scholarly journals RESEARCH OF A LATERAL REAMER BIT FOR DIGGING PLANTING HOLE IN ROCKY ABANDONED MINE AREA

2021 ◽  
pp. 119-128
Author(s):  
Haifeng Luo ◽  
Chaoyu Chen
Keyword(s):  
Polycrystalline Diamond ◽  
Abandoned Mine ◽  
Mine Area ◽  
Time Length ◽  
Metamorphic Mechanism ◽  
Pdc Bit ◽  
Karst Landform ◽  
Screw Mechanism ◽  
Polycrystalline Diamond Compact ◽  
Mapping Models

In the abandoned mine area with Karst landform in China, soils are few and thin but rocks are common, traditional planting hole diggers are unequal to work in rocks for vegetation restoration. A reamer bit with variable lateral drilling radius was designed based on the PDC (polycrystalline diamond compact) bit technology and metamorphic mechanism. Two lateral camber blades with PDC teeth were installed inside the bit body, a screw mechanism was employed as the actuation and a spatial double triangle mechanism was taken for the transmission. The curve of the camber blade was specially defined thus the reaming load was decentralized to 85.7% teeth on the blade. The kinematics of the lateral reamer bit was analysed, the mapping models from the actuation to the reaming radius and speed were established. Concrete samples were reamed indoors from 240mm to 407mm in diameter, the reaming cutting load and time length were measured and analysed. The lateral reamer bit was approved with the experiment results, this study provided equipment support for digging the planting hole in rocky abandoned mine areas and also expanded the PDC bit application.

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

1993 ◽  
Vol 115 (4) ◽  
pp. 247-256 ◽  
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.

Issues in Polycrystalline Diamond Compact Cutter–Rock Interaction From a Metal Machining Point of View—Part II: Bit Performance and Rock Cutting Mechanics

2012 ◽  
Vol 134 (6) ◽  
Author(s):  
Demeng Che ◽  
Peidong Han ◽  
Ping Guo ◽  
Kornel Ehmann
Keyword(s):  
Metal Cutting ◽  
Polycrystalline Diamond ◽  
Rock Cutting ◽  
Point Of View ◽  
Rock Interaction ◽  
Metal Machining ◽  
Pdc Bit ◽  
Rock Cutting Mechanics ◽  
Cutting Processes ◽  
Polycrystalline Diamond Compact

In Part I of this paper, the issues related to temperature, stress and force were reviewed and parallels were drawn between both metal machining and rock cutting. Part II discusses the issues more directly related to polycrystalline diamond compact (PDC) bit performance and rock mechanics. However, relevant issues in various metal cutting processes will continue to be presented to clarify the gaps and similarities between these two classes of processes.

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

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.

First Application of Hybrid Bit Technology to Optimize Drilling Through S Shape Directional Section with High Chert Content in UAE Land Operations

2021 ◽  
Author(s):  
Ygnacio Jesus Nunez ◽  
Munir Bashir ◽  
Fernando Ruiz ◽  
Rakesh Kumar ◽  
Mohamed Sameer ◽  
...  
Keyword(s):  
Good Condition ◽  
Polycrystalline Diamond ◽  
Steering System ◽  
Directional Drilling ◽  
Main Challenge ◽  
Drilling Parameters ◽  
Pdc Bit ◽  
Heterogeneous Formation ◽  
Polycrystalline Diamond Compact ◽  
Cutting Mechanisms

