Conventional Drilling Research Articles

Surface Characteristics and Residual Stress Variation in Semi-Deep Hole Machining of Ti6Al4V ELI with Low-Frequency Vibration-Assisted Drilling

This study examined the impact of vibration-assisted drilling (VAD) on hole quality and residual stress in Ti-6Al-4V ELI (Extra Low Interstitials) material. Ti-6Al-4V ELI possesses excellent mechanical properties but presents challenges in machining, including chip evacuation, burr formation, and elevated cutting temperatures. VAD, particularly low-frequency vibration-assisted drilling (LF-VAD), has been explored as a potential solution to address these issues. The research compares LF-VAD with conventional drilling (CD) under various cutting and cooling conditions. LF-VAD exhibits higher maximum thrust forces under specific conditions, which result in accelerated tool wear. However, it also demonstrates lower RMS (root mean square) forces compared to CD, offering better control over chip formation, reduced burr formation, and improved surface roughness within the hole. Furthermore, LF-VAD generates greater compressive residual stresses on the hole’s inner surface compared to CD, suggesting enhanced fatigue performance. These findings indicate that LF-VAD holds promise for improving the hole’s surface characteristics, fatigue life, and overall component durability in Ti-6Al-4V machining applications.

Impact of different parameters in the drilling of CFRPs with nanocrystalline diamond coated tools

The drilling process of composite materials, such as the carbon fiber reinforced polymer (CFRP), constitutes a challenging task due to their inhomogeneous and anisotropic characteristics, besides the highly abrasive wear behaviour of their fibers. Accordingly, machining parameters should be carefully studied to optimize the process, leading to a better surface quality (avoiding defects in the CFRP) and to a lower wear behaviour of the cutting tool. This study proposed to test the drilling of a CFRP with a thermoplastic matrix using two different tool geometries (conventional and double-point angle drill) and varying two parameters, feed (f) and spindle speed (n), each one with two levels. It was concluded that the double-point angle drill with lower spindle speeds generates lower thrust force and torque values, as well as better hole quality. Higher spindle speeds combined with lower feeds result in fractured chips, in contrast with continuous chips for the other combinations.

Exploring Underbalance Drilling: A Comprehensive Review

Underbalance Drilling (UBD) is an advanced drilling technique employed in oil and gas industry to improve well productivity and reduce formation damage. In conventional drilling, overbalance conditions are maintained in order to prevent the influx of formation fluids. In contrast, UBD involves maintaining a hydrostatic pressure lower than the formation pressure during drilling operations. UBD offers several advantages, such as increasing drilling rates, reducing formation damage, improving wellbore stability. By preventing the flow of drilling fluids in to the formation, UBD reduces the risk of formation plugging and improves the recovery of hydrocarbons. This technique is particularly beneficial for depleted reservoirs or formations prone to lost circulation problems. Despite its advantages, proper planning and execution are essential for UBD to manage the associated risks, such as wellbore stability challenges and the potential for unexpected influx of formation fluids. UBD involves the use of specialized equipment such as BOPs, RCDs to manage the hydrostatic pressure of well and control the influx of formation fluids. In conclusion, a comprehensive understanding of UBD is essential for maximizing hydrocarbon recovery alongside a commitment to operational safety and environmental sustainability in the ever- changing landscape of the oil and gas industries.

Transient temperature field simulation and sensitivity factors analysis of riserless mud recovery system

The riserless mud recovery system (RMR) is different from conventional offshore drilling in that both the drill pipe and the return pipeline are exposed to seawater, which affects the entire temperature field distribution, and then affects the pressure field change of the whole system. Moreover, too low a temperature will lead to the emergence of gas hydrate. In order to accurately grasp the temperature field distribution and temperature regulation mechanism of the RMR system, a transient temperature field model was established considering frictional heat generation. The changing characteristics of temperature were discussed from two dimensions of time and space, and the influence of different factors on temperature was analyzed. The results show that the established transient temperature field model is more reliable and time-efficient. The variation of temperature with time and space is opposite in seawater and formation. Injection temperature and geothermal gradient are positively correlated with temperature. Displacement, drilling fluid density, and specific heat are positively correlated with temperature in the seawater section and negatively correlated with temperature in the formation section, while thermal conductivity shows the opposite trend. The research results can provide theoretical support for pressure control of the RMR system and the safe exploitation of hydrate.

