Analysis of Surface Set Diamond Bit Performance

1969 ◽  
Vol 9 (03) ◽  
pp. 301-310 ◽  
Author(s):  
D.S. Rowley ◽  
F.C. Appl
Keyword(s):  
Drilling Fluid ◽  
Complete Analysis ◽  
Depth Of Cut ◽  
Rigid Plastic ◽  
Rock Formation ◽  
Drilling Performance ◽  
Cutting Surface ◽  
The Individual ◽  
Drilling Conditions ◽  
Diamond Bit

Abstract With, the assumption of perfect cleaning, a theory of the drilling performance of surface set diamond bits has been developed. The analysis is based on the previously developed theory of the cutting action of a single diamond, in which it was assumed that rock behavior during cutting may be approximated by that of a rigid-plastic, Coulomb material. With specified drilling conditions and rock formation, expressions for bit torque and bit weight are obtained in terms of bit penetration rate. Expressions also are obtained for the depths of cut of the diamonds. Note that depth of cut and diamond cutting force vary considerably over the cutting surface of the bit. Theoretical results are compared with experimental results for full hole bits and core bits. The agreement is reasonable. Introduction A theoretical analysis of single diamond cutting action on rock has been presented. Equations were established for the stress distribution on the cutting surface of the diamond, for the normal and the tangential cutting forces, and for the chip volume removed by the diamond. These relations were obtained by assuming that the principal, mode of material removal is by "ploughing", and that the rock formation may be approximated by a rigid-plastic, Coulomb material. It is pertinent to consider the drilling performance of a surface set diamond bit, since the over-all performance is determined by the total effect of the individual diamonds on the cutting surface of the bit. A complete analysis of surface set diamond bit performance should take into account the interaction performance should take into account the interaction of the drilling fluid with the mechanics of the cutting action. All material loosened by the diamonds must be carried away by the drilling fluid as it flows between the cutting face of the bit and the rock being cut. The geometry of the clearance between bit and rock is dependent on the diamond catting action as well as the bit geometry. Still there are many factors related to chip generation and removal. that are not understood, and hence, a complete analysis of bit performance including bit hydraulics effects has not been attempted. The present study relates primarily to the mechanics of cutting. It will be assumed that all of the material removed by the diamonds is immediately flushed away by the drilling fluid. The performance of a diamond bit will be determined for conditions of "perfect cleaning". Theoretical results for penetration rate will, therefore, correspond to the upper limit insofar as cleaning is concerned. Using the previous theory of cutting action, one important step remains in order to determine diamond bit performance. The depth of cut of the diamonds must be determined in terms of bit geometry and drilling rate. Most bits have a relatively large number of diamonds spaced rather closely, together. Various spacing patterns are used. However, irregularities in diamond shape and variation due to manufacturing procedures result in deviations that are as large or procedures result in deviations that are as large or larger than the average depth of cut of the individual diamonds. On a new bit it is probable that there are some diamonds that do not cut at all. It seems impractical to attempt to determine the depth of cut of each individual diamond. Statistical treatment of the depth of cut is perhaps the most desirable. Since there is a large number of cutting points, it has been assumed that the performance of the bit as a whole does not depend significantly on the exact nature of the variation in depth of cut and spacing at each radius. We assumed that at any given radius on the bit cutting surface, the diamonds are either randomly spaced or uniformly spaced and that the diamonds along the circumference at any given radius share the work equally. Also, we assume that the drilling conditions and the rock formation remain constant and that steady-state conditions prevail. SPEJ P. 501

Mathematical Model of the Diamond-Bit Drilling Process and Its Practical Application

1982 ◽  
Vol 22 (06) ◽  
pp. 911-922 ◽  
Author(s):  
Malgorzata B. Ziaja ◽  
Stefan Miska
Keyword(s):  
Penetration Rate ◽  
Drilling Fluid ◽  
Active Surface ◽  
Rock Properties ◽  
Depth Of Cut ◽  
Drilling Process ◽  
Diamond Cutting ◽  
Rate Of Penetration ◽  
Drilling Performance ◽  
Diamond Bit

