scholarly journals Experimental Study on Axial Impact Mitigating Stick-Slip Vibration with a PDC Bit

2021 ◽  
Vol 2021 ◽  
pp. 1-8
Author(s):  
Yong Wang ◽  
Hongjian Ni ◽  
Yiliu (Paul) Tu ◽  
Ruihe Wang ◽  
Xueying Wang ◽  
...  
Keyword(s):  
Impact Force ◽  
Impact Load ◽  
Similarity Theory ◽  
Impact Frequency ◽  
Stick Slip ◽  
Axial Impact ◽  
Pdc Bit ◽  
Fluctuation Amplitude ◽  
Rotary Speed ◽  
The Impact

Stick-slip vibration reduces the drilling rate of penetration, causes early wear of bits, and threatens the safety of downhole tools. Therefore, it is necessary to study suppression methods of stick-slip vibration to achieve efficient and safe drilling. Field tests show that the use of downhole axial impactors is helpful to mitigate stick-slip vibration and improve rock-breaking efficiency. However, there are many deficiencies in the study of how axial impact load affects stick-slip vibration of a PDC bit. In this paper, based on the two-degrees-of-freedom spring-mass-damper model and similarity theory, a laboratory experiment device for suppressing stick-slip vibration of a PDC bit under axial impact load has been developed, and systematic experimental research has been carried out. The results show that the axial impact force can suppress the stick-slip vibration by reducing the amplitude of weight on bit and torque fluctuations and by increasing the main frequency of torque. The amplitude of impact force affects the choice of the optimal back-rake angle. The impact frequency is negatively correlated with the fluctuation amplitude of the rotary speed. When the impact frequency is greater than 100 Hz, the fluctuation amplitude of the rotary speed will not decrease.

Research and Field Application of the Axial-Torsional Coupled Percussion Drilling Technology

2019 ◽  
Vol 142 (3) ◽  
Author(s):  
Zongjie Mu ◽  
Gensheng Li ◽  
Zhongwei Huang ◽  
Jingbin Li ◽  
Hengyu Song
Keyword(s):  
Impact Force ◽  
Field Application ◽  
Fluid Density ◽  
Direct Proportion ◽  
Impact Frequency ◽  
Axial Impact ◽  
Pump Rate ◽  
Drilling Technology ◽  
The Impact ◽  
Percussion Drilling

Abstract Enhancing the rate of penetration (ROP) is one of the goals pursued by the oil and gas drilling industry. It has been proved that percussion drilling is a feasible method to increase drilling efficiency. However, single percussion drilling technology (axial percussion or torsional percussion) cannot cater to the current needs. This paper proposed a new technology/tool called the axial-torsional coupled percussion drilling, which can use the advantages of the percussion drilling in a better way. Mechanical structure and working principle of this tool were first introduced in detail and the theoretical analysis of the impact force and the impact frequency were then conducted. It was found that both the axial impact force and the torsional impact force are in direct proportion to the fluid density and are in direct proportion to the square of the pump rate. Both the axial impact frequency and the torsional impact frequency are in direct proportion to the pump rate and are in direct proportion to the square root of the fluid density. Subsequently, a laboratory experiment was conducted to verify the above theoretical results. The tools were applied to the oil field in Xin Jiang province, China. Field application results indicate that the penetration rate of the test well is averagely 1.6–3.3 times as fast as that of the adjacent well.

scholarly journals Design of a New Type of Torsional Impactor and Analysis of Its Impact Performance

2021 ◽  
Vol 11 (22) ◽  
pp. 11037
Author(s):  
Xianfeng Tan ◽  
Zongtao Chen ◽  
Songcheng Tan ◽  
Longchen Duan ◽  
Chao Xu ◽  
...  
Keyword(s):  
Rotation Speed ◽  
Impact Force ◽  
Structural Characteristics ◽  
Structural Parameters ◽  
Impact Angle ◽  
Impact Frequency ◽  
Stick Slip ◽  
Transmission Shaft ◽  
New Type ◽  
The Impact

