Aiming at the problems of large load of rotation drive system,low efficiency of torque transmission and high cost for operation and maintenance of liner steering drilling system for the horizontal well,a new method of...Aiming at the problems of large load of rotation drive system,low efficiency of torque transmission and high cost for operation and maintenance of liner steering drilling system for the horizontal well,a new method of liner differential rotary drilling with double tubular strings in the horizontal well is proposed.The technical principle of this method is revealed,supporting tools such as the differential rotation transducer,composite rotary steering system and the hanger are designed,and technological process is optimized.A tool face control technique of steering drilling assembly is proposed and the calculation model of extension limit of liner differential rotary drilling with double tubular strings in horizontal well is established.These results show that the liner differential rotary drilling with double tubular strings is equipped with measurement while drilling(MWD)and positive displacement motor(PDM),and directional drilling of horizontal well is realized by adjusting rotary speed of drill pipe to control the tool face of PDM.Based on the engineering case of deep coalbed methane horizontal well in the eastern margin of Ordos Basin,the extension limit of horizontal drilling with double tubular strings is calculated.Compared with the conventional liner drilling method,the liner differential rotary drilling with double tubular strings increases the extension limit value of horizontal well significantly.The research findings provide useful reference for the integrated design and control of liner completion and drilling of horizontal wells.展开更多
Based on the three-dimensional elastic-plastic finite element analysis of the 8"(203.2 mm)drill collar joint,this paper studies the mechanical characteristics of the pin and box of NC56 drill collar joints under ...Based on the three-dimensional elastic-plastic finite element analysis of the 8"(203.2 mm)drill collar joint,this paper studies the mechanical characteristics of the pin and box of NC56 drill collar joints under complex load conditions,as well as the downhole secondary makeup features,and calculates the downhole equivalent impact torque with the relative offset at the shoulder of internal and external threads.On the basis of verifying the correctness of the calculation results by using measured results in Well GT1,the prediction model of the downhole equivalent impact torque is formed and applied in the first extra-deep well with a depth over 10000 m in China(Well SDTK1).The results indicate that under complex loads,the stress distribution in drill collar joints is uneven,with relatively higher von Mises stress at the shoulder and the threads close to the shoulder.For 203.2 mm drill collar joints pre-tightened according to the make-up torque recommended by American Petroleum Institute standards,when the downhole equivalent impact torque exceeds 65 kN·m,the preload balance of the joint is disrupted,leading to secondary make-up of the joint.As the downhole equivalent impact torque increases,the relative offset at the shoulder of internal and external threads increases.The calculation results reveal that there exists significant downhole impact torque in Well SDTK1 with complex loading environment.It is necessary to use double shoulder collar joints to improve the impact torque resistance of the joint or optimize the operating parameters to reduce the downhole impact torque,and effectively prevent drilling tool failure.展开更多
Cutting parameters were evaluated and optimized based on multiple performance characteristics including tool wear and size error of drilled hole. Taguchi's L27, 3-level, 4-factor orthogonal array was used for the tes...Cutting parameters were evaluated and optimized based on multiple performance characteristics including tool wear and size error of drilled hole. Taguchi's L27, 3-level, 4-factor orthogonal array was used for the tests. It is shown that generally abrasive wear and built up edge (BUE) formation were seen in the tool wear, and the comer wear was also of major importance. Flank wear of the cutting tool was found to be mostly dependent upon particle mass fraction, followed by feed rate, drill hardness and spindle speed, respectively. Among the tools used, TiAlN coated carbide drills showed the best performance with regard to the tool wear as well as hole size. Grey relational analysis indicated that drill material was the more influential parameter than feed rate and spindle speed. The results revealed that optimal combination of the drilling parameters could be used to obtain both minimum tool wear and diametral error.展开更多
