scholarly journals Development and Application of the Downhole Drilling String Shock-Absorption and Hydraulic Supercharging Device

2016 ◽  
Vol 2016 ◽  
pp. 1-10 ◽  
Author(s):  
Yongwang Liu ◽  
Zhichuan Guan ◽  
Hongning Zhang ◽  
Bo Zhang
Keyword(s):  
Longitudinal Vibration ◽  
Rock Breaking ◽  
Drill String ◽  
Field Application ◽  
Drilling Speed ◽  
Technical Design ◽  
Fundamental Study ◽  
String Vibration ◽  
Drilling String ◽  
Breaking Energy

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.

scholarly journals The rock breaking capability analyses of sonic drilling

2021 ◽  
pp. 146134842110251
Author(s):  
Yonghang Qian ◽  
Yu Wang ◽  
Zhiqiao Wang ◽  
Bairu Xia ◽  
Liya Liu
Keyword(s):  
Longitudinal Vibration ◽  
Rock Breaking ◽  
Drill String ◽  
Energy Utilization ◽  
Utilization Rate ◽  
Drilling Process ◽  
Percussive Drilling ◽  
Drilling Depth ◽  
Maximum Impact Force ◽  
Breaking Energy

Sonic drilling technology uses the longitudinal vibration of a drill string to realize fast and effective drilling. By setting the top and bottom boundary conditions of the drill string during drilling, a dynamic model of flexible sonic string percussive drilling is established in this article. At a certain drilling depth, with the excitation frequencies as the control parameters, the maximum impact force and rock breaking energy utilization rate are used to evaluate the rock breaking capability of the sonic drilling system under the linear bit–rock model. A surface diagram of the maximum breaking force reached within the working frequencies and at varying drilling depths is obtained. The curve graph of the rock breaking energy utilization rate varying with drilling depth under the first six orders of resonance is also calculated. Analysing the influence of changing drilling parameters on the rock breaking capability of sonic drilling systems can provide theoretical guidance for the actual drilling process.

scholarly journals Chaotic Vibration Analysis of the Bottom Rotating Drill String

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Qilong Xue ◽  
Ruihe Wang ◽  
Feng Sun ◽  
Zhiyuan Huang
Keyword(s):  
Correlation Dimension ◽  
Chaotic Behavior ◽  
Longitudinal Vibration ◽  
Drill String ◽  
Largest Lyapunov Exponent ◽  
Potential Implication ◽  
Finite Time Lyapunov Exponents ◽  
String Vibration ◽  
Real Time Measurement ◽  
Vibration Time

Drill string vibration is a widely studied topic. This paper developed a real-time measurement system near the drilling bit and extracted the lateral vibration, longitudinal vibration time series of bottom rotating drill string. In order to reconstruct the phase space, we estimated the delay time with mutual information and calculated the embedding dimension through Cao’s method. Finally, the chaotic characterization of the system is analyzed by calculating the correlation dimension and the largest Lyapunov exponent. The results show that such system can exhibit positive finite-time Lyapunov exponents and a clear convergence toward the correlation dimension, which is a strong indicator for the chaotic behavior of the system. It is expected that the new dynamics found in this paper could be of potential implication to the control methods of the drill string vibration.

Drill String Vibration Attenuation and Its Effect on a Surface Oscillator Drilling System

1965 ◽  
Vol 87 (2) ◽  
pp. 110-114 ◽  
Author(s):  
F. A. Angona
Keyword(s):  
Fourier Analysis ◽  
Drill String ◽  
Acoustic Vibrations ◽  
String Vibration ◽  
Vibration Attenuation ◽  
Vibratory Motion ◽  
Drilling String ◽  
Drilling System ◽  
Relationship Of ◽  
The Relationship

The attenuation of acoustic vibrations was determined by measuring the decay of stress pulses induced in a drilling string. The relationship of attenuation to frequency was obtained by a Fourier analysis of the pulse after it had traveled various distances in the drill string. The attenuation coefficient was found to be sufficiently low to warrant consideration of drilling methods in which vibratory motion is transmitted from a surface vibrator to the bit by the drill string.