In view of the stick-slip phenomenon in deep and hard rock drilling, a new type of torsional impactor that can provide torsional impact vibration was designed. According to the working principle and structural characteristics of the designed torsional impactor, this paper theoretically analyzes the influences of different structural parameters and motion parameters on the impact frequency, impact force, and impact torque of the torsional impactor. The results show that the impact frequency f is directly proportional to the rotational speed VZ of the transmission shaft and the installed number n of torsional impact generating devices. Additionally, the impact force F is directly proportional to sine value of the impact angle α (i.e., sinα), impact hammer mass m, impact hammer rotation speed VZ (i.e., transmission shaft rotation speed), and impact hammer rotation radius r and is inversely proportional to action time Δt of the impact hammer and impact anvil. Furthermore, the impact torque M is directly proportional to the impact force F and rotary radius r of the impact hammer. This article lays a foundation for further theoretical and experimental research of torsional impactors and provides a reference for the design and testing of torsional impactors.

scholarly journals Axial Impact Load of a Concrete-Filled Steel Tubular Member with Axial Compression Considering the Creep Effect

Materials ◽  
2019 ◽  
Vol 12 (19) ◽  
pp. 3134 ◽  
Author(s):  
Tao Lan ◽  
Guangchong Qin ◽  
Jinzhao Zhuang ◽  
Youdi Wang ◽  
Qian Zheng ◽  
...  
Keyword(s):  
Impact Load ◽  
Slenderness Ratio ◽  
Concrete Strength ◽  
Pressure Ratio ◽  
Impact Resistance ◽  
Axial Pressure ◽  
Axial Impact ◽  
Creep Effect ◽  
The Impact ◽  
Peak Value

The dynamic loads acting on concrete-filled steel tubular members under axial impacts by rigid bodies were studied herein by FEM. The whole impact process was simulated and the time history of the impact load was obtained. The effects of eight factors on the axial impact load were studied; these factors were the impact speed, mass ratio, axial pressure ratio, steel ratio, slenderness ratio, concrete strength, impact position, and boundary conditions. Besides this, the effects of concrete creep on the impact load were also considered by changing the material parameters of the concrete. The results show that axial impact load changes with time as a triangle. The peak value of impact load increases and the impact resistance improves with the growth of the axial pressure ratio, steel ratio, slenderness ratio, and concrete strength after creep occurs. As the eccentricity of the axial impact acting on a concrete-filled steel tubular member increases, the peak value of the impact load decreases. The enhancement of constraints at both ends of the member can improve the impact resistance. The creep reduction coefficients for the peak axial impact load of a concrete-filled steel tubular member under axial compression and considering the creep effect over 6 months and 30 years are 0.60 and 0.55, respectively. A calculation formula for the peak value of impact load was suggested based on the existing formula, and its accuracy was proved by finite element calculation in this study.

Finite Element Analysis of a Single-Layer Reticulated Dome under Impact Loading

2010 ◽  
Vol 163-167 ◽  
pp. 327-331 ◽  
Author(s):  
Liang Zheng ◽  
Zhi Hua Chen
Keyword(s):  
Finite Element ◽  
Dynamic Response ◽  
Impact Force ◽  
Impact Load ◽  
Residual Deformation ◽  
Time History ◽  
Single Layer ◽  
Element Analysis ◽  
Deformation Stage ◽  
The Impact

Finite element model of both the single-layer Schwedler reticulated dome with the span of 50m and a Cuboid impactor were developed, incorporating ANSYS/LS-DYNA. PLASTIC_KINEMATIC (MAT_003) material model which takes stain rate into account was used to simulate steel under impact load. The automatic point to surface contact (NODES TO SURFACE) was applied between the dome and impact block. Three stages of time history curve of the impact force on the apex of the single-layer Scheduler reticulated dome including the impact stage, stable stalemate stage, the decaying stage were generalized according to its dynamic response. It must be pointed out that the peak of the impact force of the single-layer reticulated dome increase with the increase of the weight and the velocity of the impact block, but the change of the velocity of the impact block is more sensitive than the change of weight of the impact block for the effect of the peak of the impact force, and a platform value of the impact force of the single-layer reticulated dome change near a certain value, and the duration time of the impact gradually increase. Then four stages of time history curve of the impact displacement were proposed according to the dynamic response of impact on the apex of the single-layer reticulated dome based on numerical analysis. Four stages include in elastic deformation stage, plastic deformation stage, elastic rebound stage, free vibration stage in the position of the residual deformation.

