The Experts below are selected from a list of 651 Experts worldwide ranked by ideXlab platform
Ping Chen - One of the best experts on this subject based on the ideXlab platform.
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the vibration characteristics of drillstring with Positive Displacement Motor in compound drilling part 2 transient dynamics and bit control force analysis
International Journal of Hydrogen Energy, 2018Co-Authors: Guangjian Dong, Ping ChenAbstract:Abstract The transient dynamics of a drill string and the dynamic characteristics of bit control force during compound drilling have not been elucidated yet. A numerical simulation model of drill string with a Positive Displacement Motor was established to analyze the transient dynamics of drill string. The calculation model of dynamic bit control force was proposed based on the results of the transient dynamics of drill string. The results show that, when compared with conventional drilling, the impact frequency and the mean and peak values of drill string–wellbore interaction were larger. The effect of compound drilling on the lateral vibration acceleration of drill string was greater than that on the longitudinal vibration acceleration. A heightened build-up effect was caused by the increase of weight on bit. The larger bend angle and higher position of the stabilizer were not conducive to the stable control of the well trajectory. The increased outer diameter of the stabilizer could reduce the build-up effect of the bottom hole assemble to a certain extent. The driller in the field control of a well trajectory should be based on the complex dynamics of the numerical model of the bottom hole assemble during compound drilling.
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the vibration characteristics of drillstring with Positive Displacement Motor in compound drilling part1 dynamical modelling and monitoring validation
International Journal of Hydrogen Energy, 2018Co-Authors: Guangjian Dong, Ping ChenAbstract:Abstract The storage of hydrogen energy is one of the key difficulties in the efficient use of hydrogen. The most important thing for different storage methods is to establish the aisles of the hydrogen to storage space, and efficiently drill a few high-quality well holes. Compound drilling is one of the alternative technologies. However, the bit-rock interaction and the drill string-borehole interaction make the movement of bottom hold assembly more complex and increase the difficulty of well trajectory control. The vibration characteristics of drill string during compound drilling are not clear. The numerical simulation model of drill string with Positive Displacement Motor is established by considering the bit-rock interaction, the rock failure behavior, the drill string-borehole interaction and the drill string structural. The mechanical parameters of shale for the numerical model are measured by wave velocities method. The simulation model is verified by the measuring and Motoring data of axial force in the field. The rock element damage failure rate of compound drilling is greater than conventional drilling. The axial force and torque of bit of drill string in compound drilling is greater than that in the conventional drilling. The drill string is in contact with the wellbore in a more complicated way during compound drilling. The research results are benefit for optimal design of borehole quality.
Guangjian Dong - One of the best experts on this subject based on the ideXlab platform.
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the vibration characteristics of drillstring with Positive Displacement Motor in compound drilling part 2 transient dynamics and bit control force analysis
International Journal of Hydrogen Energy, 2018Co-Authors: Guangjian Dong, Ping ChenAbstract:Abstract The transient dynamics of a drill string and the dynamic characteristics of bit control force during compound drilling have not been elucidated yet. A numerical simulation model of drill string with a Positive Displacement Motor was established to analyze the transient dynamics of drill string. The calculation model of dynamic bit control force was proposed based on the results of the transient dynamics of drill string. The results show that, when compared with conventional drilling, the impact frequency and the mean and peak values of drill string–wellbore interaction were larger. The effect of compound drilling on the lateral vibration acceleration of drill string was greater than that on the longitudinal vibration acceleration. A heightened build-up effect was caused by the increase of weight on bit. The larger bend angle and higher position of the stabilizer were not conducive to the stable control of the well trajectory. The increased outer diameter of the stabilizer could reduce the build-up effect of the bottom hole assemble to a certain extent. The driller in the field control of a well trajectory should be based on the complex dynamics of the numerical model of the bottom hole assemble during compound drilling.
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the vibration characteristics of drillstring with Positive Displacement Motor in compound drilling part1 dynamical modelling and monitoring validation
International Journal of Hydrogen Energy, 2018Co-Authors: Guangjian Dong, Ping ChenAbstract:Abstract The storage of hydrogen energy is one of the key difficulties in the efficient use of hydrogen. The most important thing for different storage methods is to establish the aisles of the hydrogen to storage space, and efficiently drill a few high-quality well holes. Compound drilling is one of the alternative technologies. However, the bit-rock interaction and the drill string-borehole interaction make the movement of bottom hold assembly more complex and increase the difficulty of well trajectory control. The vibration characteristics of drill string during compound drilling are not clear. The numerical simulation model of drill string with Positive Displacement Motor is established by considering the bit-rock interaction, the rock failure behavior, the drill string-borehole interaction and the drill string structural. The mechanical parameters of shale for the numerical model are measured by wave velocities method. The simulation model is verified by the measuring and Motoring data of axial force in the field. The rock element damage failure rate of compound drilling is greater than conventional drilling. The axial force and torque of bit of drill string in compound drilling is greater than that in the conventional drilling. The drill string is in contact with the wellbore in a more complicated way during compound drilling. The research results are benefit for optimal design of borehole quality.