Abstract With several limiting assumptions, a mathematical model of the diamond-bit drilling, process has been developed. The model represented by an instantaneous rate-of-penetration equation takes into account the reduction in penetration rate during drilling resulting from bit wear. The model has been tested both under laboratory and under field conditions. The comparison of the theoretical and experimental results has shown reasonable agreement. A method for estimating rock properties also has been established. Using this method, we can find the so-called index of rock strength and the index of rock abrasiveness. Introduction Several published studies concerned with diamond-bit drilling report on rock properties and drillability. drilling fluid additives, diamond wear, and drilling performance theories. Among the factors, that affect diamond-bit drilling performance, the type of formation to be drilled is of utmost importance since it significantly affects the type of bit, the drilling practices. and subsequently the rate of penetration and the drilling cost. The nature of the formation is also one of the main factors in planning deep wells, fracture jobs, mud and cement technologies, etc. For rock properties evaluation as well as for selection of proper drilling practices, several descriptions of the diamond-bit drilling process have been developed. The relevant literature is extensive and is not reviewed in this paper. The objective of this paper is to describe the diamondbit drilling model for surface-set diamond core bits and its application to determining the index of formation strength and the index of formation abrasiveness. The main difference between our model and the models known in literature is that we consider the effect of friction between the diamond cutting surfaces and the rock. A decrease in penetration rate is observed if the drilling parameters, are constant and if the formation is macroscopohomogeneous. Drilling Model The drilling model for a surface-set diamond core bit is subjected to the following limiting assumptions.Rock behavior during cutting with a single diamond may be approximated by a rigid Coulomb plastic material.The active surface of the bit is flat, and diamonds are spherical with diameter. d.The cross-sectional area of the chip formed by a single diamond is equal to the diamond cutting surface and can be established by geometry.During drilling, the neighboring diamonds work together to make a uniform depth of cut (Fig. 1).A number of diamonds forming one equivalent blade have to provide it uniform depth of cut from the inner to the outer diameter of the diamond core bit. so the bit is modeled to be a combination of several equivalent blades (Fig. 2).The diamond distribution technique provides uniform radial coverage that results in equally loaded cutting diamonds.Individual cutting diamonds perform some work that results from the friction between the rock and the diamond.Bit wear is assumed to be gradual while drilling is in progress. Under the preceding assumptions we may state that the drilling rate of the surface-set diamond core bit is a function only of weight on bit (WOB), rotary speed, average density of the diamonds on the bit's active surface, diamond size, core-bit diameters, rock properties, and degree of diamond dullness. The effects of flow rate, differential pressure, hydraulic lift, drilling fluid properties. and drillstring dynamics are ignored. According to Peterson, the penetration rate of the diamond bit, after some modifications, can be described by the following simplified equation. (1) This equation does not include the effect of diamond wear and hence pertains to unworn bits or to when bit dullness is negligible. SPEJ P. 911^

Experimental Investigation of the Effect of Shale Anisotropy Orientation on the Main Drilling Parameters Influencing Oriented Drilling Performance in Shale

2019 ◽  
Vol 141 (10) ◽  
Author(s):  
A. N. Abugharara ◽  
Bashir Mohamed ◽  
C. Hurich ◽  
J. Molgaard ◽  
S. D. Butt
Keyword(s):  
Drilling Fluid ◽  
Polycrystalline Diamond ◽  
Bedding Plane ◽  
Depth Of Cut ◽  
Fine Aggregate ◽  
Drilling Rig ◽  
Drilling Performance ◽  
Bedding Planes ◽  
Weight On Bit ◽  
Shale Anisotropy