Abstract This paper highlights the solution, execution, and evaluation of the first 12.25″ application of hybrid bit on rotary steerable system in S-Shape directional application to drill interbedded formations with up to 25 % chert content in UAE land operations. The main challenge that the solution overcame is to drill through the hard chert layers while avoiding trips due to PDC bit damage nor drilling hour's limitation of TCI bit while improving the overall ROP and achieving the directional requirement. The solution package has demonstrated a superior ROP over rollercone bits, as well as improved PDC cutter durability and lower reactive torque leading to better steerability and stability which will be detailed in this paper. A significant contributor to such success was utilizing a new hybrid bit technology which incorporates the dual cutting mechanisms of both polycrystalline Diamond Compact (PDC) and rollercone bits. This allows a more efficient drilling by bringing the durability of the crushing action of rollercone to drill through hard interbedded lithology and the effectiveness of the shearing action of PDC cutters to improve ROP without sacrificing the toughness of the cutting structure edge. The proposed solution in combined with continues proportional rotary steering system managed to drill 4,670 ft through heterogeneous formation with chert nodules, with an average ROP of 38.29 ft\hr improving ROP by 15% and eliminating extra trips of utilizing roller cone bits to be able to drill though the chert nodules and avoid the PDC bit damage. Leading reduction in cost per foot by 35 %. Additionally, the hybrid bit exceed the expectation achieving 878 thousand of revolutions, with effective bearing and with the drilling cutting structure in a very good condition. Furthermore, the directional objectives were met with high quality directional drilling avoiding wellbore tortuosity. Such success was established through application analysis, specific formations drilling roadmaps and optimized drilling parameters in order to improve the overall run efficiency. The combination of roller cone and PDC elements in a hybrid bit designed to deliver better efficiency and torque stability significantly increased performance drilling the section in one single run, proven that heterogeneous formations can be drill.

Hybrid Physics-Field Data Approach Improves Prediction of ROP / Drilling Performance of Sharp and Worn PDC Bits

2021 ◽  
Author(s):  
Guodong David Zhan ◽  
Arturo Magana-Mora ◽  
Eric Moellendick ◽  
John Bomidi ◽  
Xu Huang ◽  
...  
Keyword(s):  
Prediction Models ◽  
Collaborative Study ◽  
Hybrid Approach ◽  
Polycrystalline Diamond ◽  
Rock Properties ◽  
Quantitative Prediction ◽  
Model Learning ◽  
Drilling Performance ◽  
Pdc Bit ◽  
Polycrystalline Diamond Compact

Abstract This study presents a hybrid approach that combines data-driven and physics models for worn and sharp drilling simulation of polycrystalline diamond compact (PDC) bit designs and field learning from limited downhole drilling data, worn state measurements, formation properties, and operating environment. The physics models include a drilling response model for cutting forces, worn or rubbing elements in the bit design. Decades of pressurized drilling and cutting experiments validated these models and constrained the physical behaviour while some coefficients are open for field model learning. This hybrid approach of drilling physics with data learning extends the laboratory results to application in the field. The field learning process included selecting runs in a well for which rock properties model was built. Downhole drilling measurements, known sharp bit design, and measured wear geometry were used for verification. The models derived from this collaborative study resulted in improved worn bit drilling response understanding, and quantitative prediction models, which are foundational frameworks for drilling and economics optimization.

Fragmentation Characteristics of Rocks Under Indentation by a Single Polycrystalline Diamond Compact Cutter

2021 ◽  
Vol 143 (10) ◽  
Author(s):  
Zhaosheng Ji ◽  
Huaizhong Shi ◽  
Xianwei Dai ◽  
Hengyu Song ◽  
Gensheng Li ◽  
...  
Keyword(s):  
Contact Force ◽  
Brittle Failure ◽  
Failure Modes ◽  
Polycrystalline Diamond ◽  
Rake Angle ◽  
Von Mises Stress ◽  
Rock Interaction ◽  
Initiation Point ◽  
Pdc Bit ◽  
Polycrystalline Diamond Compact

Abstract Polycrystalline diamond compact (PDC) bit accounts for the most drilling footage in the development of deep and geothermal resources. The goal of this paper is to investigate the PDC cutter-rock interaction and reveal the rock fragmentation mechanism. A series of loading and unloading tests are conducted to obtain the curves of contact force versus penetration displacement. A single practical PDC cutter is fixed on the designed clamping devices that are mounted on the servo experiment system TAW-1000 in the tests. The craters morphology and quantified data were obtained by scanning the fragmented rock specimen using a three-dimensional morphology scanner. Finally, a numerical model is established to get the stress and deformation fields of the rock under a single PDC cutter. The results show that there are two kinds of failure modes, i.e., brittle failure and plastic failure, in the loading process. Marble is more prone to brittle fracture and has the lowest specific energy, followed by shale and granite. The brittle failure in marble mainly occurs behind the cutter while that happens ahead of the cutter for shale. Curves of contact force versus penetration displacement illustrate that a cutter with a back rake angle of 40 deg has a better penetration result than that with a back rake angle of 30 deg. Enhancing loading speed has a positive effect on brittle fragmentation. The distribution of von Mises stress indicates the initiation point and direction, which has a good agreement with the experiment. The research is of great significance for optimizing the PDC bit design and increasing the rate of penetration.