Osseodensification: An Alternative to Conventional Osteotomy in Implant Site Preparation: A Systematic Review.

Osseodensification is an innovative method of preparing the implant osteotomy using drills that promote bone self-compaction. The main objective of this technique is to promote peri-implant bone densification and compaction of autologous bone and to increase the primary stability of the implant due to the viscoelastic characteristics of the alveolar bone using Densah® burs in a counterclockwise direction at a speed of 800 to 1500 rpm. The objective of this review is the analysis of the scientific literature regarding the applicability of the osseodensification technique in oral implantology. The Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines were used and registered at PROSPERO. The search strategy included electronic databases from 2016 to 2023 and was performed by two independent reviewers. The results demonstrate the advantage of the osseodensification technique in relation to conventional drilling, allowing an increase in the bone density and primary stability of the implant, bone density, and bone-implant contact. The osseodensification technique can be applied in different clinical situations: sub-antral bone grafts, narrow alveolar bone crests, low-density bone areas, and immediate implant placement in post-extraction sockets.

The Influence of Internally Cooled Drill Bits on Cutting Dynamics and Workpiece Hardness Monitoring in Stone Machining

Drill bits with internal cooling capabilities are still not employed in stone machining practices within shop floor environments. Therefore, a conventional industrial drill bit used in stone machining was subject to a redesign wherein an axial cooling channel was machined throughout its body. A comparison was drawn between the standard drill bit without cooling capabilities and the redesigned drill bit, which used compressed air as a cooling medium. The experiment was performed by drilling three types of stone samples varying in hardness with nine combinations of cutting speed and feed rate. During the machining process, two types of process signals were continuously measured—namely, cutting forces and vibrations. Additionally, the cutting edges of the drill bits were inspected after a specific number of drilling cycles using a vision system. The primary objective of this study was to compare the cutting forces and tool wear dynamics achieved by those two drill bits. Furthermore, the usage of vibration signals in the classification of stone hardness during machining with an internally cooled drill bit was additionally analyzed. The results of this study unveiled improvement in minimizing cutting forces, vibrations, and the intensity of tool wear when utilizing an internally cooled drill bit. Even though the machining system generally exhibited lower vibrations, vibration signals again demonstrated commendable efficacy in classifying stone hardness.

Preliminary study on friction stir spot welding of plastic sheets with non-metallic tools

In recent years, 3D printing technology of engineering plastics is often used in various fields to develop prototypes of parts. Friction stir spot welding of lap joints of different engineering plastics has considerable potential for industrial applications. This study used a self-developed non-metallic tool to successfully form the PLA joints on a modified conventional drilling machine. The results show the average downward force and average welding torque decreased with increasing the rotating speeds and dwell times. The stir zone width is slightly increased with increasing the rotating speed, and its signification increased with the dwell time. The increase in stir zone width on the different rotating speeds and the dwell times is similar to the increasing trend in average temperature. The average temperature multiplied by the dwell time defined as the bonding factors is similar to the diffusion bonding. The stir zone width is increased with increasing the bonding factor because there has still some distance between the shoulder to the lap surface, the stir action by the shoulder is not easy riches to the lap surface, so the stir zone only occurs within the FSP zone and the stir zone width never exceeds the shoulder diameter.

