Interaction Effect of Depth of Cut, Back Rake Angle and Rock Properties on Temperature of Single Polycrystalline Diamond Compact Cutter

A high pressure single polycrystalline diamond compact (PDC) cutter testing facility was used to investigate the effect of five factors on PDC cutter performance on Alabama marble. The factors include: depth of cut (DOC), rotary speed, back rake angle, side rake angle, and confining (wellbore) pressure. The performance is quantified by two parameters: mechanical specific energy (MSE) and friction angle. Fractional factorial design of experiments methodology was used to design the experiments, enabling detection of potential interactions between factors. Results show that, in the range tested, the only statistically significant factor affecting the MSE is DOC. In other words, DOC's influence is predominant and it can mask the effect of all the other factors. These results could have applications in real time pore pressure detection. Further, the results show that back rake angle is the most statistically significant factor in friction angle. Side rake angle and depth of cut also affect the friction angle, but in a relatively unimportant manner. The MSE–DOC behavior is explained and modeled by cutter edge–groove friction and the circular cutter shape. It is speculated that high cutter edge friction overwhelms the actual cutting process. A comparison of five currently present models in the literature with these results is presented and the conclusion is that the future PDC cutter models should digress from the traditional shear failure plane models.

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

10.2523/iptc-21457-ms ◽

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

Journal of Energy Resources Technology ◽

10.1115/1.4050340 ◽

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.

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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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The Effect on Cutting Tool Forces of Pre-Weakening a Rock Surface by Waterjet Kerfing

Journal of Engineering for Industry ◽

10.1115/1.3188727 ◽

1989 ◽

Vol 111 (1) ◽

pp. 1-6

Author(s):

J. E. Geier ◽

M. Hood

Keyword(s):

Unit Volume ◽

Cutting Tool ◽

Normal Force ◽

Mechanical Energy ◽

Polycrystalline Diamond ◽

Empirical Models ◽

Depth Of Cut ◽

Rock Surface ◽

Mechanical Specific Energy ◽

Polycrystalline Diamond Compact

Empirical models are developed to describe the influence on the cutting process of preweakening a rock, by cutting a series of parallel kerfs in the surface with high pressure waterjets, prior to excavating the rock with a polycrystalline diamond compact (PDC) drag bit. These models show that both the bit cutting force and the bit normal force are reduced substantially (by as much as a factor of four) when the spacing and the depth of the kerfs is appropriate to the depth of cut taken by the bit. The mechanical specific energy, or the mechanical energy applied to the bit to excavate a unit volume of rock, is also reduced dramatically when the rock is prekerfed.

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

Journal of Manufacturing Science and Engineering ◽

10.1115/1.4007468 ◽

2012 ◽

Vol 134 (6) ◽

Cited By ~ 20

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.

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

Journal of Energy Resources Technology ◽

10.1115/1.2905960 ◽

1992 ◽

Vol 114 (4) ◽

pp. 323-331 ◽

Cited By ~ 5

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

Journal of Energy Resources Technology ◽

10.1115/1.4003168 ◽

2010 ◽

Vol 132 (4) ◽

Cited By ~ 33

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.

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3D Numerical Simulation of Rock Cutting of an Innovative Non-Planar Face PDC Cutter and Experimental Verification

Applied Sciences ◽

10.3390/app9204372 ◽

2019 ◽

Vol 9 (20) ◽

pp. 4372 ◽

Cited By ~ 1

Author(s):

Jianxun Liu ◽

Hualin Zheng ◽

Yuchun Kuang ◽

Han Xie ◽

Chao Qin

Keyword(s):

Polycrystalline Diamond ◽

Element Model ◽

Rake Angle ◽

Rock Breaking ◽

Field Application ◽

Planar Structure ◽

Rock Properties ◽

Cutting Depth ◽

Rotational Angle ◽

Breaking Mechanism

The low rock breaking efficiency of conventional polycrystalline diamond compact (PDC) bits in hard abrasive formations prompts the development of PDC cutting elements from the planar structure to the non-planar structure. As an innovative non-planar cutter, the design and research of the three-ridged diamond element (3-RDE) cutter is still in its infancy, and its rock breaking mechanism and laws are not yet clear. In this paper, a three-dimensional (3D) finite element model of dynamic rock breaking with 3-RDE cutter has been established. The accuracy of the numerical model was verified by experimental data. Then, the difference of rock breaking mechanism between 3-RDE cutter and conventional cutter was studied. The effects of back-rake angle, cutting depth, rotational angle, and rock properties on rock breaking efficiency were also analyzed. The results show that, unlike the conventional PDC shear rock breaking cutter, the 3-RDE cutter breaks rock mainly by crushing and shearing, and the rock breaking efficiency is higher. A small back-rake angle and reasonable cutting depth contribute to improving the rock breaking efficiency; the existence of rotational angle is not conductive to the rock breaking. The field application shows that compared with the conventional cutter, the 3-RDE cutter is easier to penetrate into the formation, and is more stable with less torque required. The research results can be of benefit to the design and manufacture of 3-RDE PDC bits.

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