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.

Pipe stick problems of deep well drilling

2021 ◽  
Vol 66 (05) ◽  
pp. 192-195
Author(s):  
Rövşən Azər oğlu İsmayılov ◽  
Keyword(s):  
Drilling Fluid ◽  
Drill Pipe ◽  
Drill String ◽  
Differential Pressure ◽  
Drilling Mud ◽  
Fluid Circulation ◽  
Well Drilling ◽  
Deep Well ◽  
Pressure Pipe ◽  
Bottomhole Pressure

The aricle is about the pipe stick problems of deep well drilling. Pipe stick problem is one of the drilling problems. There are two types of pipe stick problems exist. One of them is differential pressure pipe sticking. Another one of them is mechanical pipe sticking. There are a lot of reasons for pipe stick problems. Indigators of differential pressure sticking are increase in torque and drug forces, inability to reciprocate drill string and uninterrupted drilling fluid circulation. Key words: pipe stick, mecanical pipe stick,difference of pressure, drill pipe, drilling mud, bottomhole pressure, formation pressure

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 Effects of axial impact load on the dynamics of an oilwell drillstring

2019 ◽  
Vol 11 (3) ◽  
pp. 168781401983687
Author(s):  
Liping Tang ◽  
Xiaohua Zhu ◽  
Hongzhi Lin
Keyword(s):  
Sensitivity Analysis ◽  
High Frequency ◽  
Impact Load ◽  
Drill String ◽  
Impact Loads ◽  
Harmonic Force ◽  
Cross Sectional ◽  
Axial Impact ◽  
Energy Conservation Method ◽  
The Impact

This article studies the dynamics of oilwell drillstring under large and small axial impact loads. For the case of large impact load, the drillstring is regarded as a continuous bar under the impact load of a falling mass, and the energy conservation method is implemented. A sensitivity analysis is conducted to investigate the effect of cross-sectional area of the drill string on the impact stress. Results show that the design of drillstring with different cross-sectional areas is not a suitable method. In order to understand the effect of high-frequency small axial impact (applied from percussion tools or downhole generators) on the drillstring vibration, a mechanical model in which the drillstring is regarded as a 2-degree-of-freedom system under a harmonic force is developed. Sensitivity analysis on the effects of impact generator placement and impact frequency on drillstring dynamics are conducted. Results show that the impact generator should be installed near the drill bit and that high frequency is recommended to be used.

scholarly journals Propagation of Measurement-While-Drilling Mud Pulse during High Temperature Deep Well Drilling Operations

2013 ◽  
Vol 2013 ◽  
pp. 1-12 ◽  
Author(s):  
Hongtao Li ◽  
Yingfeng Meng ◽  
Gao Li ◽  
Na Wei ◽  
Jiajie Liu ◽  
...  
Keyword(s):  
High Temperature ◽  
Angular Frequency ◽  
Drill String ◽  
Linear Perturbation ◽  
State Equations ◽  
Attenuation Coefficients ◽  
Well Drilling ◽  
Deep Well ◽  
Measurement While Drilling ◽  
Density Behavior

Signal attenuates while Measurement-While-Drilling (MWD) mud pulse is transmited in drill string during high temperature deep well drilling. In this work, an analytical model for the propagation of mud pulse was presented. The model consists of continuity, momentum, and state equations with analytical solutions based on the linear perturbation analysis. The model can predict the wave speed and attenuation coefficient of mud pulse. The calculated results were compared with the experimental data showing a good agreement. Effects of the angular frequency, static velocity, mud viscosity, and mud density behavior on speed and attenuation coefficients were included in this paper. Simulated results indicate that the effects of angular frequency, static velocity, and mud viscosity are important, and lower frequency, viscosity, and static velocity benefit the transmission of mud pulse. Influenced by density behavior, the speed and attenuation coefficients in drill string are seen to have different values with respect to well depth. For different circulation times, the profiles of speed and attenuation coefficients behave distinctly different especially in lower section. In general, the effects of variables above on speed are seen to be small in comparison.

scholarly journals The effect of high-frequency torsional impacts on the dynamic response of a drill string in a stick state