High Temperature Inertial Navigation Sensors, Electronics and Packaging for reliable 300°C Operation

Conventional oil and gas drilling measurement while drilling (MWD) systems are typically designed to operate at temperatures <200°C. To increase the efficiency of drilling unconventional geothermal wells, downhole MWD tools are needed that can operate in the unique thermal challenges encountered in enhanced geothermal systems (EGS). GE demonstrated a 300°C downhole navigation system. The system utilizes GE’s internally developed state-of-the-art MEMS multiple ring Gyroscope (MRG), and a high temperature gyroscope control and readout application specific integrated circuit (ASIC). The MRG, ASIC and associated high temperature, high reliability packaging were integrated to demonstrate the performance and functionality of the gyroscope across the temperature range from room temperature to 300°C. Specialized long-term capable high temperature test platforms were developed to enable the characterization and testing of the gyroscope system and utilized to validate application-relevant lifetime capability.

Evaluation of different well control methods concentrating on the application of conventional drilling technique

Over the past few decades, engineering failures have existed, and lack of knowledge, and safety practices have led to various catastrophic events of blowouts causing countless casualties and injuries to workers and individuals all around the world. Well control is a technique in oil and gas activities specifically when drilling oil and gas wells. Hydrostatic pressure and formation pressure should be a priority to prevent reservoir fluids from infiltrating the wellbore. The primary well control is commonly the primary barrier using the fluid column to prevent uncontrolled formation fluid flow into the wellbore by preserving pressure more substantial than formation pressure. The secondary well control provides the same purpose but involves using a piece of equipment known as a Blowout Preventer. The objective of this paper is to evaluate the effectiveness of different well control techniques of various well control methods, including the commonly used in petroleum engineering focusing on the application of conventional drilling. This study was conducted through a literature review. The analysis of the case studies synthesized to provide a comprehensive overview of the various well control methods. The findings suggested that conventional drilling techniques can be effective in controlling wellbore pressures, however, limitations existed in certain situations. Moreover, the parameters required controlling the well during a kick or a blowout is discussed to succeed in the application of well control methods in the oil and gas industry.

Clinical Comparison of Vascular Bleeding Time Creep Between Osseodensification and Conventional Drilling of Implant Osteotomy Sites.

This study compared the onset of vascular bleeding between osseodensification and conventional drilling of implant osteotomy sites. Patients with type III trabecular bone requiring a single missing tooth replacement were included and allocated to either Group A (test) or Group B (control). In Group A, the osseodensification group (OD), an implant osteotomy was carried out using Densah Burs (Versah) in the counterclockwise direction; in Group B, the standard drilling group (SD), Densah Burs were run in the clockwise direction. An endoscope was introduced into the osteotomy to visualize and measure the time taken for initiation of bleeding (BI) and for blood to fill the osteotomy site (BF). A total of 40 osteotomy sites (23 in the maxilla and 17 in the mandible) were included in this cross-sectional study. The mean age of study participants was 50.1 ± 8.28 years. The mean BI time for Groups A and B was 18.54 ± 2.48 seconds and 16.89 ± 1.92 seconds, respectively (P = .02); the mean BF time for Groups A and B was 41.92 ± 3.19 seconds and 37.95 ± 2.73 seconds, respectively (P < .001). Osseodensification does not seem to negatively affect or induce loss of bone vascularity. Clinicians should note that osseodensified sites might take slightly longer to fill with blood following an osteotomy.

Improving hole quality of thick CFRP laminates through a laser-mechanical compound drilling process

Conventional mechanical drilling of thick carbon fiber reinforced plastic (CFRP) composite laminates is prone to machining-induced defects such as burrs, delamination, and severe tool wear. However, pulsed laser drilling as an improved strategy results in hole taper and the formation of a heat-affected zone (HAZ). Herein, a new laser-mechanical composite drilling process is proposed, which combines the advantages of pulsed laser drilling for avoiding tool wear and twist drilling for achieving high dimensional accuracy, significantly improving the drilling quality of thick CFRP laminates. The evolution mechanism of the hole taper and HAZ with processing conditions in pulsed laser drilling is investigated. Furthermore, a theoretical model is established to reveal the material removal mechanism during the reaming process. The thrust force variation, drilling quality and tool wear are analyzed and verified by comparative experiments. The results show that due to the shielding effect from the surface materials, the maximum hole taper and HAZ at the hole exit reach up to 37.5° and 650 μm, respectively, which can be removed effectively by subsequent reaming operations. Due to its small amount of material removal, the peak thrust force and the average thrust force in laser-mechanical drilling are only 53.8 % and 37.6 % of the critical thrust force of delamination, respectively, which can effectively inhibit delamination. Compared with direct twist drilling, the average wear of the main cutting edge in laser-mechanical drilling is decreased by 60.87 %, which greatly reduces the size of the delamination by 55 %.

