scholarly journals Structure Optimization of Rib Drill Pipe Based on Gas-Solid Coupling and Orthogonal Experiment

2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Jia Li ◽  
Dongmin Li ◽  
Peisi Zhong ◽  
Guofang Ma ◽  
Hengxuan Luan ◽  
...  

At present, drilling rig is a common equipment for controlling gas outburst generated in underground coal mine, and rib drill pipe is an important component of drilling rig. Due to the insufficiency of slag discharge capacity, pipe-sticking accidents often occur during the drilling process, which greatly reduces the effect of gas control. In order to improve the capacity of slag discharge of rib drill pipe, the mechanism of slag removal was analyzed, and the process of slag discharge was simulated as a gas-solid two-phase flow coupling process. Utilizing the computational fluid dynamics method, the process of slag discharge was simulated on the Edem-Fluent cosimulation platform. The structural parameters of the drill pipe affecting the capacity of slag discharge were derived. Based on the analysis results, the structural parameters of rib drill pipe were optimized by orthogonal experiment method. The global optimal results were obtained as follows: its pitch, blade height, and blade width are 120 mm, 3 mm, and 15 mm, respectively. Therefore, the results of slag discharge experiment on the optimum structure of rig drill pipe show that the slag discharge efficiency is increased by 11.38%, which effectively resolves the pipe-sticking problem.

2014 ◽  
Vol 945-949 ◽  
pp. 2601-2605 ◽  
Author(s):  
Zheng Qing Jiang ◽  
Bin Bin Wang ◽  
Huai Rong Dong ◽  
Qing Bao An

Sea or land rig requires a lot of roots in the drilling process. The catwalk-machine generally transports drill pipe to the second floor units. The rooted is established by dynamic rat holes, stored in boxes and taken from the rooted box during the drilling process. Automatic control systems for the rig on the stand of emissions complete automatic access of rooted. Previous control systems adopt the method of fixed access in order to complete the order for reducing control, although such control program is simple but the production efficiency is not high. In this paper, to access the walking path [1] in the process of the minimum as the optimization goal, not to block the internal root deposit box for qualification, designed a control algorithm to optimize the access path, which greatly improves access efficiency, reducing the distance of sports equipment, with high practical value.


2021 ◽  
Vol 271 ◽  
pp. 01004
Author(s):  
Weizheng Wu

Due to the low firmness coefficient of soft coal seam and the influence of formation pressure and in-situ stress, it is easy to cause hole collapse in bedding drilling, resulting in low hole forming rate and insufficient hole forming depth, so the drilling technology needs to be improved. This paper focuses on the study of hole forming technology and parameters of bedding drilling in soft coal seam. The research results show that: the key to improve the construction efficiency of bedding drilling in soft coal seam is to improve the slag removal ability of drilling engineering, and the drilling technology of spiral drilling and pressure air slag removal is conducive to improve the drilling depth and drilling effect. The hole forming process and parameters of spiral drilling and pressure air slag removal are systematically described. The drill pipe speed, the coal conveying capacity in the hole, the minimum wind speed of pressure air slag removal and the air supply pressure of slag removal are determined. It is of great practical significance to develop and improve the drilling technology of bedding hole drilling in soft coal seam to improve the gas drainage capacity of coal mine and the drilling depth and rate of bedding hole drilling in soft coal seam.


Author(s):  
S. М. Akhmetov ◽  
M. Diarov ◽  
N. М. Akhmetov ◽  
D. T. Bizhanov ◽  
Zh. K. Zaidemova

Heavy weight drill pipe (HWDP) in wells are hollow, weighty rods with stepwise changing physical properties (for example, stiffness), and each link of the string can deform according to geometrically nonlinear laws. They are the most critical part in the drilling process, transmitting power from the drilling rig to the rock failing tool, and are in hydrodynamic and contact interaction with the borehole walls, and are always curved. This occurs due to the curvature of the well itself, and under the action of its own weight, contact forces, as well as centrifugal forces in the case of rotation of the pipe. In this case, the curvature of the HWDP axis can be significantly influenced by the geometric nonlinearity of the deformation of its pipes. A review of this issue revealed a number of poorly studied problems, which include accounting for both phy- sically and geometrically nonlinear problems, accompanied by various types of complications (loss of stability HDWP, pipe breaks, etc.), as well as other processes in the elements of a dynamic drilling system (DDS). In this paper, based on the use of modern methods for studying dynamic processes in mechanical systems, a method is proposed for studying longitudinal oscillations of a geometrically nonlinear HWDP of its stability under torsion, taking into account the physical nonlinearity in the process of its deformation. The dependences characte- rizing this process are found.