Drilling is regarded as the most complex manufacturing process compared with other conventional machining processes.During the drilling process,most of the energy consumed in metal cutting is converted to heat and inc...Drilling is regarded as the most complex manufacturing process compared with other conventional machining processes.During the drilling process,most of the energy consumed in metal cutting is converted to heat and increases temperature considerably.The resulting thermal phenomena are important since they influence the mode of deformation,the final metallurgical state of the machined surface,and the rate of tool wear.Hence,understanding the temperature characteristics in the drilling process is crucial for enhancing the drill performance and process efficiency.Extensive efforts have been conducted to measure and control the drilling tool temperature successively.However,very few studies have been conducted from a comprehensive perspective to review all the efforts.To address this gap in the literature,a rigorous review concerning the state-of-the-art results and advances in drilling tool temperature is presented in this paper by referring to the wide comparisons among literature analyses.The multiple aspects of drilling tool temperature are precisely detailed and discussed in terms of theoretical analysis and thermal modeling,methods for temperature measuring,the effect of cutting parameters,tool geometries and hole-making methods on temperature and temperature controlling by different cooling methods.In conclusion,several possible future research directions are discussed to offer potential insights for the drilling community and future researchers.展开更多
The lack of research on flexible drilling tool leads to limited application of ultra-short radius horizontal wells.The flexible drilling tool is different from the conventional drilling tool.The flexible drilling pipe...The lack of research on flexible drilling tool leads to limited application of ultra-short radius horizontal wells.The flexible drilling tool is different from the conventional drilling tool.The flexible drilling pipe involves a mutual transition between the structure and the mechanism during the deformation process.At the same time,the flexible drilling pipe and the eccentric guide tube,the guide tube and the wellbore generate random contact.In this paper,3-D beam elements,universal joint elements,rigid beam elements and the beam-beam contact elements are combined to establish a two-layer contact nonlinear finite element model of the flexible drilling tool in the wellbore.The dynamic relaxation method is introduced for numerical solution.The feasibility of the model and the algorithm is verified by an example.The mechanical analysis of flexible drilling tool under the four hole inclinations in the oblique section is carried out.It is found that the flexible drilling pipe has a“folded line”deformation.The contact force between the flexible drilling pipe and the guide tube is randomly distributed.The contact force between the guide tube and the wellbore in the oblique section is greater than that in the vertical section.As the hole inclinations increase,the torque and axial force transmitted to the drill bit gradually decrease.展开更多
Hole making had long been recognized as the most prominent machining process, requiring specialized techniques to achieve optimum cutting condition. Drilling can be described as a process where a multi-point tool is u...Hole making had long been recognized as the most prominent machining process, requiring specialized techniques to achieve optimum cutting condition. Drilling can be described as a process where a multi-point tool is used to remove unwanted materials to produce a desired hole. It broadly covers those methods used for producing cylindrical holes in the work piece. However, high production machining and drilling with high cutting velocity, feed and depth of cut is inherently associated with generation of large amount of heat and high cutting temperature. Such high cutting temperature not only reduces dimensional accuracy and tool life but also impairs the surface integrity of the product. In this case, high pressure coolant (HPC) is very effective to reduce temperature. When temperature is increased a large amount of tool wear appears at the drill bit. In this situation, high temperature either affects roundness of the hole or chip shape and color of chip. HPC is applied in the same direction as the drill bit. HPC has reduced temperature as well as improving roundness and also provide lubrication in the tool tip and surface interface.展开更多
In this paper,farming and crop cultivation effects of farming tools with"drill"which are invented independently in China are clarified firstly,containing horizontal cutting of soil,super deep ploughing,deep ...In this paper,farming and crop cultivation effects of farming tools with"drill"which are invented independently in China are clarified firstly,containing horizontal cutting of soil,super deep ploughing,deep loosening and not disturbing soil layer,granular soil,soil not easy to bond and harden,and one-time land preparation.It is a significant path to deeply develop and use the"five natural resources"not fully utilized by human beings(soil resources at plough bottom and below,saline-alkali land,natural rainfall,solar energy,oxygen)and realize"mitigation"of five natural disasters(flood,drought,high temperature,low