Study on Composite Design Suitable for High Hardness and Strong Abrasive Formation

PDC (Polycrystalline Diamond Compact bit) composite is the most important cutting element of petroleum bit, which performance directly affects the service effect and service life of the bit. During the drilling process, the cutter will produce a large amount of friction heat when cutting the rock, resulting in a sharp increase in the internal temperature of the cutter. When the temperature reaches a certain value, thermal wear and tear are very easy to occur, which will not only cause diamond delamination but also reduce the wear resistance of the cutter. Under the action of impact load, impact failure is more likely to occur, which greatly reduces the service life of the cutter and the rock-breaking efficiency of the drill bit. Therefore, this paper studies the composite interface suitable for high-temperature drilling through the changes of cutting tooth temperature field and stress field with different interface shapes, which shows that the non-planar interface is more suitable for improving the cutting tooth life of composite under the action of comprehensive stress field.

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Application of an innovative ridge-ladder-shaped polycrystalline diamond compact cutter to reduce vibration and improve drilling speed

Science Progress ◽

10.1177/0036850420930971 ◽

2020 ◽

Vol 103 (3) ◽

pp. 003685042093097

Author(s):

Dou Xie ◽

Zhiqiang Huang ◽

Yuqi Yan ◽

Yachao Ma ◽

Yuan Yuan

Keyword(s):

Oil And Gas ◽

Polycrystalline Diamond ◽

Rock Breaking ◽

Drilling Process ◽

Drilling Speed ◽

Stick Slip ◽

Gas Drilling ◽

Drill Bits ◽

Element Simulation ◽

Polycrystalline Diamond Compact

Polycrystalline diamond compact bits have been widely used in the Oil and Gas drilling industry, despite the fact that they may introduce undesired vibration into the drilling process, for example, stick-slip and bit bounce, which accelerate the failure rate and lead to higher drilling costs. First, we develop an innovative ridge-ladder-shaped polycrystalline diamond compact cutter, which has ridge-shaped cutting faces and multiple cutting edges with stepped distribution, in the hope of reducing vibration and improving drilling speed. Then, the scrape tests of ridge-ladder-shaped and general polycrystalline diamond compact cutters are carried out in a laboratory, indicating that the cutting, lateral, and longitudinal forces on ridge-ladder-shaped polycrystalline diamond compact cutters are smaller and with minor fluctuations. Due to different rock-breaking mechanisms, ridge-ladder-shaped polycrystalline diamond compact cutters have higher cutting efficiency compared to general polycrystalline diamond compact cutters, which is also verified experimentally. Finally, the drilling characteristics of a new polycrystalline diamond compact bit fitted with some ridge-ladder-shaped polycrystalline diamond compact cutters are compared to those of a general polycrystalline diamond compact bit by means of finite element simulation. The results show that introducing ridge-ladder-shaped polycrystalline diamond compact cutters can not only reduce the stick-slip vibration, bit bounce, and backward rotation of drill bits effectively, but also improve their rate of penetration.

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Kinematic and bottom-hole pattern analysis of a composite drill bit of cross-scraping

Proceedings of the Institution of Mechanical Engineers Part C Journal of Mechanical Engineering Science ◽

10.1177/0954406216642797 ◽

2016 ◽

Vol 231 (17) ◽

pp. 3104-3117 ◽

Cited By ~ 3

Author(s):

Yingxin Yang ◽

Chunliang Zhang ◽

Lian Chen ◽

Yong Liu

Keyword(s):

Polycrystalline Diamond ◽

Rock Breaking ◽

Speed Ratio ◽

Drill Bit ◽

The Novel ◽

Analysis Model ◽

Fracture Failure ◽

Bottom Hole ◽

Geometric Relationship ◽

Polycrystalline Diamond Compact

For improving the drilling efficiency of polycrystalline diamond compact drill bit, a novel polycrystalline diamond compact drill bit is presented with a new rock-breaking method named as cross-scraping. In the novel polycrystalline diamond compact drill bit which is referred to as a composite drill bit, polycrystalline diamond compact cutters are mounted on rotary wheels as major cutting elements, and as a result, mesh-like scraping tracks are formed in the outer radial area of the bottom-hole. Rock-breaking method of the composite drill bit causes both shearing and fracture failure of the bottom-hole rock, which will greatly increase the rock-breaking efficiency and will prolong the bit service life. By analyzing the complex motion of cutters on the composite drill bit, velocity and acceleration models of the cutters, as well as wheel/bit speed ratio model of the bit are established in accordance with the geometric relationship between cutters and bit body in a compound coordinate system. In simulation examples, motion tracks, velocity and acceleration features of the cutter and especially the bottom-hole pattern are analyzed. Further, indoor experiments are conducted to test the mesh-like bottom-hole pattern and rock-breaking features, which have proved the accuracy of the analysis model of the composite drill bit.