scholarly journals Dynamic Characteristics of Downhole Bit Load and Analysis of Conversion Efficiency of Drill String Vibration Energy

Energies ◽  
2021 ◽  
Vol 14 (1) ◽  
pp. 229
Author(s):  
Yuqiang Xu ◽  
Hongning Zhang ◽  
Zhichuan Guan
Keyword(s):  
Energy Conversion ◽  
Conversion Efficiency ◽  
Rotation Rate ◽  
Longitudinal Vibration ◽  
Drill Pipe ◽  
Energy Conversion Efficiency ◽  
Elastic Stiffness ◽  
Positive Influence ◽  
Drill String ◽  
String Vibration

The longitudinal vibration of the drill pipe contains considerable energy which can be used to improve the rock-breaking efficiency during drilling. It is very important to the development of drilling speed-up tools to have a comprehensive understanding of the energy conversion efficiency of downhole drill string vibration. In this paper, the characteristics of downhole bit load and longitudinal vibration of drill string under different conditions were studied in the experiment, and the analysis method of energy conversion efficiency from drill string vibration to spring potential energy was proposed. The experimental analysis showed that the fluctuation of the downhole bit load was reduced by 10%–90% after the spring was installed in the bottom hole assembly. The rotation rate and the spring elastic stiffness had a significant and positive influence on the fluctuation amplitude of the downhole bit load. Meanwhile, the longitudinal vibration amplitude and acceleration of the drill string peaked at the elastic stiffness of 1 kN/mm. The closer the spring position to the drill bit was, the more severe the longitudinal vibration of the drill string above the spring component was. The bit load and the rotation rate had a positive influence on the severity of longitudinal vibration. The analysis of energy conversion efficiency showed that the available mechanical energy range of the longitudinal vibration of the drill pipe was about 200–420 kW. The work power of the drill string vibration to the spring component increased sharply and then decreased with the increasing of elastic stiffness. The energy conversion efficiency came to the optimal value when the elastic stiffness was between 1 kN/mm and 2 kN/mm. Increasing the rotation rate, keeping the bit load below 134.5 kN and installing the spring component near the drill bit are beneficial for improving the energy conversion efficiency of drill string vibration. This paper reveals the main factors affecting the energy conversion efficiency of drill string vibration and their influencing laws, and determines the range of WOB, rotation speed, spring position and stiffness to obtain the best energy conversion efficiency.

Drilling String Vibration: Modelling and Simulation

2018 ◽  
Author(s):  
Sergio Amat ◽  
Gustavo E. Henríquez Velez ◽  
María J. Legaz
Keyword(s):  
Global Economy ◽  
Drill String ◽  
Optimal Parameters ◽  
Offshore Structure ◽  
String Vibration ◽  
Drilling Performance ◽  
Drilling String ◽  
Drilling Operations ◽  
Offshore Industry ◽  
Crucial Part

The offshore industry has a significant impact on the global economy and it is expected to grow over the next 4 years. A crucial part of an offshore structure is the drill string. Drill strings can be seriously damaged by vibration during drilling operations. The control of vibrations in drill strings is essential. In drilling wells, this is useful to minimize the risks of well loss and also to improve drilling performance. The objective of this study is to model and simulate the vibrations in drill strings. This is made to know the region of stabilization of the system and to establish the optimal parameters of drilling which can be manipulated from the driller console, such as angular velocity of the drill string on the surface and the weight on the drill bit. The simulation of these vibrations is made by solving the differential equations that describe these phenomena. An interface for the manipulation of variables involved in the models of the drill string has been designed and shown in this work.

scholarly journals Simulation of impact load modulation device based on drill string vibration

2021 ◽  
Vol 2093 (1) ◽  
pp. 012001
Author(s):  
Xiaopeng Lu ◽  
Hualin Liao ◽  
Huajian Wang ◽  
Wenlong Niu ◽  
Jiansheng Liu
Keyword(s):  
Impact Load ◽  
Longitudinal Vibration ◽  
Rock Breaking ◽  
Drill String ◽  
Vibration Energy ◽  
Well Drilling ◽  
Deep Well ◽  
Load Modulation ◽  
Output Characteristics ◽  
The Impact

