Dynamic characteristics and test analysis of a new drilling downhole tool with anti-stick-slip features

Jia-lin Tian,Tangjia Zhang,Liming Dai,Wenming Cheng,Lin Yang,Chang-fu Yuan 대한기계학회 2018 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.32 No.10

A key problem in drill string dynamics is the stick–slip in deep and large displacement horizontal wells that may lead to the decline in drilling performance or cause tool failure, which may eventually cause underground accidents. Therefore, the research on the production safety, ROP, and increased efficiency in relation to stick–slip theory and practical stick–slip reduction is highly relevant, especially in complex drilling conditions. On this basis, this study takes the new constant torque tool as the engineering background and establishes the working mechanism analytical model of stick–slip reduction and torque constant. A helical dynamic model is established to solve the core problem of the constant torque tool. Then, the differential equation of the helical spline drive motion is deduced. The motion of the helical spline mandrel is calculated, and its analytical results are compared with simulation results. Findings show that the laws of angular displacement, angular velocity, axial displacement, and axial velocity are consistent with the simulation results when the helical spline mandrel moves up or down. The established theoretical model can promote the development of drill string dynamics in new drilling conditions. Moreover, the proposed designing methods can provide new ideas for the development of a stick–slip reduction tool. The results can be further used as reference for key parameter determination and stick–slip reduction technology optimization.

Vibration analysis of new drill string system with hydro-oscillator in horizontal well

Jia-lin Tian,Zhi Yang,You Li,Lin Yang,Chun-ming Wu,Gang Liu,Chang-fu Yuan 대한기계학회 2016 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.30 No.6

With the growth of oil and gas resource demand, the hydro-oscillator is widely used to enhance the Rate of penetration (ROP) and improve the efficacy in drilling various wells. The vibration model is the key issue of dynamics analysis and optimization of downhole tools. For the vibration analysis of the new drill string system with hydro-oscillator in the horizontal well, based on the design of the new hydro-oscillator and its operation conditions, the kinematics expressions are presented. Combined with the vibration force calculation results of the hydro-oscillator, the dynamics model of the new drill string system is established. Furthermore, the important features of vibration frequency, displacement, velocity and acceleration are discussed in the numerical example calculation results. By comparing the results of the calculation and experiment test, we can verify the correctness of the analysis model. With the hydro-oscillator vibration effect, the static friction between the drill string and wellbore is changed to the dynamic friction, so it can result in a significant increase in run length. At the same time, the ROP can be enhanced with the vibration effect. Moreover, with the parameters’ adjustment according to the operation conditions, the analysis method and model can also provide references to the study of similar downhole tools dynamics or mechanical properties.

Rock-breaking analysis model of new drill bit with tornado-like bottomhole model

Jia-lin Tian,Chang-fu Yuan,Lin Yang,Chuan-hong Fu,Gang Liu,Zhi Yang,Chun-ming Wu 대한기계학회 2015 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.29 No.4

For improving the rock-breaking efficiency of oil and gas drill bits, a new drill bit is presented with tornado-like bottomhole model(named swirling cutting bit). The new drill bit cutter breaks rock with shocking and cutting effect during the drilling process, and theelements on largest ring cross the borehole center with high speed. It can effectively improve the center rock-breaking efficiency. Meanwhile,for all cutters on different rings breaking rock at the same time, it can optimize the rock-breaking volume of each element andimprove the bit service life. To analyze the interaction features between cutters and rock, the position equations are established by thecylindrical coordinates and complex movement principles, and then the velocity and acceleration equations can be obtained. Based on thenumerical example results, this paper analyzes the bottomhole model, the contact section, and the distribution features of velocities andaccelerations on different rings. By analyzing the acceleration results, we can study the failure mechanism of cutters. At the same time,lab experiments test the bottomhole model and rock-breaking features, and it verifies the accuracy of calculation method and equations. Moreover, the analysis method and models are also applicable to other types of bits or composite bits, and the inputting parameters needcorresponding adjustment for different type of bits.