temperature and climate warming).In the past 10 years,the farming tools have been applied in 40 kinds of crops in 26 provinces of China.Compared with vertical breaking of soil by traditional"plow",the amount of loose soil,water storage and dissolved oxygen in cultivated land increased by more than one time,and yield increased by 10%-50%.They have been applied in transformation of saline-alkali land in 10 provinces,and yield increased by 30%-150%.After Fenlong treatment for 1 and 2 years,biomass of sugarcane increased by 68.9%and 50.1%respectively.Net photosynthetic rates of Gramineous crops were improved by 6.82%-11.94%,while net photosynthetic rates of Legume crops were improved by 20.32%-32.08%.After"spiral drill","vertical two-knife drill","vertical three-knife drill"and other hollow series of Fenlong farming toolss were invented newly.They were the most advanced farming tools with large soil discharge and small resistance,and could be equipped in large-,medium-and small-size modern Fenlong agricultural machinery as key technology,thereby setting up a new"standard stalk"for world agricultural reform and bringing benefit to mankind.展开更多
Rotation sintering, also known as slush molding, is used to manufacture molded skins, such as dashboards or door interior panels for cars. At present, approximately 80% of such molded skins are manufactured using elec...Rotation sintering, also known as slush molding, is used to manufacture molded skins, such as dashboards or door interior panels for cars. At present, approximately 80% of such molded skins are manufactured using electroforms to achieve the complex free-form surfaces, and surface structures, such as leather graining that the industry demands. The manufacture of these electroforms is, however, time-consuming and expensive. This project aims to replace conventional electroforms with laser-drilled molds. Holes in tool molds should be drilled by using laser radiation as part of an automated process. The system consists of a robot with a fiber-laser beam source. A CAx (computer-aided x) process chain has been developed for this purpose in which the CAD (computer-aided design) data of the tool molds are processed, drill hole fields generated, and a machine-specific RC (robot control) program created. Process-specific fundamentals, such as suitable process windows and process control, have been devised to manufacture holes using fiber laser radiation The advantages of the new laser-drilled tool molds may result in substituting them for conventional electroforms, allowing old markets to be re-entered or additional markets to be created and targeted through new molds or lower costs.展开更多
Axial and torsional impact drilling technology is used to improve the drilling efficiency of hard rock formation in the deep underground.Still,the corresponding theory is not mature,and there are few correlative resea...Axial and torsional impact drilling technology is used to improve the drilling efficiency of hard rock formation in the deep underground.Still,the corresponding theory is not mature,and there are few correlative research reports on the rock-breaking mechanism of axial and torsional coupled impact drilling tools.Considering the influence of the impact hammer geometry and movement on the dynamic load parameters(i.e.,wavelength,amplitude,frequency,and phase difference),a numerical model that includes a hard formation and single polycrystalline diamond compact cutter was established.The Riedel-Hiermaier-Thoma model,which considers the dynamic damage and strength behavior of rocks,was adopted to analyze the rock damage under axial and torsional impact loads.The numerical simu-lation results were verified by the experimental results.It was found that compared with conventional drilling,the penetration depths of axial,torsional,and axial-torsional coupled impact drilling increased by 31.3%,5.6%,and 34.7%,respectively.Increasing the wavelength and amplitude of the axial impact stress wave improved the penetration depth.When the bit rotation speed remained unchanged,increasing the frequency in the axial and circumferential directions had little effect on the penetration depth.However,as the frequency increased,the cutting surface became increasingly smooth,which reduced the occurrence of bit vibration.When the phase difference between the axial and circumfer-ential stress waves was 25%,the penetration depth significantly increased.In addition,the bit vibration problem can be effectively reduced.Finally,the adjustment of engineering and tool structure parameters is proposed to optimize the efficiency of the axial-torsional coupled impact drilling tool.展开更多