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Mathematical Modeling of PDC Bit Drilling Process Based on a Single-Cutter Mechanics

Journal of Energy Resources Technology ◽

10.1115/1.2906429 ◽

1993 ◽

Vol 115 (4) ◽

pp. 247-256 ◽

Cited By ~ 18

Author(s):

A. K. Wojtanowicz ◽

E. Kuru

Keyword(s):

Polycrystalline Diamond ◽

Rock Properties ◽

Drilling Process ◽

Drilling Parameters ◽

Pdc Bit ◽

Analytical Development ◽

Assumed Similarity ◽

Balance Of Forces ◽

Bit Life ◽

Polycrystalline Diamond Compact

An analytical development of a new mechanistic drilling model for polycrystalline diamond compact (PDC) bits is presented. The derivation accounts for static balance of forces acting on a single PDC cutter and is based on assumed similarity between bit and cutter. The model is fully explicit with physical meanings given to all constants and functions. Three equations constitute the mathematical model: torque, drilling rate, and bit life. The equations comprise cutter’s geometry, rock properties drilling parameters, and four empirical constants. The constants are used to match the model to a PDC drilling process. Also presented are qualitative and predictive verifications of the model. Qualitative verification shows that the model’s response to drilling process variables is similar to the behavior of full-size PDC bits. However, accuracy of the model’s predictions of PDC bit performance is limited primarily by imprecision of bit-dull evaluation. The verification study is based upon the reported laboratory drilling and field drilling tests as well as field data collected by the authors.

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Simulation and Experimental Study of the Rock Breaking Mechanism of Personalized Polycrystalline Diamond Compact Bits

Journal of Engineering Science and Technology Review ◽

10.25103/jestr.135.16 ◽

2020 ◽

Vol 13 (5) ◽

pp. 122-131

Author(s):

Yu Jinping ◽

◽

Zou Deyong ◽

Sun Yuanxiu ◽

Zhang Yin

Keyword(s):

Experimental Study ◽

Finite Element ◽

Tensile Stress ◽

Crack Propagation ◽

Tangential Force ◽

Polycrystalline Diamond ◽

Rock Breaking ◽

Pdc Bit ◽

Breaking Mechanism ◽

Polycrystalline Diamond Compact

Rock breaking is a complex physical process that can be influenced by various factors, such as geometrical shape and cutting angle of rock breaking tools. Experimental study of the rock breaking mechanism of personalized bits is restricted due to long cycle and high cost. This study simulated the rock breaking mechanism of polycrystalline diamond compact (PDC) bit by combining finite element method and experiment. The simulation was performed to shorten the period and reduce the cost of studying the rock breaking mechanism of PDC bits. A rock breaking finite element model for sting cutters of personalized PDC bit was established to simulate the rock breaking process. The crack propagation pattern, dynamic stress of rock breaking, and rock breaking mechanism of sting cutters of personalized PDC bit were analyzed. The correctness of the simulation results was verified through experiments. Results demonstrate that the rock breaking load increases with the crack propagation in the fracture initiation and propagation stages, with the maximum tangential force of 1062.5 N and maximum axial force of 1850.0 N. The load changes in a small range when the crack penetrates the rock, with the tangential force of 125.0–500.0 N and axial force of 375.0–875.0 N. The rock breaking mechanism of the sting cutters of bit is consistent with maximum tensile stress theory. The rock begins to break when the tensile stress of rock is 36.9 MPa. The sting cutters of personalized PDC bit have better wear resistance than the sting cutters of conventional bit. The average wear rates of personalized PDC and conventional bits are 1.74E-4 and 2.1E-4 mm/m, respectively. This study serves as reference for shortening the study period of rock breaking mechanism, efficiently designing personalized PDC bit structure, reducing bit wear, and enhancing rock breaking efficiency.