Weed control performance of different sowing modes in organic wheat production

Serious weed infestations are one of the main factors restricting yield increases in organic wheat. The effect of different sowing modes on the growth competitiveness between wheat and weeds under field conditions was studied to explore new methods of agronomic weed control in organic wheat fields. In 2019 and 2020, the spring wheat cultivar “Yongliang 4” was sown using three sowing modes: wide-range uniform sowing (W0), wide-range 7 cm sowing (W7) and conventional drill sowing (CK). The differences in agronomic traits, light transmission rate, wheat grain yield and quality, weed density and weed biomass at different days after sowing (DAS) were studied. The results showed that compared with the CK treatment, the W0 treatment significantly increased the morphological indices (plant height, flag leaf area, leaf area per plant), photosynthetic physiological indices (flag leaf SPAD value, net photosynthetic rate) and population indices (leaf area index, dry matter weight) of wheat at the flowering stage. The light transmission rates in different layers of the wheat canopy in the W0 and W7 treatments were significantly reduced. The density of root length, root surface area, root volume, and root weight in different soil layers in the W0 treatment significantly increased. The grain yields of the W0 and W7 treatments were significantly increased by 28.2% and 15.0%, respectively. The total weed density and total weed biomass of the W0 and W7 treatments decreased significantly at different DAS. Correlation analysis showed that total weed biomass and total weed density were significantly negatively correlated with leaf area index, dry matter weight, leaf area per plant, grain yield, grain protein content, density of root length, root surface area, root volume, and root weight and significantly positively correlated with light transmission rate in the upper, middle and lower parts of the wheat canopy layer. In conclusion, wide-range uniform sowing increases wheat competitiveness against weeds for aboveground and underground resources, suppresses weed germination and growth, and improves wheat grain yield and quality by establishing an appropriate population canopy structure and well-developed root system of organic wheat.

Relative Comparison in Performance Evaluation of Happy Seeder and Conventional Seed Drill under Rice-Wheat Cropping System

The study evaluates the Happy Seeder's performance in sowing wheat crops in combined harvested paddy fields in the Moradabad region, aiming to mitigate crop residue burning and promote sustainable agriculture. The rice-wheat cropping system in the Indo-Gangetic region generates significant crop residues after combine harvesting, leading to environmental and health hazards. The Happy Seeder, designed to cut and lift rice straw while sowing wheat, offers a promising solution to manage residues and prevent burning. Various parameters, including forward speed, crop residue condition, and soil bulk density, were investigated as independent variables to assess the Happy Seeder's performance. Results show an actual field capacity of 0.23 to 0.29 ha/, with fuel consumption ranging from 4.12 to 4.40 l/h at different speeds. Field efficiency varied from 43.4% to 65%, with the best performance at 3.5 km/h forward speed. Economically, the Happy Seeder proves to be a cost-effective alternative, saving 613.83 ₹/compared to conventional seed drills. Farmers responded positively to its labor-saving features, timely sowing, and eco-friendly benefits, leading to improved crop growth and higher yields. In conclusion, the Happy Seeder demonstrated efficiency, economic viability, and positive farmer feedback, making it a valuable tool for sustainable agriculture in the Moradabad region and beyond. Its adoption can contribute to residue management, improved soil health, and increased crop productivity, fostering an environmentally conscious rice-wheat cropping system in the Indo-Gangetic region.