The actuator is a key component of the creaming tool in drilling applications.Its jet performances determine the effective reaming efficiency.In this work,a new selective reaming tool is proposed and the RNG k-εturbu...The actuator is a key component of the creaming tool in drilling applications.Its jet performances determine the effective reaming efficiency.In this work,a new selective reaming tool is proposed and the RNG k-εturbulence model is used to calculate its internal and externalflowfields.In particular,special attention is paid to the design of theflushing nozzle.The results show that the jet originating from theflushing nozzle has a significant influence on rock cutting and blade cooling effects.In turn,the jet performances depend on geometric structure of the creaming actuator.In this framework,a conical-cylindrical nozzle with a diameter of 7 mm is initially considered as a basis to implement a strategy to optimize the structural parameters of the reaming actuator,and improve the related side tracking reconstruction technology.展开更多
基金Supported by the Project of National Natural Science Foundation of China(52234002,42230814)。
文摘Aiming at the problems of large load of rotation drive system,low efficiency of torque transmission and high cost for operation and maintenance of liner steering drilling system for the horizontal well,a new method of liner differential rotary drilling with double tubular strings in the horizontal well is proposed.The technical principle of this method is revealed,supporting tools such as the differential rotation transducer,composite rotary steering system and the hanger are designed,and technological process is optimized.A tool face control technique of steering drilling assembly is proposed and the calculation model of extension limit of liner differential rotary drilling with double tubular strings in horizontal well is established.These results show that the liner differential rotary drilling with double tubular strings is equipped with measurement while drilling(MWD)and positive displacement motor(PDM),and directional drilling of horizontal well is realized by adjusting rotary speed of drill pipe to control the tool face of PDM.Based on the engineering case of deep coalbed methane horizontal well in the eastern margin of Ordos Basin,the extension limit of horizontal drilling with double tubular strings is calculated.Compared with the conventional liner drilling method,the liner differential rotary drilling with double tubular strings increases the extension limit value of horizontal well significantly.The research findings provide useful reference for the integrated design and control of liner completion and drilling of horizontal wells.
基金Supported by the National Natural Science Foundation of China(52174003,52374008).
文摘Based on the three-dimensional elastic-plastic finite element analysis of the 8"(203.2 mm)drill collar joint,this paper studies the mechanical characteristics of the pin and box of NC56 drill collar joints under complex load conditions,as well as the downhole secondary makeup features,and calculates the downhole equivalent impact torque with the relative offset at the shoulder of internal and external threads.On the basis of verifying the correctness of the calculation results by using measured results in Well GT1,the prediction model of the downhole equivalent impact torque is formed and applied in the first extra-deep well with a depth over 10000 m in China(Well SDTK1).The results indicate that under complex loads,the stress distribution in drill collar joints is uneven,with relatively higher von Mises stress at the shoulder and the threads close to the shoulder.For 203.2 mm drill collar joints pre-tightened according to the make-up torque recommended by American Petroleum Institute standards,when the downhole equivalent impact torque exceeds 65 kN·m,the preload balance of the joint is disrupted,leading to secondary make-up of the joint.As the downhole equivalent impact torque increases,the relative offset at the shoulder of internal and external threads increases.The calculation results reveal that there exists significant downhole impact torque in Well SDTK1 with complex loading environment.It is necessary to use double shoulder collar joints to improve the impact torque resistance of the joint or optimize the operating parameters to reduce the downhole impact torque,and effectively prevent drilling tool failure.
文摘Cutting parameters were evaluated and optimized based on multiple performance characteristics including tool wear and size error of drilled hole. Taguchi's L27, 3-level, 4-factor orthogonal array was used for the tests. It is shown that generally abrasive wear and built up edge (BUE) formation were seen in the tool wear, and the comer wear was also of major importance. Flank wear of the cutting tool was found to be mostly dependent upon particle mass fraction, followed by feed rate, drill hardness and spindle speed, respectively. Among the tools used, TiAlN coated carbide drills showed the best performance with regard to the tool wear as well as hole size. Grey relational analysis indicated that drill material was the more influential parameter than feed rate and spindle speed. The results revealed that optimal combination of the drilling parameters could be used to obtain both minimum tool wear and diametral error.
基金Natural and Science Foundation of China(Grant No.52205455)Fujian Provincial Natural and Science Foundation(Grant No.2021J01560)Fujian Provincial Education and Scientific Research Foundation for Young Teachers(Grant No.JAT190006).