The influence of shale anisotropy and orientation on shale drilling performance was studied with an instrumented laboratory drilling rig with a 38.1-mm dual-cutter polycrystalline diamond compact (PDC) bit, operating at a nominally fixed rotational speed with a constant rate of flow of drilling fluid—water. However, the rate of rotation (rpm) was affected by the weight on bit (WOB), as was the torque (TRQ) produced. The WOB also affected the depth of cut (DOC). All these variables, WOB, rpm, TRQ, and DOC, were monitored dynamically, for example, rpm with a resolution of one-third of a revolution (samples at time intervals of 0.07 s.) The shale studied was from Newfoundland and was compared with similar tests on granite, also from a local site. Similar tests were also conducted on the concrete made with fine aggregate, used as “rock-like material” (RLM). The shale samples were embedded (laterally confined) in the concrete while drilled in directions perpendicular, parallel, and at 45 deg orientations to bedding planes. Cores were produced from all three materials in several directions for the determination of oriented physical properties derived from ultrasonic testing and oriented unconfined compressive strength (OUCS). In the case of shale, directions were set relative to the bedding. In this study, both primary (or compression) velocity Vp and shear ultrasonic velocity Vs were found to vary with orientation on the local shale samples cored parallel to bedding planes, while Vp and Vs varied, but only slightly, with orientation in tests on granite and RLM. The OUCS data for shale, published elsewhere, support the OUCS theory of this work. The OUCS is high perpendicular and parallel to shale bedding, and is low oblique to shale bedding. Correlations were found between the test parameters determined from the drilling tests on local shale. As expected, ROP, DOC, and TRQ increase with increasing WOB, while there are inverse relationships between ROP, DOC, and TRQ with rpm on the other hand. All these parameters vary with orientation to the bedding plane.

scholarly journals Complexes for continuous monitoring of drilling fluid parameters during drilling

2021 ◽  
Vol 6 (3) ◽  
pp. 144-151
Author(s):  
Sergey V. Lakhtionov ◽  
Ivan S. Chumakov ◽  
Sergey G. Filinkov ◽  
Dmitry M. Chukin ◽  
Evgeny N. Ishmetyev
Keyword(s):  
Continuous Monitoring ◽  
Drilling Fluid ◽  
Point Of View ◽  
Complete Analysis ◽  
Drilling Fluids ◽  
Automatic Mode ◽  
Design Values ◽  
Drilling Rigs ◽  
Almost All ◽  
Fluid Parameters

Background. The article provides an overview of existing complexes (units) for continuous monitoring of drilling fluid parameters in automatic mode. Aim. To justify the need to develop a complex (module) that will allow combining existing technologies and making a step forward in the field of process automation in terms of monitoring the parameters of drilling fluids. Materials and methods. In the current realities of well construction, the control of drilling fluid parameters on almost all drilling rigs operating on the territory of Russia (possibly with the exception of a few off shore projects) is carried out by the work of a solution engineer, usually a representative of a service company. The analysis of the parameters, depending on the number of personnel, the speed of penetration, the complexity or importance of the well, can be carried out from 2 to 6 times a day [1, 2]. This means a complete analysis, rather than monitoring the density and conditional viscosity, which can be measured by a representative of the drilling crew, for rapid response, and with greater frequency. Due to such a low measurement discreteness, there is a high probability of a significant deviation of the drilling fluid parameters from the design values. As a result, the probability of various complications, both geological and technological, increase significantly. Results. During the analysis of information from open sources, the most promising complexes (modules) from the point of view of application in the current conditions were identified, their positive and negative sides were evaluated. As a result of the conducted review of open sources, the most promising complexes (modules) in terms of application in the current conditions are identified, the positive and negative sides of the systems under consideration are displayed, and the need to develop a complex (module) that will combine all the best that is available today and make a qualitative step forward in the field of “peopleless” technologies used during drilling wells in terms of monitoring the parameters of drilling fluids is justified. Conclusions. The necessity of developing a complex (module) for automating processes in terms of monitoring the parameters of drilling fluids is justified.

Creative and Collaborative Engineering Delivers the Fastest Well in an Upper Miocene Reservoir, Shallow Water Field in The Gulf of Mexico

2021 ◽  
Author(s):  
Guillermo Caballero ◽  
Rajeswary Kandasamy ◽  
Omar E Vilchez ◽  
Luis Larrea ◽  
Francisco Santarini ◽  
...  
Keyword(s):  
Shallow Water ◽  
Service Providers ◽  
Planning Stage ◽  
Deep Dive ◽  
Upper Miocene ◽  
Drilling Performance ◽  
Water Field ◽  
Operational Practices ◽  
Drilling Conditions ◽  
Performance Results

