81 % compared to traditional techniques.

Multi-Objective Optimization Study of Annular Fluid Flow Structure in Cordless Core Drilling Tools

Multi-Objective Optimization Study of Annular Fluid Flow Structure in Cordless Core Drilling Tools

A Monitoring System for Failure Risk of Downhole Drilling Tools in Complex Formations

A Monitoring System for Failure Risk of Downhole Drilling Tools in Complex Formations

Optimizing Orchard Planting Efficiency with a GIS-Integrated Autonomous Soil-Drilling Robot

A typical orchard’s mechanical operation consists of three or four stages: lining and digging for plantation, moving the seedling from nurseries to the farm, moving the seedling to the planting hole, and planting the seedling in the hole. However, the digging of the planting hole is the most time-consuming operation. In fruit orchards, the use of robots is increasingly becoming more prevalent to increase operational efficiency. They offer practical and effective services to both industry and people, whether they are assigned to plant trees, reduce the use of chemical fertilizers, or carry heavy loads to relieve staff. Robots can operate for extended periods of time and can be highly adept at repetitive tasks like planting many trees. The present study aims to identify the locations for planting trees in orchards using geographic information systems (GISs), to develop an autonomous drilling machine and use the developed robot to open planting holes. There is no comparable study on autonomous hole planting in the literature in this regard. The agricultural mobile robot is a four=wheeled nonholonomic robot with differential steering and forwarding capability to stable target positions. The designed mobile robot can be used in fully autonomous, partially autonomous, or fully manual modes. The drilling system, which is a y-axis shifter driven by a DC motor with a reducer includes an auger with a 2.1 HP gasoline engine. SOLIDWORKS 2020 software was used for designing and drawing the mobile robot and drilling system. The Microsoft Visual Basic.NET programming language was used to create the robot navigation system and drilling mechanism software. The cross-track error (XTE), which determines the distances between the actual and desired holes positions, was utilized to analyze the steering accuracy of the mobile robot to the drilling spots. Consequently, the average of the arithmetic means was determined to be 4.35 cm, and the standard deviation was 1.73 cm. This figure indicates that the suggested system is effective for drilling plant holes in orchards.

Applying transfer learning to address data scarcity: A case study on LWD gamma ray depth-lag remediation from Volve to another gasfield

In petroleum engineering, obtaining comprehensive subsurface data is challenging due to significant costs and protective regulations. This complexity often restricts the extensive use of data-driven approaches. This study investigates the applicability of deep learning with transfer learning, to tackle this prominent challenges. Grounded in a practical fusion of engineering and geology, we address a specific issue: the depth-lagged measurements of the Logging While Drilling (LWD) tool's Gamma Ray detector, owing to its position meters behind the drill bit. Our approach uniquely integrates real-time drilling engineering parameters with the delayed Gamma time-series features, aiming to predictively correct these lagged measurements.The research extends from the Volve oil field in Norway to a distinct gas field in China, covering a wide geographical range and diverse geological conditions. The results indicated that in environments with limited data, transfer learning could enhance accuracy by up to 13% compared to traditional methods. This transition tests transfer learning's adaptability to various gasfield settings, demonstrating its potential to enhance model accuracy in data-limited environments and advocating for data-driven approaches in petroleum engineering.

Numerical Simulation and Flow Field Analysis of Porous Water Jet Nozzle Based on Fluent

The water jet nozzle is a penetrating drilling tool, which sends the pumped water to the nozzle through a high-pressure hose. It can work in a variety of working environments. When it dredges the blockage in the pipeline, its structural parameters will affect the jet flow field in the pipeline. Taking the self-propelled water jet nozzle as the research object, SolidWorks was used to establish the nozzle model with different parameter structures. Based on Fluent, the k-ε turbulence model was used to simulate the jet of nozzles with different nozzle sizes and arrangements in the pipeline. The distribution of the jet flow field and the change in velocity and displacement of nozzles with different parameters in the pipeline were compared, and then computational fluid dynamics (CFD) were used to process the simulation data for further research. The results show that when the inclination angle of the rear nozzle is 35°, the attenuation of the front jet velocity and the fluctuation of the wall fluid velocity are the smallest. When the nozzle aperture is increased from 2 mm to 3.5 mm, the vortex area inside the pipe is reduced, and the velocity attenuation of the front jet is also reduced, with the velocity attenuation rate decreasing by about 10%. This study provides a reference for the design and parameter optimization of self-propelled water jet nozzles.

Evaluation of drilling by induced delamination of hybrid biocomposites reinforced with natural fibers: A statistical analysis by RSM

Studying the drilling of a hybrid jute/palm composite material offers significant contributions to sustainable material development. Incorporating renewable jute and palm fibers represents an innovative, eco-friendly approach compared to synthetic composites. This research aims to optimize drilling parameters to reduce defects and evaluate the performance of different drilling tools, crucial for industrial applications. Drilling is performed via three different types of drills bit: High-Speed Steel, HSS-Co5 coated high-speed steel with 5% cobalt, and carbide. The drilling process involves adjusting the feed and rotational speed. Response Surface Methodology (RSM) was used to select drilling settings by validating experimentally obtained data and predicting the behavior of the structure based on cutting circumstances. The findings indicated that the most effective cutting parameters for minimizing delamination are achieved using the HSS drill bit, namely at lower feed and rotational speeds. Delamination remains below the threshold of 1.106 when the feed is 0.04 mm/rev and the rotational speed is 1592 rpm. The analysis of the results obtained using the response surface methodology indicates that the R2 coefficient for cylindricity is 0.96%. In contrast, the rate of delamination is 0.79% and the rate of circularity is 0.89%.