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The wear analysis model and rock-breaking mechanism of a new embedded polycrystalline diamond compact

Proceedings of the Institution of Mechanical Engineers Part C Journal of Mechanical Engineering Science ◽

10.1177/0954406216664755 ◽

2016 ◽

Vol 231 (22) ◽

pp. 4241-4249 ◽

Cited By ~ 5

Author(s):

Jialin Tian ◽

Gang Liu ◽

Lin Yang ◽

Chunming Wu ◽

Zhi Yang ◽

...

Keyword(s):

Wear Mechanism ◽

Polycrystalline Diamond ◽

Rock Breaking ◽

Rapid Decline ◽

Analysis Model ◽

Diamond Layer ◽

Gas Drilling ◽

Wear Analysis ◽

Carbide Matrix ◽

Polycrystalline Diamond Compact

Polycrystalline diamond layer peel-off is a hot topic in oil and gas drilling engineering. When an integrated polycrystalline diamond compact cutter suffers overload, there is a rapid decline in its rock-breaking performance and drilling rate of penetration. To modify the comprehensive performance of polycrystalline diamond compact, we innovatively propose a new embedded polycrystalline diamond compact. According to geometric analysis theory combined with the linear combination rule, the three typical embedded design schemes – the imitation palm-shaped, imitation Z-shaped and ring-embedded designs – are discussed. The influences of the number, size, location and combination of the embedded polycrystalline diamond layer on the polycrystalline diamond compact wear mechanism and rock-breaking performance are analysed. The results show that the embedded element and carbide matrix are combined by brazing welding, which not only exerts high abrasion resistance on the polycrystalline diamond layer but also combines with the good impact performance of carbide matrix. Compared with ordinary polycrystalline diamond compact, the intake amount of a single-embedded polycrystalline diamond compact is smaller, and it wears more evenly during the rock-breaking process. Comparing the results from before and after drilling, it effectively prevents the ordinary polycrystalline diamond compact from easily peeling off when suffering overload. The unique wear analysis model can be applied to other types of polycrystalline diamond compact by adjusting the embedding method. The research conclusions provide useful insights into the study of the polycrystalline diamond compact wear mechanism and rock-breaking performance.

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Analysis of Rock Dynamic Stresses During the Drilling by Polycrystalline Diamond Compact Bits

International Journal of Simulation Modelling ◽

10.2507/ijsimm19-4-532 ◽

2020 ◽

Vol 19 (4) ◽

pp. 607-618

Author(s):

J. P. Yu ◽

D. Y. Zou ◽

Y. Zhang

Keyword(s):

Axial Force ◽

Dynamic Stress ◽

Tangential Force ◽

Polycrystalline Diamond ◽

Rock Breaking ◽

The Finite Element Method ◽

Principal Stresses ◽

Dynamic Stresses ◽

Polycrystalline Diamond Compact ◽

Initial Rock

In view of shortening the development period of polycrystalline diamond compact (PDC) bits, the finite element method was adopted to simulate the dynamic stress of rocks. By employing drilling related theories, the three dynamic principal stresses of rock were analysed and the dynamic rock-breaking criterion was established. Second, the drilling model of PDC core bit was constructed, and the stress was simulated and calculated. Finally, laboratory tests were carried out to verify the simulation results. The analytical results demonstrate that the two obvious stages in the rock-breaking process are the initial rock-breaking stage and the normal one. The dynamic rock-breaking stress in the normal drilling stage varies from 66.3 to 99.6 MPa, which is lower than 278.4 MPa in the initial rock-breaking stage. During spud drilling, the axial force and the tangential force are 1.85 and 1.60 kN, respectively. During normal drilling, the axial force ranges from 0.2 to 0.9 kN, and the tangential force from 0.15 to 0.6 kN. The load of normal drilling is lower than the spudding load, and the bit is more likely to be damaged during spudding. The bit is normally worn during normal drilling.

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Investigation of the Cross-Cutting Polycrystalline Diamond Compact Bit Drilling Efficiency

Shock and Vibration ◽

10.1155/2021/8841255 ◽

2021 ◽

Vol 2021 ◽

pp. 1-15

Author(s):

Chun-Liang Zhang ◽

Ying-Xin Yang ◽

Hai-Tao Ren ◽

Can Cai ◽

Yong Liu ◽

...