A Comparative Assessment of Primary Implant Stability Using Osseodensification vs. Conventional Drilling Methods: A Systematic Review.

Osseodensification is a novel biomechanical bone preparation technique that has been established to replace conventional bone drilling and therefore will optimize the implant site. The purpose of this systematic review was to comparethe implant stability obtained by osseodensification drilling to those associated with conventional drilling techniques. An electronic search was performed in the PubMed, Scopus, EMBASE, Cochrane Oral Health Group, and Dentistry and Oral Science Source databases searched through Elton B. Stephens Company (EBSCO) for potentially relevant publications in the English language from January 2013 to December 2022. Randomized clinical trials (RCTs) and non-randomized studies of interventions (NRSIs), contrasting osseodensification drilling with conventional drilling, studies documenting implant stability quotient (ISQ), and studies reporting the immediate outcome and at least three months of follow-up after dental implant placement were included.Two independent investigators evaluated the quality of the reviewed studies to determine the risk of bias using the version 2 of Cochranerisk-of-bias (RoB)toolfor RCTs (RoB 2) and RoB for NRSIs (ROBINS-I). Majority of the studies showed that bone density wassignificantly higher in the osseodensification group.The overall RoB for the NRSIs was reported to be low with respect to confounding, selection, classification, incomplete data, deviance from interventions, outcomeevaluation, and selective reporting. The quality assessment of the RCT studies included in the review using the RoB 2 tool showed a high overall risk. The findings of the current review reveal that osseodensification drilling exhibited higher resonance frequency analysis (RFA) and ISQ values than conventional drilling protocols. Similarly, when osseodensification regions were contrasted with traditional drilling, bone density at the implant surface was augmented.

The principal factor–a three-dimensional golden-section drill bit optimizing menthod based on formation anti-drilling ability

The use effect of a bit has a direct influence the on rate of penetration, drilling cost, and wellbore quality. Conventional drill bit selection methods suffer from uncertainties in formation anti-drilling ability, lack of reference data in new areas, and overreliance on data, which results in overfitting in machine learning, inaccurate selection, and difficulty in meeting on-site construction requirements. In light of these challenges, this paper proposes a novel drill bit selection method based on the principal-factor three-dimensional golden-section method and considering the drillability similarity of formation resistance to drilling. First, grey relational analysis is employed to study the drillability similarity of encountered formations in each spud and formations with high grey relational degree and good drillability similarity are divided into the same category to expand the drill bit selection database. Second, a principal-factor three-dimensional golden-section drill bit optimization model is developed by comprehensively considering the effects of mechanical and hydraulic parameters on drill bit performance, and a three-dimensional golden-section discriminant surface is plotted. Finally, the preferred drill bit is selected from the region above the golden-section surface for on-site applications. The results indicate that formations with a grey relational degree exceeding 0.55 exhibit good similarity of anti-drilling ability. The TS1678BP drill bit, selected through the principal-factor three-dimensional golden-section method, exhibits exceptional performance in a two-step drilling operation. It attains an IADC wear grade of 1-2-BU-A-X-IX-WT-PR, achieves an average mechanical drilling speed of 10.50 m/h, surpassing adjacent wells by 31.25% (8 m/h), and exceeding construction requirements by 16.67% (9 m/h). These findings illustrate that the drill bit selection method proposed in this paper provides scientific guidance for an on-site drill bit selection.

Identification of the Production of Small Holes and Threads Using Progressive Technologies in Austenite Stainless Steel 1.4301.

This article focuses on the technologies used by a manufacturing company to produce threads in chrome-nickel steel 1.4301 at specific sheet thicknesses. To enhance production quality, two specific technologies were chosen for hole formation, considering the requirements of the company. Both conventional drilling and nonconventional laser cutting methods were evaluated as potential techniques for hole production. Conventional thread-cutting technology and progressive forming technology were employed to create metric internal threads. The aim of integrating these diverse technologies is to identify the optimal solution for a specific sheet thickness in order to prevent the occurrence of defective threads that could not fulfil the intended purpose. The evaluation of the threads and holes relies on the examination of surface characteristics, such as the quality of the surface, as well as the lack of any signs of damage, cracks, or burrs. Furthermore, residual stresses in the surface layer were monitored because these stresses have the potential to cause cracking. Additionally, extensive monitoring was performed to guarantee that the form and size of the manufactured threads were correct to ensure smooth assembly and optimal functionality.