Fabrication of Hydraulic Bumper for Anti-Collision in a Vehicle

2015 ◽  
Vol 766-767 ◽  
pp. 499-504 ◽  
Author(s):  
M. Anish ◽  
R. Thamaraikannan ◽  
B. Kanimozhi ◽  
Ham G. Varghese ◽  
Shem G. Varghese
Keyword(s):  
System Design ◽  
Automotive Industry ◽  
Production Cost ◽  
Impact Force ◽  
Impact Load ◽  
Suitable Material ◽  
Fiber Plastic ◽  
The Cost ◽  
The Impact ◽  
Bumper System

Improvement of bumper system is crucial in the automotive industry. The main objectives are to increase the performance of the bumper and also to find a solution to reduce the cost of the bumper thereby facilitating the reduction of production cost. The cost of bumper is high owing to the amount of material used and various processes involved .The new design considers on reducing the amount of material use and adding improved hydraulics instead of normal bumper to give cushioning effect and also assures safety in low speed collision. The new design also improves the ability to absorb more impact load and increase the protection of the front car component. The methodology employed was the study of the front bumper system, design and fabrication. The suitable material that can be used as the bumper in terms of economical but still maintaining the toughness is Plastic-Polycarbonate (Molded) which is not expensive compared to the best material from the analysis of E-Glass Fiber, Plastic-Nylon Type 6/6 and Plastic ABS (Molded). The suitable material to be used for making beam is AISI E52100 Steel. Rearrangement of the mounting positions gives a different effect on the ability to withstand the impact force.

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.

Analysis of Dynamic Response of Mine Rescue Chamber under Axial Impact Load

2011 ◽  
Vol 211-212 ◽  
pp. 576-580 ◽  
Author(s):  
Ming Song ◽  
Shi Rong Ge ◽  
Hai Feng Fang
Keyword(s):  
Dynamic Response ◽  
Impact Load ◽  
Element Model ◽  
Deformation Energy ◽  
Spherical Shells ◽  
Tunnel Wall ◽  
Axial Impact ◽  
Plate And Shell ◽  
The Impact ◽  
Mine Rescue

In order to research the problem of rescue chamber colliding with the tunnel wall. The theoretical model of rescue chamber has been formed, based on the principle of energy conservation, by using theories of plates and shells, large deformed plate and shell, and by analysis of dynamic response of mine rescue chamber under axial impact load. This model includes initial velocity, contact force deformation energy and shell deformation. Dytran software was applied to build the finite element model of the rescue chamber contacting the rigid plate. Through comparison emulation result and theoretical analysis result, this model is proved to be highly reliable. The theoretical calculation and the simulation indicated that there were obvious relationships among the ability of the mine rescue chamber under axial impact load with the thickness, depth of flat spherical shells. If the thickness or depth increases, then the chamber could stand more. It is also confirmed that increasing the depth of flat spherical shells can minish the impact force for making impact process abate, which provides a basis for the research of rescue chamber.

Mathematical modeling of viscoelastic material under impact load

2019 ◽  
Vol 54 (2) ◽  
pp. 130-138
Author(s):  
Md Fazlay Rabbi ◽  
Vijaya B Chalivendra
Keyword(s):  
Storage Modulus ◽  
Viscoelastic Material ◽  
Impact Force ◽  
Impact Load ◽  
Viscoelastic Behavior ◽  
Maximum Displacement ◽  
Drop Weight ◽  
Tan Δ ◽  
The One ◽  
The Impact

A linear physics-based model is developed to investigate the one-dimensional impact on a viscoelastic material. A generalized model with three Maxwell elements is considered to describe the viscoelastic behavior. An analytical method based on Laplace transformation is used to solve the impact problem. To have a comprehensive understanding of viscoelastic material response, drop-weight impact is also considered in this study. For both linear impact and drop-weight cases, a maximum reduction of 15% of the impact force as well as 32% higher energy absorption can be achieved with the increase in tan δ from 0.01 to 0.8 of viscoelastic material. In addition, for linear impact, impact force decreases by 20% when tan δ = 1. With the increase in tan δ, storage modulus decreases by around 57% for maintaining a predetermined deformation. Moreover, for almost constant maximum displacement, materials with a higher storage modulus absorb more impact energy and experience higher impact force as compared to materials with a lower storage modulus.