2019 ◽  
Vol 11 (3) ◽  
pp. 168781401982857
Author(s):  
Liping Tang ◽  
Wei He ◽  
Xiaohua Zhu
Keyword(s):  
Dynamic Response ◽  
High Frequency ◽  
Impact Load ◽  
Drill String ◽  
Superposition Method ◽  
Drill Bit ◽  
Stick Slip ◽  
Mode Superposition Method ◽  
Study Results ◽  
The Impact

Stick–slip vibration is common in the oil well drilling process and is detrimental to down-hole equipment and drilling efficiency. In recent years, a new type of drilling technology, torsional impact drilling, has been developed to mitigate the stick–slip phenomena, particularly in the drilling of deep or abrasive formations. With this drilling technique, high-frequency torsional impacts are generated and applied to the drill bit, providing the drill bit with auxiliary energy. By mitigating or suppressing the stick–slip vibration, part of the energy wasted as a result of vibration can be regained. However, the effect of these impact loads on the dynamic response of a drill string in a stick state is unknown. In order to address this issue, a continuous system model of a drill string that includes torsional impact load was constructed. In the model, a Fourier series approach was used for the impact load, and the mechanical model was resolved with the mode superposition method. Case studies were done to understand the drill string dynamics, with and without the impact. The case study results demonstrate that high-frequency torsional impacts have little influence on the dynamic response of a drill string in a stick state.

Numerical simulation of rock-breaking under the impact load of self-excited oscillating pulsed waterjet

2020 ◽  
Vol 96 ◽  
pp. 103179 ◽  
Author(s):  
Hongsheng Li ◽  
Songyong Liu ◽  
Jiguang Jia ◽  
Fengchao Wang ◽  
Chuwen Guo
Keyword(s):  
Numerical Simulation ◽  
Impact Load ◽  
Rock Breaking ◽  
The Impact ◽  
Pulsed Waterjet

Application Research on Low-Pressure Pulse and Cavitation Jet Compound Drilling Technology

2011 ◽  
Vol 137 ◽  
pp. 205-209 ◽  
Author(s):  
Wen Fei Li ◽  
Guang Lei Wang
Keyword(s):  
Pressure Pulse ◽  
Breaking Strength ◽  
Low Pressure ◽  
Rock Breaking ◽  
Strength Increase ◽  
Application Research ◽  
Hydraulic Power ◽  
Well Drilling ◽  
Deep Well ◽  
Drilling Technology

In the low-pressure pulse and cavitation jet compound drilling technology, pulse low-pressure and cavitation jet generator is installed on bit, water jet modulated by generator can generate pulse low-pressure, which will alternate rock mechanics, decrease rock breaking strength, increase rock-breaking efficiency. And cavitation jet generated can increase hydraulic power downhole. The results show that low-pressure pulse and cavitation jet generator has been run well from 5349m to 6162m for 129.36h-136.63h in TK1090 well, increasing drilling speed 40.6%～85.1%. The low-pressure pulse and cavitation jet compound drilling technology can increase drill speed and be deployment in deep well drilling.

Impact Load Buffering Method Based on Stress Wave Attenuation Principle

2019 ◽  
Vol 11 (02) ◽  
pp. 1950019 ◽  
Author(s):  
Lin Gan ◽  
He Zhang ◽  
Cheng Zhou ◽  
Lin Liu
Keyword(s):  
Stress Wave ◽  
Wave Attenuation ◽  
Impact Load ◽  
Dynamics Simulation ◽  
Scanning System ◽  
Isolation Method ◽  
Element Analysis ◽  
System A ◽  
High Emission ◽  
The Impact

Rotating scanning motor is the important component of synchronous scanning laser fuze. High emission overload environment in the conventional ammunition has a serious impact on the reliability of the motor. Based on the theory that the buffer pad can attenuate the impact stress wave, a new motor buffering Isolation Method is proposed. The dynamical model of the new buffering isolation structure is established by ANSYS infinite element analysis software to do the nonlinear impact dynamics simulation of rotating scanning motor. The effectiveness of Buffering Isolation using different materials is comparatively analyzed. Finally, the Macht hammer impact experiment is done, the results show that in the experience of the 70,000[Formula: see text]g impact acceleration, the new buffering Isolation method can reduce the impact load about 15 times, which can effectively alleviate the plastic deformation of rotational scanning motor and improve the reliability of synchronization scanning system. A new method and theoretical basis of anti-high overload research for Laser Fuze is presented.

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