Abstract The longitudinal vibration of the bottom drill string is violent and the law is complex during the deep well drilling. The vibration of the drill string brings many adverse effects on the drilling pipe fracture and bit trampoling. Generally speaking, the effective way to control the vibration of drill string is to install damping device in bottom hole. The research group proposes a device that uses the longitudinal vibration energy of the deep well drill string to modulate the impact dynamic load, which converts the vibration energy of the downhole drill string that is not conducive to drilling into the mechanical impact energy that improves the rock breaking capacity of the bit. The impact load modulation device can use the drill string to apply the “mechanical WOB” and the differential pressure between the upper and lower piston to produce the “hydraulic WOB”, The simulation results show that the adjustable range of output load is 2 ~ 7T, and the change of each time is about 2T. The modulation law of impact load under the influence of longitudinal vibration of drill string and different parameters is analyzed. Through ground experiment and simulation, the damping performance and speed-up effect of the modulation device are compared and analyzed, and the impact load output characteristics of the device are analyzed, which provides a thinking for the design of damping and pressurization tools.

scholarly journals Prediction of shallow bit position based on vibration signal monitoring of bit broken rock

2021 ◽  
Vol 17 (1) ◽  
pp. 155014772199170
Author(s):  
Jinping Yu ◽  
Deyong Zou
Keyword(s):  
Acoustic Emission ◽  
Time Domain ◽  
Vibration Signal ◽  
Rock Breaking ◽  
Drill String ◽  
Mean Square ◽  
Drilling Force ◽  
Emission Signal ◽  
Force Signal ◽  
The Mean

The speed of drilling has a great relationship with the rock breaking efficiency of the bit. Based on the above background, the purpose of this article is to predict the position of shallow bit based on the vibration signal monitoring of bit broken rock. In this article, first, the mechanical research of drill string is carried out; the basic changes of the main mechanical parameters such as the axial force, torque, and bending moment of drill string are clarified; and the dynamic equilibrium equation theory of drill string system is analyzed. According to the similarity criterion, the corresponding relationship between drilling process parameters and laboratory test conditions is determined. Then, the position monitoring test system of the vibration bit is established. The acoustic emission signal and the drilling force signal of the different positions of the bit in the process of vibration rock breaking are collected synchronously by the acoustic emission sensor and the piezoelectric force sensor. Then, the denoised acoustic emission signal and drilling force signal are analyzed and processed. The mean value, variance, and mean square value of the signal are calculated in the time domain. The power spectrum of the signal is analyzed in the frequency domain. The signal is decomposed by wavelet in the time and frequency domains, and the wavelet energy coefficients of each frequency band are extracted. Through the wavelet energy coefficient calculated by the model, combined with the mean, variance, and mean square error of time-domain signal, the position of shallow buried bit can be analyzed and predicted. Finally, by fitting the results of indoor experiment and simulation experiment, it can be seen that the stress–strain curve of rock failure is basically the same, and the error is about 3.5%, which verifies the accuracy of the model.

Finite Element Analysis on Axial-Torsional Coupled Vibration of Drill String

2011 ◽  
Vol 291-294 ◽  
pp. 1952-1956 ◽  
Author(s):  
Xue Liang Bi ◽  
Jian Wang ◽  
Zhan Lin Wang ◽  
Shi Hui Sun
Keyword(s):  
Finite Element ◽  
Coupled Model ◽  
Resonance State ◽  
Drill String ◽  
Hole Drilling ◽  
Drilling Process ◽  
Coupled Vibration ◽  
Element Analysis ◽  
Drilling String ◽  
Rotary Speed

In the drilling process, axial vibration, transverse vibration and torsional vibration happen to drilling string. And the coupled vibration is more complex. In the resonance state, drilling string collides with the wall, which causes serious damage on drilling string in a short time and results in economic loss to the drilling operation. In this paper, the regularity of coupled vibration is analyzed by using finite element method. The model of full-hole drilling strings is established. The distribution regularities of coupled resonant frequency are obtained through computer analysis. The coupled model is more accurate than single vibration model. And the gaps of high rotary speed resonance regions are larger. Resonance state can be avoided by changing rotary speed, and drilling accidents can be reduced.

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