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

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.

Study of the Influence of Controlled Axial Oscillations of pVARD on Generating Downhole Dynamic WOB and Improving Coring and Drilling Performance in Shale

2019 ◽  
Author(s):  
Abdelsalam N. Abugharara ◽  
John Molgaard ◽  
Charles A. Hurich ◽  
Stephen D. Butt
Keyword(s):  
Sampling Rate ◽  
Polycrystalline Diamond ◽  
Rotary Drilling ◽  
Labview Software ◽  
Drilling Performance ◽  
Drilling Parameters ◽  
Wide Range ◽  
Pdc Bit ◽  
Weight On Bit ◽  
Polycrystalline Diamond Compact

Abstract This work concentrates on the investigation of enhancing drilling performance through increasing drilling rate of penetration (ROP) by using a passive vibration assisted rotary drilling (pVARD) tool. It also involves analysis of how ROP was significantly increased when drilling using pVARD compared to drilling using conventional system “rigid” using coring and drilling in shale rocks. The apparatus used was a fully instrument laboratory scale rig and the bits were dual-cutter polycrystalline diamond compact (PDC) bit for drilling and diamond impregnated coring bit for coring. The flow rate was constant of (7 litter / min) using clean water at atmospheric pressure. In addition, for accuracy data recording, a data acquisition system (DAQ-Sys) using a LabVIEW software was utilized to record data at 1000HZ sampling rate. The output drilling parameters involved in the analysis included operational rpm, torque (TRQ), and ROP. All the output-drilling parameters were analyzed with relation to downhole dynamic weight on bit (DDWOB). The result of this work explained how pVARD can increase the DDWOB and improve ROP. The result also demonstrated generating a balanced and concentric increase in DDWOB and minimizing the wide-range fluctuation of DDWOB generated in rigid drilling, particularly at high DDWOB.

Analysis of Coupling Between Axial and Torsional Vibration in a Compliant Model of a Drillstring Equipped With a PDC Bit

2002 ◽  
Author(s):  
M. A. Elsayed ◽  
David W. Raymond
Keyword(s):  
Hard Rock ◽  
Polycrystalline Diamond ◽  
Operating Conditions ◽  
Axial Vibration ◽  
Rock Drilling ◽  
Stick Slip ◽  
Vibration Data ◽  
Pdc Bit ◽  
Show Evidence ◽  
Polycrystalline Diamond Compact

In this paper, we discuss results of rock drilling tests at Sandia National Laboratories’ Hard Rock Drilling Facility (HRDF). The HRDF incorporates a drillstring with axial and torsional compliance and is equipped with a coring bit having PDC (Polycrystalline Diamond Compact) cutters. We measure and analyze chatter and show evidence of stick-slip as well as coupling between axial and torsional vibrations. We show the coupling signature in axial vibration data in the form of side bands indicating frequency modulation at the torsional natural frequency. The influence of operating conditions on the bit response is shown.

Development of New PDC Bits for Drilling of Geothermal Wells—Part 1: Laboratory Testing

1992 ◽  
Vol 114 (4) ◽  
pp. 323-331 ◽  
Author(s):  
H. Karasawa ◽  
S. Misawa
Keyword(s):  
Hard Rock ◽  
Rock Type ◽  
Penetration Rate ◽  
Polycrystalline Diamond ◽  
Rock Cutting ◽  
Rake Angle ◽  
Well Drilling ◽  
Pdc Bit ◽  
Geothermal Wells ◽  
Polycrystalline Diamond Compact

Rock cutting, drilling and durability tests were conducted in order to obtain data to design polycrystalline diamond compact (PDC) bits for geothermal well drilling. Both conventional and new PDC bits with different rake angles were tested. The rock cutting tests revealed that cutting forces were minimized at −10 deg rake angle independent of rock type. In drilling and durability tests, a bit with backrake and siderake angles of −10 or −15 deg showed better performance concerning the penetration rate and the cutter strength. The new PDC bit exhibited better performance as compared to the conventional one, especially in hard rock drilling. Furthermore, a new PDC core bit (98.4 mm o. d., 66 mm i. d.) with eight cutters could be successfully applied to granite drilling equally as well as a bit with twelve cutters.

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