Justification of drilling parameters of a typical well in the conditions of the Samskoye field

In the Republic of Kazakhstan, there is a noticeable shortage of water resources, which is a consequence of the natural features of its territory and climate. In particular, there are big problems in the water supply to the Mangystau region. The main source of water in the region is the Samskoye groundwater field. In this work, the conditions of the Samskoye field are typified, the method and technological parameters for drilling a typical well are selected and substantiated. It has been established that rotary drilling with reverse circulation in the conditions of the Samskoye field has significant advantages. The maximum possible production rate of drilling with reverse circulation, taking into account the limited thickness of the aquifer, is 4.3 times higher than with rotary drilling with direct circulation and 2.5 times higher than with percussion drilling. With the same filter pipe diameter, the greatest possible thickness of the gravel pack layer in reverse circulation drilling is 15 times greater than for conventional rotary drilling and 3.7 times greater than for percussion drilling. Thus, the use of rotary drilling with reverse circulation will solve an important problem – the provision of domestic and drinking water supply to the area.

Evaluation of Geometric Defects Produced in Abrasive Water Jet Drilling of Steel S275JR

Drilling of metal alloys is an operation that is still performed today in many industrial sectors such as aeronautics, automotive or civil engineering. This is mainly due to the high number of mechanical joints that must be made in structural elements. However, it is known that conventional drilling operations can generate defects on the machined surface mainly due to the effect of temperature on the tool and the material. For this reason, a non conventional process such as abrasive water jet machining (AWJM) is ideal for this type of operation. The decrease in temperature along the process minimizes the defects generated while keeping a high surface finish on the machined part. Therefore, this research has been carried out, where a 2 mm thick S275JR steel has been drilled by abrasive water jet. An experimental methodology has been developed to carry out the drilling. The input parameters include hydraulic pressure (P), stand of distance (SOD), abrasive flow rate (AMF) and traverse speed of the tool head (TS). In order to carry out the experiment satisfactorily, micro-drilling trials have been carried out leaving the TS parameter fixed in order to know the behavior of the material against the kinetic energy presented by the water jet equipment. These holes have been analyzed by means of the geometrical defects obtained in the form of diameter and kerf taper angle. Finally, the most relevant conclusions of the research have been developed, where it is emphasized that kerf taper (KT) angle increases drastically with the increase in SOD, giving greater results in area and with a greater amount of deformations and projections.

Comparative study on machining performance of conventional and ultrasonic-assisted drilling of carbon fiber-reinforced polyetheretherketone composite

Comparative study on machining performance of conventional and ultrasonic-assisted drilling of carbon fiber-reinforced polyetheretherketone composite

Comparative Study of Conventional Rotary and Rotary-Percussion Techniques in Grout Hole Drilling from the Perspectives of Time, Cost, and Quality

A dam foundation structure is usually strengthened by grouting, which begins with grout hole drilling. This paper aims to examine a comparison between conventional rotary and rotary-percussion drilling techniques in a drilling case study of the Tugu Dam Project, from the perspective of time, cost, and quality comprehensively. Primary data was obtained from the field investigation and interviews. Secondary data was gathered from available project documents of the PT Wijaya Karya-APTA KSO Project Contractor. The findings have highlighted that the implementation of the rotary-percussion technique for grout hole drilling is better than conventional rotary drilling. There are 16 days of time-saving and 3.84% cost-savings for the rotary-percussion technique, as a result of faster rate of penetration. The quality of grouting work using the rotary-percussion drilling technique tends to be of better quality, although there is a shortcoming due to the limited drilling depth of only 5m particularly.