Study on the mechanism of drilling speed increase considering the axial vibration of drill string

It is a hot topic for deep/ultradeep wells to improve rock-breaking efficiency and drilling speed by available downhole energy. Based on different downhole energies and working conditions, specialized plunger pump is proposed to convert longitudinal vibration of drilling string into rock-breaking energy. Technical design is developed to generate high-pressure water jet. And then a simulation model is built to verify feasibility of the technical design. Through simulation, the influence law of key factors is obtained. On this basis, this device is tested in several wells. The result indicates this device can increase drilling speed as much as 136%. Meanwhile the harmful vibration can be absorbed. The energy from drilling string vibration is of high frequency and increases as well depth and formation anisotropy increase. By reducing adverse vibration, this device is able to increase the drilling speed and the service life also meets the demand of field application. The longest working time lasts for more than 130 hours. The performance of this device demonstrates great application prospect in deep/ultradeep resources exploration. To provide more equipment support for deep/ultradeep wells, more effort should be put into fundamental study on downhole drill string vibration and related equipment.

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Sonic Drilling with Use of a Cavitation Hydraulic Vibrator

10.5772/intechopen.100336 ◽

2021 ◽

Author(s):

Yuriy Zhulay ◽

Olexiy Nikolayev

Keyword(s):

Drill String ◽

Drill Bit ◽

Vibration Frequencies ◽

Drilling Speed ◽

Temporary Reduction ◽

Inertia Effects ◽

Hard Rocks ◽

Mud Pressure ◽

State Pressure ◽

Mud Flow

Sonic drilling is a soil penetration technique that strongly reduces friction on the drill string and drill bit due to liquefaction, inertia effects and a temporary reduction of porosity of the soil. Modern studies to assess the effect of the vibration frequency of the drill bit on the rock fragmentation in experimental and theoretical works on drilling various rocks by the sonic method have shown that vibration frequencies of ~ 1.4 kHz are the most beneficial for ensuring the maximum drilling speed in hard rocks. The above frequencies of excitation of vibrations of the drill bit can be achieved by using a cavitation hydrovibrator. The cavitation hydrovibrator is the Venturi tube of special geometry that converts a stationary fluid (flushing mud) flow into an oscillatory stalling cavitation flow and hydrovibrator structure longitudinal vibrations. The drill bit vibration accelerations are realized in such a drill string, leading to the destruction of rock. Efficient removal of rock particles from the bottomhole is achieved due to high-frequency shock self-oscillations of mud pressure exceeding the steady-state pressure at the generator inlet. The cavitation hydraulic vibrator lacks the main disadvantages of submersible hydraulic hammers.

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Arithmetic solution for the axial vibration of drill string coupling with a down-the-hole hammer in rock drilling

Journal of Vibration and Control ◽

10.1177/1077546314560041 ◽

2014 ◽

Vol 22 (13) ◽

pp. 3090-3101 ◽

Cited By ~ 3

Author(s):

Changgen Bu ◽

Xiaofeng Li ◽

Long Sun ◽

Boru Xia

Keyword(s):

Drill String ◽

Axial Vibration ◽

Rock Drilling

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Effect of Axial Vibration on Sliding Frictional Force between Shale and 45 Steel

Shock and Vibration ◽

10.1155/2018/4179312 ◽

2018 ◽

Vol 2018 ◽

pp. 1-13 ◽

Cited By ~ 2

Author(s):

Wu Hao ◽

Chen Ping ◽

Liu Yang ◽

Ma Tianshou

Keyword(s):

Friction Coefficient ◽

Friction Force ◽

Sliding Friction ◽

Complex Structure ◽

Drill String ◽

Friction Reduction ◽

Vibration Velocity ◽

Model Parameters ◽

Axial Vibration ◽

Friction Reducing

Activating drill string vibration is an effective means to mitigate the excessive drag encountered during drilling complex-structure wells. However, the Coulomb model cannot describe the sliding friction behavior between drill string and borehole rock with imposed axial vibrations. To solve this problem, a specially designed experimental setup was utilized to investigate the characteristics of axial vibrating-sliding coupling friction. The results indicate that when vibration velocity is greater than sliding velocity, axial vibration can significantly reduce friction force between contact surfaces. Its friction reduction mechanism embodies not only the changes of instantaneous friction force, but also friction coefficient. Meanwhile, a friction coupling model was established based on the Hertz contact theory and Dahl model. The corresponding computational program was developed in Matlab/Simulink environment. The calculation results are in good agreement with the experimental results, verifying the validity of the present method. Furthermore, to overcome the shortcoming of Dahl model, a dynamic friction coefficient model was proposed to evaluate the friction-reducing effect of axial vibration using dimensional analysis method. The model parameters under different lubrication conditions were retrieved through inverse calculation with experimental data. This method provides a new solution for evaluating the friction-reducing effect of hydraulic oscillator and optimizing its placement.