Jie Zhang - One of the best experts on this subject based on the ideXlab platform.
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Design and Mechanics Analysis of the Deep Cavity Tapered Roller Thrust Bearing Used in a Positive Displacement Motor
'Faculty of Mechanical Engineering and Naval Architecture Univ. of Zagreb', 2019Co-Authors: Jie Zhang, Yang Liu, Han ZhangAbstract:Positive Displacement Motor (PDM) is one of the most commonly used deep hole power drills. The thrust ball bearing unit is one of the vulnerable parts of the PDM. Failure of the thrust bearing greatly affects the PDM and can drastically reduce its drilling efficiency. In order to improve its service life, we have designed a new deep cavity tapered roller thrust bearing. In this analysis, we will evaluate the new product. In the past, results have shown that there is a serious stress concentration at both ends of the roller. The new deep cavity design will result in the improvement of the stress factor of tapered rollers. If the cavity depth and diameter are too small, the stress concentration at both ends of the roller becomes serious. If they are too large, the stress on the middle part of the roller is also too high. Deformation of the roller increases with an increase in the deep cavity’s length and depth. Consequently, the deep cavity design can improve the PDM
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fracture failure analysis and research on special taper thread of cardan shaft shell of pdm
Engineering Failure Analysis, 2018Co-Authors: Yang Liu, Zhanghua Lian, Chengyu Xia, Liqin Qian, Jie ZhangAbstract:Abstract The secondary crack is located near the main crack as per the macro examination and micro analysis on the fracture of a PDM (Positive Displacement Motor) shell with special taper thread, and serious defects are produced at the bottom of thread surface in the process of main crack fracture. Scanning electron microscopy observation indicates that the shear fracture point is positioned at shear fracture zone and convex of thread bottom tearing crack of sample 1#. Based on field data and type design of special thread, the matching model of special taper thread of cardan shaft shell is established in this paper, and numerical simulation of threaded connection is carried out under three different borehole curvatures. Results indicate that stress and Displacement of thread increase with the borehole curvature. When the curvature reaches 30°/30 m, the maximum Von Mises stress is 967.8 MPa, which is close to the yield stress of thread material. The maximum stress occurs at the bottom of the first tooth according to the actual fracture location. Comprehensive analysis reveals that the effect of bending load occurs many times at the bottom of well. Moreover, thread surface defects result in large stress of thread, and form the weakest micro cracks at the bottom of thread. In addition, the crack occurs in the smooth area, and then rapidly extends to the shear lip, which leads to failure and even fracture of threaded connection of shell.
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thermal failure of rubber bushing of a Positive Displacement Motor a study based on thermo mechanical coupling
Applied Thermal Engineering, 2014Co-Authors: Chuanjun Han, Jie Zhang, Zheng LiangAbstract:Abstract Viscoelastic hysteresis of the rubber material often causes thermal failure of PDM (Positive Displacement Motor) stator bushing. Combining heat transfer modeling with material testing, finite element method was used to calculate the temperature field and thermal stress of the bushing, and their sensitivity to Poisson ratio, mud pressure, rotor speed and formation temperature. The results show that the maximum thermal stress occurs at the bottom of the arc of the bushing, and the maximum deformation occurs at the arc top. The distribution of temperature field appears oval-shaped and the temperature gradient is large. Bushing's temperature decreases with the increasing of formation temperature, but increases with the increasing static pressure and the rotor speed. The rubber bushing's thermal failure modes observations in practice are consistent with the calculation results.
Yang Liu - One of the best experts on this subject based on the ideXlab platform.
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fracture failure analysis and research on drive shaft of Positive Displacement Motor
Engineering Failure Analysis, 2019Co-Authors: Yang Liu, Zhanghua Lian, Chengyu Xia, Liqin Qian, Shaohu LiuAbstract:Abstract In this paper, microstructures and mechanical properties of the fractured drive shaft are investigated by visual inspection, metallographic analysis, scanning electron microscopy, and tensile and impact tests. The composition, structure and mechanical properties of the drive shaft materials are tested to meet the standards. The fracture surface is mainly characterized by dimples and a small amount of quasi-cleavage by microscopic analysis, which indicates that the fracture surface is dominated by ductile fracture. At the bottom of the sample pit, there are a large number of grey inclusions, which are turned to be iron oxides through EDS spectrum analysis. So, the existence of a large number of iron oxide inclusions in the metal will inevitably have a serious impact on the performance of drive shaft. The finite element analysis shows that the stress on the cylindrical surface of the external thread near the shoulder will gradually increase greatly and the rupture risk will increase with the increase of the torque and that it will also fails due to the relatively high stress on the root of the first tooth of thread. The maximum stress near the thread shoulder is close to the yield limit of the material when the borehole curvature is larger and the bending load will lead to stress concentration on the optical axis section at the shoulder, which will affect the safety of drive shaft. Because there are a large number of inclusions in raw materials and the conditions in the well are complex, the carrying capacity of drive shaft decreases and fracture of the drive shaft is finally caused. The maximum stress value of the improved drive shaft is lower than that before the improvement through the comparative analysis. It shows that the safety factor and service life of the drive shaft can be improved by the improved design.