Research and experimental analysis of drill string dynamics characteristics and stick-slip reduction mechanism

Jia-lin Tian,Lai Wei,Lin Yang,Liming Dai,Tangjia Zhang,He Liu 대한기계학회 2020 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.34 No.3

Stick-slip of the drill string, as one of the critical factors affecting drilling efficiency, has always been a hot topic for experts and scholars in related fields. Serious stickslip vibration affects the well construction efficiency, drilling cost and even lead to a downhole accident. Therefore, based on the current research, this paper takes a new type of composite vibration tool as the research object, studies the working mechanism of the tool and analyzes the effect of stick-slip reduction. After establishing the multi-degree-of-freedom torsional dynamics model, we obtained the results of torsional vibration dynamics by cases analysis based on working conditions and related mechanical parameters. In addition, the results of the examples, compared with the field experimental data, verify that the vibration shock generated by the new composite tool can effectively reduce the torque fluctuation range of the system, avoid the occurrence of stick-slip phenomenon, improve the ROP (rate of penetration), and make drilling process more stable. This paper can provide reference for the optimization and development of stick-slip technology in drilling engineering, and the theoretical methods can also be developed to study the dynamics of drill string.

Bioremediation of Coastal Saline-Alkali Marshy Soil by the Irrigation with Pulp & Paper Wastewater

LI Jia-liang,LU Zhao-hua,TIAN Jia-yi,WANG Lin,LI Peng-hui,XIAO Zhong-feng 대전대학교 환경문제연구소 2009 환경문제연구소 논문집 Vol.13 No.-

Based on the importance of coastal saline-alkali soil remediation in Yellow River Delta, China, the Cl-、Na+ transferring tendency in soil and the saline-alkali soil eco-remediation effects were researched by measuring soil Cl-、Na+ 、soluble salt、soil respire rate and dry biomass weight of reed, etc. periodically. The results shows: the concentration of irrigated soil Cl-、Na+ and soluble salt were decreased 57.7-70%、45.7-47.1% and 53.2-59.7%, respectively, and soil salt decreasing level were little influenced by the hydraulic load, inundation depth varies in some degree, but it was influenced by dry-wet alternative irrigating mode The concentration of soil total nitrogen、organic mass、microbial respire rate, and the reed biomass above ground were increased averagely to 2.17、1.20、1.46 and 1.34 multiple respectively afterirrigation with wastewater, which have complex remediation effects on the coastal saline-alkali wetland, but there are some differences among the different irrigating crafts.

Thermal study of a scanning beam in granular flow target

Lin Ping,Qin Yuanshuai,Hao Changwei,Tian Yuan,Wan Jiangfeng,Jia Huan,Yang Lei,Duan Wenshan,Cai Han-Jie,Zhang Sheng 한국원자력학회 2022 Nuclear Engineering and Technology Vol.54 No.11

The concept of dense granular-flow target (DGT) for the China Initiative Accelerator Driven Subcritical system (CiADS) is an attractive choice for high heat removal ability, low chemical toxicity, and radiotoxicity. A wobbling hollow beam is proposed to enhance the homogeneity of temperature rise of flowing particles in beam-target coupling zone. In this paper, the design procedure of target and beam parameters was discussed firstly. Then we simulated the heat deposition and transfer of the scanning beam in DGT to study the effect of beam parameters. The results show the flux density of proton beam plays a crucial role in the distribution of temperature rise while the contributions from scanning frequency heat transfer are also obvious. Moreover, heat transfer in transversal directions is insignificant, resulting in a low heat flux towards the sidewalls of DGT. This work not only contributes to the design of DGT, but also beneficial for understanding the beam-target coupling in porous materials

The multidirectional vibration and coupling dynamics of drill string and its influence on the wellbore trajectory

Lin Yang,Jia-lin Tian,Qingyou Liu,Liming Dai,Zhichao Hu,Jurui Li 대한기계학회 2020 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.34 No.7

For improving the accuracy of wellbore trajectory prediction in complex wellbore structures, especially in the kick-off section, a longitudinal, torsional and radial coupled drill string dynamics model is proposed. At the same time, the coupling dynamics model is solved based on the energy method, and the torque, weight on bit (WOB), the longitudinal displacement and velocity, the torsional angular displacement and angular velocity of the drill bit are obtained during the normal drilling and the stick-slip vibration phase. Combining the numerical example and experimental test, the differences between different models and actual drilling trajectories are compared and analyzed. The research results indicate that the torsional vibration and the longitudinal vibration have a great influence on each other in the coupling model, and the longitudinal vibration displacement increases, which can effectively reduce the torque variation range of the torsional vibration. The operation of the bit stagnation is weakened, maintaining a relatively stable rotational angular velocity of rotation. The calculation results of the wellbore trajectory are more consistent with the experimental results, and can accurately reflect the real situation of the drilling process. The theoretical model has an important reference for predicting the new well structure, especially the judgment of wellbore trajectory of complex wellbore structures such as extended reach wells, horizontal wells, deep wells and high deep wells of coalbed methane, and the prediction of downhole dynamics results.