scholarly journals Retrofitting Options for Un-Reinforced Brick Wall Subjected to Impact Load

2012 ◽  
Vol 602-604 ◽  
pp. 1574-1578
Author(s):  
Norazman Mohamad Nor ◽  
Mohd Azizul Mohd Noor ◽  
Mohammed Alias Yusof ◽  
Ahmad Mujahid Ahmad Zaidi ◽  
Shohaimi Abdullah
Keyword(s):  
Impact Test ◽  
Impact Force ◽  
Impact Load ◽  
Brick Wall ◽  
Failure Patterns ◽  
The Third ◽  
Blast Energy ◽  
Flexural Testing ◽  
New Construction ◽  
The Impact

In this research we investigate the possibility of enhancing the way brick walls can be retrofitted in an economical manner and become more resistant to blast impact. Retrofitting a method usually done on constructed walls; however, the same strengthening procedures can also be applied to a new construction project. In this research we investigate three methods of reinforcing brick walls against blast impact. First, reinforcing the brick layer using carbon fiber strips only without epoxy, with the fiber being placed on the bare bricks before it is plastered with mortar finishing, second, reinforcing the brick wall by placing CFRP onto the bare bricks and fixing with epoxy prior to finishing or being plastered over with mortar, and third, retrofitting the outer surface of a finished, or plastered, brick wall with CFRP and fixed with epoxy as is commonly done. The impact test was conducted using a drop weight released at a fixed height to simulate blast energy of an explosion. The effects of the test on all the samples were observed to identify failure patterns. Flexural testing was also conducted to observe how the samples perform under normal flexural loading. It was discovered that the second option, i.e. placing the CFRP on the bare bricks and fixing with epoxy before it is finished or plastered over with mortar, performs the best. This is due to the CFRP being firmly fixed before mortar finishing, causing the CFRP to be held steadily in place during the impact, thus, helping the wall to resist the impact load. With the third option, the CFRP was able to resist the impact but, as has been observed in other studies, the CFRP delaminates from the wall. The first option does not work very well since the mortar is unable to perform as well as the epoxy in holding the fiber to the wall to resist the impact force. Thus, for plastered brick walls, it is better suited for it to be reinforced by FRP under the finished mortar rather than on it, thus reducing the problem of delaminated FRP from the wall surface.

Development of a high-frequency torsional impact generator for improving drilling efficiency

2013 ◽  
Vol 228 (11) ◽  
pp. 1968-1977 ◽  
Author(s):  
Xiaohua Zhu ◽  
Liping Tang
Keyword(s):  
High Frequency ◽  
Oil And Gas ◽  
Impact Frequency ◽  
Element Analysis ◽  
Stick Slip ◽  
Deep Wells ◽  
Experimental Apparatus ◽  
The Finite Element Analysis ◽  
Drilling Technology ◽  
The Impact

The drilling of deep wells has to face problems to suppress stick-slip vibrations, especially for tough formations. Such problems induce frequent tool failures and poor well quality. Torsional impact drilling is an emerging drilling technology for improving the productivity of oil and gas by mitigating the stick-slip vibration. In this paper, a high-frequency torsional impact generator has been developed in order to investigate this drilling technology. Mechanism of torsional impact as a means of stick-slip mitigation is studied. Structure and operating principle of the tool have been presented. The finite element analysis approach is utilized in the analysis of applicability of the impact unit which is most significant for the tool. The analysis indicates that the impact unit operates successfully. An experimental apparatus is developed to examine the applicability of the proposed numerical method to the analysis of the impact unit. Laboratory tests with different impact frequency are conducted with the apparatus. It is verified that the impact system operates regularly, and high-frequency torsional impacts are generated. In addition, impact parameters of the apparatus which will be helpful to the study of the high-frequency torsional impact drilling are obtained.

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