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Design and Mechanics Analysis of the Deep Cavity Tapered Roller Thrust Bearing Used in a Positive Displacement Motor
'Faculty of Mechanical Engineering and Naval Architecture Univ. of Zagreb', 2019Co-Authors: Jie Zhang, Yang Liu, Han ZhangAbstract:Positive Displacement Motor (PDM) is one of the most commonly used deep hole power drills. The thrust ball bearing unit is one of the vulnerable parts of the PDM. Failure of the thrust bearing greatly affects the PDM and can drastically reduce its drilling efficiency. In order to improve its service life, we have designed a new deep cavity tapered roller thrust bearing. In this analysis, we will evaluate the new product. In the past, results have shown that there is a serious stress concentration at both ends of the roller. The new deep cavity design will result in the improvement of the stress factor of tapered rollers. If the cavity depth and diameter are too small, the stress concentration at both ends of the roller becomes serious. If they are too large, the stress on the middle part of the roller is also too high. Deformation of the roller increases with an increase in the deep cavity’s length and depth. Consequently, the deep cavity design can improve the PDM
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fracture failure analysis and research on special taper thread of cardan shaft shell of pdm
Engineering Failure Analysis, 2018Co-Authors: Yang Liu, Zhanghua Lian, Chengyu Xia, Liqin Qian, Jie ZhangAbstract:Abstract The secondary crack is located near the main crack as per the macro examination and micro analysis on the fracture of a PDM (Positive Displacement Motor) shell with special taper thread, and serious defects are produced at the bottom of thread surface in the process of main crack fracture. Scanning electron microscopy observation indicates that the shear fracture point is positioned at shear fracture zone and convex of thread bottom tearing crack of sample 1#. Based on field data and type design of special thread, the matching model of special taper thread of cardan shaft shell is established in this paper, and numerical simulation of threaded connection is carried out under three different borehole curvatures. Results indicate that stress and Displacement of thread increase with the borehole curvature. When the curvature reaches 30°/30 m, the maximum Von Mises stress is 967.8 MPa, which is close to the yield stress of thread material. The maximum stress occurs at the bottom of the first tooth according to the actual fracture location. Comprehensive analysis reveals that the effect of bending load occurs many times at the bottom of well. Moreover, thread surface defects result in large stress of thread, and form the weakest micro cracks at the bottom of thread. In addition, the crack occurs in the smooth area, and then rapidly extends to the shear lip, which leads to failure and even fracture of threaded connection of shell.
Xudong Wang - One of the best experts on this subject based on the ideXlab platform.
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numerical modeling of dynamic behavior and steering ability of a bottom hole assembly with a bent housing Positive Displacement Motor under rotary drilling conditions
Energies, 2018Co-Authors: Yingjie Chen, Anping Tong, Zhaoxue Guo, Xudong WangAbstract:Fully rotary drilling is one of many useful technologies used for the exploitation of petroleum and geothermal resources, but fully rotating drill-strings are extremely complicated. Therefore, according to the Hamilton principle, a non-linear coupled bottom hole assembly (BHA)-bit-formation-wellbore model is proposed for BHAs with bent-housing Positive Displacement Motor using the finite element method to investigate the dynamic behavior and steering ability under fully rotary drilling. The impact force, acceleration, axial loading, torque, and dynamic stress were simulated, and factors influencing the dynamic steering forces were investigated. The results indicate that the impact force, acceleration, axial loading, torque, and dynamic stress under fully rotary drilling are much higher than under conventional drilling. The numerical simulation and field test in well B confirmed that the rotation of the drill-string is conducive to the hold-on of the deviation angle. With the increase in the weight-on-bit, bend angle, and stabilizer height, the deflecting force on a drill bit increases. Conversely, with the increase in stabilizer diameter, the deflecting force on the drill bit decreases; the lower the deflecting force, the better the effectiveness of hold-on. With increasing deviation angle, the deflecting force on the drill bit first decreases and then increases. The present model can provide a theoretical basis for wellbore trajectory control and optimization design of BHA.