2020 ◽  
Vol 20 (3) ◽  
pp. 975-995
Author(s):  
Jianwei Wang ◽  
Shixuan Wang ◽  
Haoyu Le ◽  
Maoxin Ge

To reduce the failure probability of gas drainage drilling holes in coal mines, a new modeling method of gas drainage drilling machine is presented. Firstly, each drill pipe is regarded as a flexible body, and the Lagrange’s equation of second kind is used to model it. Secondly, the joint of drill bit, hole wall and drill pipe are regarded as rigid bodies, and the Newton-Euler method is used to model it. Thirdly, the rigid-flexible coupling multi-body dynamic model of drilling rig-drill pipe-hole wall system in medium and short horizontal section of soft coal seam is established by using relative node coordinate method, and the time complexity and operation complexity of modeling are reduced by using ADAMS macro program. Finally, the finite element method is used to discretize the model, and the virtual prototyping technology is used to solve the mathematical model. The simulation results show that the coupling of friction and vibration does not necessarily increase the probability of drilling failure, but sometimes reduces the amplitude of vibration. Compared with the length of each drill pipe, the influence of drilling depth on the system is greater, and the bit-bounce behaviours is more likely to occur in the deep hole. The operating frequency range of the drilling rig is 6.9E-3 to 2.1E+4Hz. When the length of the drill pipe is constant, the natural frequency of the system increases with the increase of the order, while the natural frequency of the deep hole section is almost unaffected by the order. In practical engineering, the vibration excitation of the actuator should be controlled to avoid the natural frequency. Meanwhile, the modal frequency should be avoided as far as possible to reduce the vibration and the failure probability of drilling holes. The model can simulate a series of dynamic responses of drilling rig system in drilling process, and provide theoretical support for subsequent multi-factor coupling modeling.


1981 ◽  
Vol 46 (7) ◽  
pp. 1675-1681 ◽  
Author(s):  
Josef Baldrian ◽  
Božena N. Kolarz ◽  
Henrik Galina

Porosity variations induced by swelling agent exchange were studied in a styrene-divinylbenzene copolymer. Standard methods were used in the characterization of copolymer porosity in the dry state and the results were compared with related structural parameters derived from small angle X-ray scattering (SAXS) measurements as developed for the characterization of two-phase systems. The SAXS method was also used for porosity determination in swollen samples. The differences in the porosity of dry samples were found to be an effect of the drying process, while in the swollen state the sample swells and deswells isotropically.


Author(s):  
E.V. Legostaeva ◽  
◽  
M.A. Khimich ◽  
Yu.P. Sharkeev ◽  
A.Yu. Eroshenko ◽  
...  

The effect of heat treatment of the Ti-45Nb alloy in the UFG state on its structural parameters (lattice parameters, volumetric phase ratio, sizes of coherent scattering regions, residual normal stresses) and their relationship with heat capacity have been studied. It has been established that the different character of the temperature dependence of the heat capacity for the Ti-45Nb alloy in the UFG and CC states is associated with the structural-phase features of the alloy in the UFG state: the two-phase structure of a-grains and b-grains, dispersion-hardened by the ω-phase, and phase transitions in the temperature range 400-600 °С.


Author(s):  
Deepanjan Mitra ◽  
Vijay K. Dhir ◽  
Ivan Catton

In the past, fluid-elastic instability in two-phase flow has been largely investigated with air-water flow. In this work, new experiments are conducted in air-water cross-flow with a fully flexible 5 × 3 normal square array having pitch-to-diameter ratio of 1.4. The tubes have a diameter of 0.016 m and a length of 0.21 m. The vibrations are measured using strain gages installed on piano wires used to suspend the tubes. Experiments are carried out for void fractions from 0%–30%. A comparison of the results of the current tests with previous experiments conducted in air-water cross-flow shows that instability occurs earlier in a fully flexible array as compared to a flexible tube surrounded by rigid tubes in an array. An attempt is made to separate out the effects of structural parameters of three different experimental datasets by replotting the instability criterion by incorporating the instability constant K, in the reduced velocity parameter.


Author(s):  
Magnus Nystad ◽  
Bernt Aadnoy ◽  
Alexey Pavlov

Abstract The Rate of Penetration (ROP) is one of the key parameters related to the efficiency of the drilling process. Within the confines of operational limits, the drilling parameters affecting the ROP should be optimized to drill more efficiently and safely, to reduce the overall cost of constructing the well. In this study, a data-driven optimization method called Extremum Seeking (ES) is employed to automatically find and maintain the optimal Weight on Bit (WOB) which maximizes the ROP. The ES algorithm is a model-free method which gathers information about the current downhole conditions by automatically performing small tests with the WOB and executing optimization actions based on the test results. In this paper, this optimization method is augmented with a combination of a predictive and a reactive constraint handling technique to adhere to operational limitations. These methods of constraint handling within ES application to drilling are demonstrated for a maximal limit imposed on the surface torque, but the methods are generic and can be applied on various drilling parameters. The proposed optimization scheme has been tested with experiments on a downscaled drilling rig and simulations on a high-fidelity drilling simulator of a full-scale drilling operation. The experiments and simulations show the method's ability to steer the system to the optimum and to handle constraints and noisy data, resulting in safe and efficient drilling at high ROP.


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