A Design of Mid-wave Infrared Integral Catadioptric Optical System with Wide FOV

Lin yao Yu,Hong guang Jia,Qun Wei,Hu hai Jiang,Tian yi Zhang,Chao Wang 한국광학회 2013 Current Optics and Photonics Vol.17 No.2

In order to deduce the difficulty of fixing the Ritchey-Chretien (R-C) dual reflective optical system and enhance the stability of the secondary mirror, a compact integral structure is presented here composed of two transmitting and two reflective aspheric surfaces. The four surfaces were manufactured from a single germanium lens and integrated together. The two reflective surfaces formed by coating the inner reflecting films were assembled in one lens. It makes the installation of the two mirrors easier and the structure of the secondary mirror more stable. A design of mid-wave infrared (MWIR) compact imaging system is presented with a spectral range chosen as 3.7-4.8 μm. The effective focal length is f=90 mm. The field of view (FOV) for the lens is 4.88°. It has good imaging capability with Modulation Transfer Function (MTF) of all field of view more than 0.55 close to the diffraction limitation. Outdoor experiments were carried out and it is shown that the integral catadioptric optical system performs well on imaging.

Bioremediation of Coastal Saline-Alkali Marshy Soil by the Irrigation with Pulp & Paper Wastewater

LI Jia-liang,LU Zhao-hua,TIAN Jia-yi,WANG Lin,LI Peng-hui,XIAO Zhong-feng 대전대학교 환경문제연구소 2009 환경문제연구소 논문집 Vol.13 No.-

Based on the importance of coastal saline-alkali soil remediation in Yellow River Delta, China, the Cl^-、Na⁺ transferring tendency in soil and the saline-alkali soil eco-remediation effects were researched by measuring soil Cl^-、Na⁺ 、soluble salt、 soil respire rate and dry biomass weight of reed, etc. periodically. The results shows: the concentration of irrigated soil Cl^-、Na⁺ and soluble salt were decreased 57.7-70%、45.7-47.1% and 53.2-59.7%, respectively, and soil salt decreasing level were little influenced by the hydraulic load, inundation depth varies in some degree, but it was influenced by dry-wet alternative irrigating mode The concentration of soil total nitrogen、organic mass、microbial respire rate, and the reed biomass above ground were increased averagely to 2.17、1.20、1.46 and 1.34 multiple respectively afterirrigation with wastewater, which have complex remediation effects on the coastal saline-alkali wetland, but there are some differences among the different irrigating crafts.

Distinctions Between Clinicopathological Factors and Prognosis of Alpha-fetoprotein Negative and Positive Hepatocelluar Carcinoma Patients

Xu, Jia,Liu, Chang,Zhou, Lei,Tian, Feng,Tai, Ming-Hui,Wei, Ji-Chao,Qu, Kai,Meng, Fan-Di,Zhang, Ling-Qiang,Wang, Zhi-Xin,Zhang, Jing-Yao,Chang, Hu-Lin,Liu, Si-Nan,Xu, Xin-Shen,Song, Yan-Zhou,Liu, Jun,Z Asian Pacific Journal of Cancer Prevention 2012 Asian Pacific journal of cancer prevention Vol.13 No.2

Serum alpha-fetoprotein (AFP) is a significant marker for clinical diagnosis and prognosis evaluation in hepatocellular carcinoma (HCC) patients. However, some proportion of liver cancer patients are AFP-negative (AFP ${\leq}$20ng/ml). In order to study the differences between clinicopathological factors and prognosis of alpha-fetoprotein negative and positive patients, a total of 114 cases (41 AFP-negative and 73 AFP-positive) were selected for our research. By systematically statistical analysis, the results demonstrated that compared with AFP-negative patients, AFP-positive examples were more likely to feature cirrhosis nodules, non-complete neoplasm capsules, and a poor Edmondson-steiner grade. Furthermore, AFP-negative patients demonstrated a favorable long-term prognosis. By univariate analysis and multivariate analysis with Cox's proportional hazards model, multiple tumors were found to be independent risk factors for worse survival of AFP negative patients; however, less tumor-free margins, multiple tumors and Edmondson-steiner grades III/IV, proved to be independent risk factors leading to a poor prognosis of AFP positive cases. Finally, we can infer that high levels of AFP signify a highly malignant tumor and unfavorable prognosis.