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.

scholarly journals Bionic design and test of polycrystalline diamond compact bit for hard rock drilling in coal mine

2020 ◽  
Vol 12 (5) ◽  
pp. 168781402092318
Author(s):  
Chuanliu Wang
Keyword(s):  
Service Life ◽  
Coal Mine ◽  
Hard Rock ◽  
Polycrystalline Diamond ◽  
Research Direction ◽  
Future Research ◽  
Test Results ◽  
Bionic Design ◽  
Rock Drilling ◽  
Polycrystalline Diamond Compact

For hard rock drilling in coal mine, the drilling efficiency and service life of polycrystalline diamond compact bit are very low. To overcome these shortcomings, the bionic technology is applied to the design and processing of polycrystalline diamond compact bit. The bit body and polycrystalline diamond compact cutter are designed as bionic structures, and the test of the bionic polycrystalline diamond compact bit is carried out. Test results show that, when drilling in fine sandstone with hardness greater than 9, the performance of the bionic polycrystalline diamond compact bit is significantly improved. Comparing with the Φ113-mm concave polycrystalline diamond compact bit, the service life and drilling efficiency of the A-type bionic polycrystalline diamond compact bit increase by 54% and 230%, respectively, the service life and drilling efficiency of the B-type bionic polycrystalline diamond compact bit increase by 345% and 204%, respectively, which show that the bionic design of polycrystalline diamond compact bit can provide a new research idea for hard rock drilling in coal mine. Also the test results indicate that, when processing the bionic polycrystalline diamond compact cutter, the linear cutting process will cause thermal damage to the diamond layer of polycrystalline diamond compact cutter, while the cold grinding process shows higher comprehensive performance, therefore the one-time synthesis of bionic polycrystalline diamond compact cutter is the future research direction.

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.

Design front rake angle of PDC bit based on SolidWorks simulation method

2016 ◽  
Vol 1 (3) ◽  
pp. 627 ◽  
Author(s):  
Xiaoming HAN ◽  
Chenxu LUO ◽  
Xingyu HAN
Keyword(s):  
Hard Rock ◽  
Simulation Analysis ◽  
Soft Rock ◽  
Polycrystalline Diamond ◽  
Simulation Method ◽  
Rake Angle ◽  
Element Simulation ◽  
Pdc Bit ◽  
Coal Rock ◽  
Polycrystalline Diamond Compact

<span lang="EN-US">In order to solve the bit front rake angle parameter selection problem of under different coal rock, it is proposed in polycrystalline diamond compact no core bit as the research object, and established a bit compact two-dimensional stress model of cutting teeth. The result shows that the front rake angle is the factor of cutting force and the drilling efficiency. Application of SolidWorks simulation carries out the finite element simulation analysis respectively to different front rake angle of bit model under the condition of soft rock and hard rock. Form the simulation it concludes that under the condition of soft rock and hard rock, the optimal front rake angle is 10° and 15° respectively. It is obtained that the strength of the bit is largest and the life is longest on the best front rake angle of bit.</span>

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.

Drill Bit Failure Forensics using 2D Bit Images Captured at the Rig Site

2021 ◽  
Author(s):  
Pradeepkumar Ashok ◽  
Jian Chu ◽  
Ysabel Witt-Doerring ◽  
Zeyu Yan ◽  
Dongmei Chen ◽  
...  
Keyword(s):  
Image Processing ◽  
Polycrystalline Diamond ◽  
Sensor Data ◽  
Vibration Data ◽  
Damage And Failure ◽  
Root Cause ◽  
Pdc Bit ◽  
Cause Of Failure ◽  
The Individual ◽  
Bit Life

Abstract Identifying the root cause of damage of a pulled bit as soon as possible will aid preparation for future bit runs. Today, such bit damage analyses are often anecdotal, subjective and error-prone. The objective of this project was to develop a software algorithm to automatically analyze 2D bit images taken at the rig site, and to quickly identify the root cause of bit damage and failure. A labelled dataset was first created whereby the damage seen in bit photos was associated with the appropriate root cause of failure. Particular attention was given to the radial position of the cutters that were damaged. Using the 2D bit images (which can be obtained at the rig site), a convolutional neural network along with other image processing techniques were used to identify the individual cutters, their position on the bit, the degree of wear on each cutter. A classifier was then built to directly identify root cause of failure from these images. This work utilized a large dataset of wells which included multiple bit images, surface sensor data, downhole vibration data, and offset well rock strength information. This dataset helped relate the type of dysfunction as seen in the downhole and surface sensor data to the damage seen on the bit. This dataset however only covered some types of dysfunctions and some types of bit damage. It was therefore augmented with bit images for which the type of failure was determined through analysis by a subject- matter expert. A classifier was subsequently developed which properly identified the root causes of failure when the bit photo quality met certain minimum standards. One key observation was that bit images are not always captured appropriately, and this reduces the accuracy of the method. The automated forensics approach to Polycrystalline Diamond Compact (PDC) bit damage root cause analysis described in this paper can be performed using 2D bit photos that can be easily captured on a phone or camera at the rig site. By identifying the potential root causes of PDC damage through image processing, drilling parameters and bit selection can be optimized to prolong future bit life. The algorithm also enables uniformity in bit analysis across a company's operations, as well as the standardization of the process.

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.

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