Keyword(s):

Cutting Force ◽

Polycrystalline Diamond ◽

Rock Breaking ◽

The Novel ◽

Cutting Efficiency ◽

Bottom Hole ◽

Pdc Bit ◽

The Cross ◽

Polycrystalline Diamond Compact ◽

Cutting Modes

The parallel track scraping principle of conventional PDC bits largely limits the cutting efficiency and working life in deep formations. Cross-cutting polycrystalline diamond compact (PDC) bit may be an efficient drilling tool that increases the rock-breaking efficiency through both cross-cutting and alternate-cutting modes of the PDC cutter. The motion track equation of the cross-cutting PDC bit was derived by using the compound coordinate system, and the motion track was analyzed. Meanwhile, through the unit experiment and discrete element simulation, the cutting force, volume-specific load, and crack propagation were analyzed under different cutting modes. Through establishing a nonlinear dynamic model of the bit-rock system, the speed-up mechanism of the novel bit was analyzed based on rock damage, rock stress state, and motion characteristic of the bit during the rock-breaking process. Compared with unidirectional cutting, cross-cutting produces less cutting force, more brittle fracture, and a greater decrease of formation strength. The novel PDC bit can put more rock elements into a tensile stress condition than a conventional PDC bit, and the plastic energy dissipation ratio of the cross-cutting PDC bit is lower while the damage energy consumption ratio is higher than they are for conventional bits, which is beneficial to increasing the ratio of fracture failure and improving rock-breaking efficiency. Laboratory drilling tests show that the cross-cutting PDC bit can create mesh-like bottom-hole features. Drilling contrast experiments show that a mesh-like bottom-hole pattern can be obtained by using the cross-cutting PDC bit, of which the ROP is obviously higher than that of the conventional bit when drilling in sandstone or limestone formation. Meanwhile, the influence of deviation angle, weight on bit, and rock properties on cutting efficiency of the cross-cutting PDC bit are studied.

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The Development of the Microwave Assisted Rock Breaking Device

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.900.627 ◽

2014 ◽

Vol 900 ◽

pp. 627-630 ◽

Cited By ~ 2

Author(s):

Guang Tong Feng ◽

Zong Gang Wang ◽

Zhen Wei

Keyword(s):

Service Life ◽

Hot Spot ◽

Near Field ◽

Rock Breaking ◽

Field Energy ◽

Drill Bit ◽

Microwave Generator ◽

Impact Wear ◽

Microwave Assisted ◽

Wear And Tear

Microwave crag broken is a thermal assisted rock breaking method which could melt rocks. Microwave assisted rock breaking method will not bring new impact, wear and tear, instead, the microwave pretreatment on the rock reduces the difficulty of breaking rock and prolongs the service life of the drill bit. This microwave generator accumulates the microwave near the hot spot to soften and melt the rock through generating and transmitting the microwave. And we had experimented with the microwave generator to penetrate the wood, and weaken the strength of the rock. And the experiment proved the scheme of the microwave assisted rock breaking through microwave near field energy and the thermal runaway effect is feasible.

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Design and test of a self-adaptive bionic polycrystalline diamond compact bit inspired by cat claw

Advances in Mechanical Engineering ◽

10.1177/1687814018810249 ◽

2018 ◽

Vol 10 (11) ◽

pp. 168781401881024

Author(s):

Qiongqiong Tang ◽

Wei Guo ◽

Ke Gao ◽

Rongfeng Gao ◽

Yan Zhao ◽

...

Keyword(s):

Service Life ◽

Soft Rock ◽

Polycrystalline Diamond ◽

Rake Angle ◽

The Self ◽

Test Results ◽

Short Service Life ◽

Polycrystalline Diamond Compact ◽

Rock Strata ◽

Self Adaptive

Cats protract claws while hunting or pawing on the ground and retract to muscles when relaxing. Inspired by this behavior, and in order to solve the problem of short service life and low comprehensive drilling efficiency of polycrystalline diamond compact bits which results from its poor adaptability to soft-hard interbedded strata, a self-adaptive bionic polycrystalline diamond compact bit was designed, which can use the elastic element to adjust its back-rake angle according to the formation hardness to improve the adaptability of polycrystalline diamond compact bits. Theoretical analysis and drilling test results show that the self-adaptive bionic polycrystalline diamond compact bit has a strong adaptability to soft-hard interbedded rock strata. When drilling in soft rock, the back-rake angle is small and the rate of penetration is high; when drilling in hard rock, the angle becomes larger to reduce the abnormal damage of cutters. Thus, it can improve the integrated drilling efficiency and service life of polycrystalline diamond compact bits. In the whole drilling test, the average penetration rate of the self-adaptive bionic polycrystalline diamond compact bit increases by 10%–13% over conventional polycrystalline diamond compact bits with the same dimension and material.

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