Issues in Polycrystalline Diamond Compact Cutter–Rock Interaction From a Metal Machining Point of View—Part I: Temperature, Stresses, and Forces

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

This paper provides a comprehensive review of the literature that deals with issues surrounding the polycrystalline diamond compact (PDC) cutter–rock interface during rock cutting/drilling processes. The paper is separated into two parts addressing eight significant issues: Part I deals with fundamental issues associated with temperature/stress distribution and loading force prediction, while Part II focuses on issues related to PDC cutter/bit performance, wear and other failure phenomena, rock removal mechanism and cutting theory, rock properties, and numerical modeling of cutter–rock interaction. Experimental, analytical, and numerical methods are included into the investigation of the above-mentioned eight issues. Relevant concepts from metal cutting, micromachining, and other machining processes are also introduced to provide important insights and draw parallels between these interrelated fields.

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.

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.

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.

Drilling Action of Roller-Cone Bits: Modeling and Experimental Validation

2010 ◽  
Vol 132 (4) ◽  
Author(s):  
Luiz F. P. Franca
Keyword(s):  
Polycrystalline Diamond ◽  
Quantitative Information ◽  
Rock Properties ◽  
Drilling Rig ◽  
Proposed Model ◽  
Theoretical Predictions ◽  
Weight On Bit ◽  
Torque On Bit ◽  
Polycrystalline Diamond Compact ◽  
Potential Use

This paper presents a new model of the drilling response of roller-cone bits. First, a set of relations between the weight-on-bit W, the torque-on-bit T, the rate of penetration V, and the angular velocity Ω is established in the spirit of the model developed for polycrystalline diamond compact (PDC) bits. In contrast to models that depend on a precise description of the bit, the drilling response is investigated by lumping the effect of the bit geometry into a few parameters and on averaging the drilling quantities (W,T,V,Ω) over at least one revolution of the bit. Within the framework of the model, quantitative information from drilling data related to rock properties, bit conditions, and drilling efficiency can be extracted. Finally, a series of laboratory tests at atmospheric pressure conducted with an in-house designed drilling rig, together with published experimental data, is used to evaluate the proposed model. The good match between the experimental results and the theoretical predictions are promising in regard to the potential use of this model to investigate the drilling response of roller-cone bits.

Computer-Aided Process Planning and Manufacturing

2009 ◽  
pp. 54-74
Author(s):  
Xun Xu
Keyword(s):  
Process Planning ◽  
Metal Cutting ◽  
Point Of View ◽  
General Point ◽  
Machining Processes ◽  
Computer Aided Manufacturing ◽  
Computer Aided Process Planning ◽  
Computer Aided ◽  
Planning Methods ◽  
Cutting Processes

Products and their components are designed to perform certain functions. Design specifi- cations ensure the functionality aspects. The task in manufacturing is then to produce the components that meet the design specifications. The components are in turn assembled into the final products. When computers are used to assist the process planning and manufacturing activities, multiple benefits can be had. The related technologies are known as computer-aided process planning and computer-aided manufacturing. Often, they are not separable and are therefore discussed in tandem in this chapter. It should be emphasized that process planning is not only for metal-cutting processes. We need process planning for many other manufacturing processes such as casting, forging, sheet metal forming, compositesz and ceramic fabrication. In this chapter, the basic steps of developing a process plan are explained. There are two approaches to carrying out process planning tasks—manual experience-based method and computer-aided process planning method. The focus is on two computer-aided process planning methods, the variant approach, and generative approach. These discussions on process planning have been limited to machining processes. The topic of computer-aided manufacturing, on the other hand, is discussed with a more general point of view. A fictitious CAM plant is presented and some of the key aspects of CAM in a manufacturing system are discussed. A more specific version of CAM (i.e. computer numerical control) will be covered in Chapters VIII and IX.