文摘Drilling is regarded as the most complex manufacturing process compared with other conventional machining processes.During the drilling process,most of the energy consumed in metal cutting is converted to heat and increases temperature considerably.The resulting thermal phenomena are important since they influence the mode of deformation,the final metallurgical state of the machined surface,and the rate of tool wear.Hence,understanding the temperature characteristics in the drilling process is crucial for enhancing the drill performance and process efficiency.Extensive efforts have been conducted to measure and control the drilling tool temperature successively.However,very few studies have been conducted from a comprehensive perspective to review all the efforts.To address this gap in the literature,a rigorous review concerning the state-of-the-art results and advances in drilling tool temperature is presented in this paper by referring to the wide comparisons among literature analyses.The multiple aspects of drilling tool temperature are precisely detailed and discussed in terms of theoretical analysis and thermal modeling,methods for temperature measuring,the effect of cutting parameters,tool geometries and hole-making methods on temperature and temperature controlling by different cooling methods.In conclusion,several possible future research directions are discussed to offer potential insights for the drilling community and future researchers.
基金support from the Natural Science Foundation of China(Grant numbers:51674088)supported by National Natural Science Foundation of China(Grant No.51674088).
文摘The lack of research on flexible drilling tool leads to limited application of ultra-short radius horizontal wells.The flexible drilling tool is different from the conventional drilling tool.The flexible drilling pipe involves a mutual transition between the structure and the mechanism during the deformation process.At the same time,the flexible drilling pipe and the eccentric guide tube,the guide tube and the wellbore generate random contact.In this paper,3-D beam elements,universal joint elements,rigid beam elements and the beam-beam contact elements are combined to establish a two-layer contact nonlinear finite element model of the flexible drilling tool in the wellbore.The dynamic relaxation method is introduced for numerical solution.The feasibility of the model and the algorithm is verified by an example.The mechanical analysis of flexible drilling tool under the four hole inclinations in the oblique section is carried out.It is found that the flexible drilling pipe has a“folded line”deformation.The contact force between the flexible drilling pipe and the guide tube is randomly distributed.The contact force between the guide tube and the wellbore in the oblique section is greater than that in the vertical section.As the hole inclinations increase,the torque and axial force transmitted to the drill bit gradually decrease.
文摘Hole making had long been recognized as the most prominent machining process, requiring specialized techniques to achieve optimum cutting condition. Drilling can be described as a process where a multi-point tool is used to remove unwanted materials to produce a desired hole. It broadly covers those methods used for producing cylindrical holes in the work piece. However, high production machining and drilling with high cutting velocity, feed and depth of cut is inherently associated with generation of large amount of heat and high cutting temperature. Such high cutting temperature not only reduces dimensional accuracy and tool life but also impairs the surface integrity of the product. In this case, high pressure coolant (HPC) is very effective to reduce temperature. When temperature is increased a large amount of tool wear appears at the drill bit. In this situation, high temperature either affects roundness of the hole or chip shape and color of chip. HPC is applied in the same direction as the drill bit. HPC has reduced temperature as well as improving roundness and also provide lubrication in the tool tip and surface interface.
基金Special Fund Project of Guangxi Innovation Driven Development(Guike AA17204037)Major Science and Technology Projects in Guangxi(Guike AA16380017)Team Project of Guangxi Academy of Agricultural Sciences(2015YT60).