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Progress and development of particle jet drilling speed-increasing technology and rock-breaking mechanism for deep well

Journal of Petroleum Exploration and Production Technology ◽

10.1007/s13202-021-01443-4 ◽

2021 ◽

Author(s):

Tiancheng Fang ◽

Fushen Ren ◽

Hanxu Liu ◽

Yuan Zhang ◽

Jianxun Cheng

Keyword(s):

Constitutive Model ◽

High Efficiency ◽

Rock Breaking ◽

Drilling Speed ◽

Speed Increase ◽

Deep Well ◽

Jet Impact ◽

Drilling Technology ◽

Breaking Mechanism ◽

Hard Formation

AbstractIncreasing drilling speed and efficiency of hard formation for deep and ultra-deep well is one of the international recognized drilling problems and key technologies to be tackled urgently. Particle jet impact drilling technology is an efficient non-contact rock-breaking method to overcome slow drilling speed, which has great development and application potential in drilling speed-increase of hard formation and deep well. High efficiency drilling technology and rock-breaking speed-increase mechanism in high temperature, high pressure and high hardness formations of deep and ultra-deep wells were mainly focused and keynoted in this paper. With extensive investigation of domestic and foreign literature, the working principle, key technical devices, deep-well-rock mechanical characteristic, unconventional constitutive model and rock-breaking mechanism of particle jet impact drilling technology were analyzed, which proved the feasibility and high efficiency for deep and hard stratum, and also, dynamic failure mechanism of rock needs to be elaborated by constructing the constitutive model with high temperature and pressure. Meanwhile, the major problems to be solved at present and development direction future were summarized, which mainly included: miniaturization of drilling equipment and individualization of drilling bit; optimization of jet parameters and the evaluation method of rock-breaking effect; establishment of mechanical property and unconventional constitutive model of deep-well-rock; rock-breaking mechanism and dynamic response under particle jet coupling impact. The research can help for better understanding of deep-well drilling speed-increasing technology and also promote the development and engineering application of particle jet impact drilling speed-increase theory and equipment.

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INFLUENCE OF DRILLING RIG DESIGN ON WELL DRILLING EFFICIENCY

Sustainable Development of Mountain Territories ◽

10.21177/1998-4502-2020-12-3-383-393 ◽

2020 ◽

Vol 12 (3) ◽

pp. 383-393

Author(s):

Vasily ANISCHENKO ◽

◽

Viktor ATRUSHKEVICH ◽

Keyword(s):

Average Length ◽

Drill Pipe ◽

Hydraulic Drive ◽

Drill String ◽

Alternative Methods ◽

Drilling Speed ◽

Directional Drilling ◽

Horizontal Section ◽

Main Research ◽

Drilling Rig

The purpose of research in the extraction of minerals is the development of technologies that will make it possible to drill wells specially designed for the extraction of ores with a length of several kilometers and a diameter of 300 mm to 2 m. The main research method is an experiment, during which drilling of wells by alternative methods under the same conditions is compared according to a single the selected performance criterion. Drilling of wells with an average length of 1500 meters with an end diameter of 295 mm at a depth of 200 to 400 meters was carried out in soft rocky ground in two alternative ways. The productivity of a directional drilling rig is determined by the efficiency of related interconnected processes,the correlation of which is characterized by graphs, for example, the dependence of the load on the bit on the drilling speed. To calculate the load on the drill pipe, Young’s modulus and the moment of inertia of its section were used. The axial force for drilling the well is determined by calculation using experimental data. By modeling in the EXCEL program, the maximum WOB value was determined. To compare the drilling speeds of a traditional rig and a new generation rig, the speed with a 5 ton bit load and a 15 ton bit load is considered, at which, if other things are equal,the ROP increases three times. The drilling speed of wells with an inclined head of the new technology will be 167 m per day versus 105 m with traditional technology, and the operational productivity of drilling with one rig will be 71 m per day versus 51 m. Universal mobile rack rigs with automatic centering of the drill string and mast in vertical and inclined position and gearless hydraulic drive for rotation and movement of the drilling carriage ensure drilling of wells with a horizontal section length of 1500 meters and a diameter of 300 mm.

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