Dynamical Analysis of Drill Bit With Ultrasonic Vibration

2015 ◽  
Author(s):  
Dapeng Zhao ◽  
Sigbjørn Sangesland
Keyword(s):  
Ultrasonic Vibration ◽  
Reaction Force ◽  
Polycrystalline Diamond ◽  
Dynamical Analysis ◽  
Contact Friction ◽  
Rock Interaction ◽  
Drill Bits ◽  
Mass Spring Model ◽  
Mass Spring ◽  
Polycrystalline Diamond Compact

Based on the bit-rock interaction laws, a simple nonlinear 2-dofs mass-spring model is developed to analyze the dynamic cutting process with normal ultrasonic vibration excitation. The study presents a single cutter used in Polycrystalline-Diamond-Compact (PDC) drill bits. Using the 4th Runge-Kutta’s algorithm, numerical simulation found that ultrasonic vibration-induced contact deflection and even loss of contact. The contact friction between the rock and wear-flat (wear surface), which relates to the reaction force, is therefore reduced. This will reduce the wear on the cutter and the force needed to cut the rock. This indicates that the average reduction of friction induced by ultrasonic vibration can be explained by decreasing the average normal force on the cutter-rock wear-flat, rather than changing the friction coefficient.

Advantages of an LQR Controller for Stick-Slip and Bit-Bounce Mitigation in an Oilwell Drillstring

2012 ◽  
Author(s):  
Md. Mejbahul Sarker ◽  
D. Geoff Rideout ◽  
Stephen D. Butt
Keyword(s):  
Torsional Vibration ◽  
Graph Model ◽  
Polycrystalline Diamond ◽  
Linear Quadratic Regulator ◽  
Linear Quadratic ◽  
Stick Slip ◽  
Rock Interaction ◽  
Lqr Controller ◽  
Vibration Fatigue ◽  
Polycrystalline Diamond Compact

Failure of oilwell drillstrings is very costly in terms of money and time. There are many reasons for drillstring failure, such as vibration, fatigue, and buckling. Stick-slip vibration has received considerable attention in recent years with increasing use of polycrystalline diamond compact (PDC) bits in harder formations, and has motivated extensive research on this type of drillstring vibration. This paper addresses the advantages of a linear quadratic regulator (LQR) controller, compared to a spring-damper isolator, for stick-slip and bit-bounce mitigation in an oilwell drillstring. A bond graph model of a drillstring has been used for simulation that predicts axial vibration, torsional vibration, and coupling between axial and torsional vibration due to bit-rock interaction.

Dynamics of the processes in metal machining

1998 ◽  
Vol 2 ◽  
pp. 115-122
Author(s):  
Donatas Švitra ◽  
Jolanta Janutėnienė
Keyword(s):  
High Frequency ◽  
Machine Tools ◽  
Metal Cutting ◽  
Cutting Tool ◽  
Low Frequency ◽  
Metal Cutting Machine ◽  
Cutting Machine ◽  
Metal Machining

In the practice of processing of metals by cutting it is necessary to overcome the vibration of the cutting tool, the processed detail and units of the machine tool. These vibrations in many cases are an obstacle to increase the productivity and quality of treatment of details on metal-cutting machine tools. Vibration at cutting of metals is a very diverse phenomenon due to both it’s nature and the form of oscillatory motion. The most general classification of vibrations at cutting is a division them into forced vibration and autovibrations. The most difficult to remove and poorly investigated are the autovibrations, i.e. vibrations arising at the absence of external periodic forces. The autovibrations, stipulated by the process of cutting on metalcutting machine are of two types: the low-frequency autovibrations and high-frequency autovibrations. When the low-frequency autovibration there appear, the cutting process ought to be terminated and the cause of the vibrations eliminated. Otherwise, there is a danger of a break of both machine and tool. In the case of high-frequency vibration the machine operates apparently quiently, but the processed surface feature small-sized roughness. The frequency of autovibrations can reach 5000 Hz and more.

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