文摘In this paper,farming and crop cultivation effects of farming tools with"drill"which are invented independently in China are clarified firstly,containing horizontal cutting of soil,super deep ploughing,deep loosening and not disturbing soil layer,granular soil,soil not easy to bond and harden,and one-time land preparation.It is a significant path to deeply develop and use the"five natural resources"not fully utilized by human beings(soil resources at plough bottom and below,saline-alkali land,natural rainfall,solar energy,oxygen)and realize"mitigation"of five natural disasters(flood,drought,high temperature,low temperature and climate warming).In the past 10 years,the farming tools have been applied in 40 kinds of crops in 26 provinces of China.Compared with vertical breaking of soil by traditional"plow",the amount of loose soil,water storage and dissolved oxygen in cultivated land increased by more than one time,and yield increased by 10%-50%.They have been applied in transformation of saline-alkali land in 10 provinces,and yield increased by 30%-150%.After Fenlong treatment for 1 and 2 years,biomass of sugarcane increased by 68.9%and 50.1%respectively.Net photosynthetic rates of Gramineous crops were improved by 6.82%-11.94%,while net photosynthetic rates of Legume crops were improved by 20.32%-32.08%.After"spiral drill","vertical two-knife drill","vertical three-knife drill"and other hollow series of Fenlong farming toolss were invented newly.They were the most advanced farming tools with large soil discharge and small resistance,and could be equipped in large-,medium-and small-size modern Fenlong agricultural machinery as key technology,thereby setting up a new"standard stalk"for world agricultural reform and bringing benefit to mankind.
文摘Rotation sintering, also known as slush molding, is used to manufacture molded skins, such as dashboards or door interior panels for cars. At present, approximately 80% of such molded skins are manufactured using electroforms to achieve the complex free-form surfaces, and surface structures, such as leather graining that the industry demands. The manufacture of these electroforms is, however, time-consuming and expensive. This project aims to replace conventional electroforms with laser-drilled molds. Holes in tool molds should be drilled by using laser radiation as part of an automated process. The system consists of a robot with a fiber-laser beam source. A CAx (computer-aided x) process chain has been developed for this purpose in which the CAD (computer-aided design) data of the tool molds are processed, drill hole fields generated, and a machine-specific RC (robot control) program created. Process-specific fundamentals, such as suitable process windows and process control, have been devised to manufacture holes using fiber laser radiation The advantages of the new laser-drilled tool molds may result in substituting them for conventional electroforms, allowing old markets to be re-entered or additional markets to be created and targeted through new molds or lower costs.
基金supported by the National Natural Science Foundation of China(52004013,U1762211).
文摘Axial and torsional impact drilling technology is used to improve the drilling efficiency of hard rock formation in the deep underground.Still,the corresponding theory is not mature,and there are few correlative research reports on the rock-breaking mechanism of axial and torsional coupled impact drilling tools.Considering the influence of the impact hammer geometry and movement on the dynamic load parameters(i.e.,wavelength,amplitude,frequency,and phase difference),a numerical model that includes a hard formation and single polycrystalline diamond compact cutter was established.The Riedel-Hiermaier-Thoma model,which considers the dynamic damage and strength behavior of rocks,was adopted to analyze the rock damage under axial and torsional impact loads.The numerical simu-lation results were verified by the experimental results.It was found that compared with conventional drilling,the penetration depths of axial,torsional,and axial-torsional coupled impact drilling increased by 31.3%,5.6%,and 34.7%,respectively.Increasing the wavelength and amplitude of the axial impact stress wave improved the penetration depth.When the bit rotation speed remained unchanged,increasing the frequency in the axial and circumferential directions had little effect on the penetration depth.However,as the frequency increased,the cutting surface became increasingly smooth,which reduced the occurrence of bit vibration.When the phase difference between the axial and circumfer-ential stress waves was 25%,the penetration depth significantly increased.In addition,the bit vibration problem can be effectively reduced.Finally,the adjustment of engineering and tool structure parameters is proposed to optimize the efficiency of the axial-torsional coupled impact drilling tool.
基金support by the Marine Economy Development Foundation of Guangdong Province(Grant No.GDNRC[2022]44).
文摘The actuator is a key component of the creaming tool in drilling applications.Its jet performances determine the effective reaming efficiency.In this work,a new selective reaming tool is proposed and the RNG k-εturbulence model is used to calculate its internal and externalflowfields.In particular,special attention is paid to the design of theflushing nozzle.The results show that the jet originating from theflushing nozzle has a significant influence on rock cutting and blade cooling effects.In turn,the jet performances depend on geometric structure of the creaming actuator.In this framework,a conical-cylindrical nozzle with a diameter of 7 mm is initially considered as a basis to implement a strategy to optimize the structural parameters of the reaming actuator,and improve the related side tracking reconstruction technology.