Abstract This paper will detail the engineering strategies utilized from design and planning stage up to and beyond the field execution stage which resulted in drilling the fastest well in a shallow water field, delivering superior drilling performance and successfully targeting the Upper Miocene (tertiary) reservoir in Mexico. From the 9 wells drilled in this field, the fastest well "Y"-200 was drilled with an average well construction index of 179 m/day when compared to the field average of 54.2 m/day. This shallow water field manifests several specific challenges which include tough drilling conditions, fluid property and hydraulic management, logging constraints and critical selection of casing setting depths. In order to enhance the drilling performance results to lower costs and improve production timelines, the project team performed a deep-dive into the well challenges and engaged with multi disciplinary teams and service providers to brainstorm different design improvements and operational practices. By doing so, the performance accelerates the 6000 to 9000 bbls of initial production estimated per well. The application of these creative engineering ideas proves that change, when applied correctly can really create lasting and proven improvements in drilling performance.

SEM Observations on Wear Mechanism of TiN–Coated HSS Twist Drills When Drilling Mild Steel

2012 ◽  
Author(s):  
R. J. Talib ◽  
S. Saad ◽  
M. R. M. Toff ◽  
A. H. Hashim
Keyword(s):  
Mild Steel ◽  
Wear Mechanism ◽  
Performance Test ◽  
Steel Plate ◽  
High Speed Steel ◽  
Depth Of Cut ◽  
Twist Drill ◽  
Drilling Performance ◽  
Thermal Wear ◽  
Twist Drills

Dalam kajian ini, haus mekanikal Keluli Laju Tinggi (KLT) telah dikaji dengan menjalankan ujian prestasi gerudi ke atas bahan kerja diperbuat daripada keluli lembut. Salutan TiN ke atas HSS twist drills diperolehi dengan menggunakan kaedah bertindak balas frekuensi radio pemercitan magnetron yang mana dibangunkan secara dalaman. Ujian prestasi gerudi dijalankan pada kelajuan pusingan 1,600 psm, kadar suapan 20 mm/minit dengan kedalaman penggerudian 25 mm. Perubahan morfologi permukaan haus diperhatikan dengan menggunakan kaedah Kemikroskopan Imbasan Elektron (KEI). Keputusan morfologi menunjukkan mekanisme rekatan dan haba beroperasi semasa proses penggerudian. Kertas kerja ini juga akan membincangkan secara mendalam proses penjanaan mekanisme haus rekatan dan haba semasa penggerudian gerudi piuhan ke atas plat keluli lembut. Keputusan ujian prestasi gerudi menunjukkan salutan TiN terendap ke atas KLT gerudi piuhan telah meningkatkan umur gerudi melebihi dua kali ganda jika dibandingkan dengan gerudi yang tidak bersalut. Kata kunci: Gerudi KLT, KEI, mekanisme haus, rekatan, haba In this study, High Speed Steel (HSS) twist drills were investigated for mechanical wear by performing drilling test on the work piece of mild steel plate. TiN coatings onto the HSS twist drills were achieved by employing reactive radio frequency (r.f) magnetron sputtering technique, which was developed in–house. The drilling performance tests were set at a rotation speed of 1,600 rpm, feed rate of 20 mm/min, and depth of cut of 25 mm. The morphological changes of the wear surface were observed using Scanning Electron Microscopy (SEM). Results of morphological examination showed that the failure mechanisms in operation during drilling were found to be adhesive and thermal wear mechanism. This paper will also discuss explicitly the processes of adhesive and thermal wear mechanism generated during drilling of twist drill on mild steel plate. Results of drilling performance test showed that the TiN coating deposited on the HSS twist drill had improved drill life by more than 2 times as compared with uncoated drill. Key words: HSS drill, SEM, wear mechanism, adhesive, thermal

Comprehensive Hydromechanical Specific Energy Calculation for Drilling Efficiency

2014 ◽  
Vol 137 (1) ◽  
Author(s):  
Kshitij Mohan ◽  
Faraaz Adil ◽  
Robello Samuel
Keyword(s):  
Specific Energy ◽  
Drilling Fluid ◽  
Mechanical Energy ◽  
Energy Calculation ◽  
Energy Term ◽  
Modeling And Analysis ◽  
Mechanical Specific Energy ◽  
Available Energy ◽  
Jet Impact ◽  
Drilling Conditions

Over the last few years, different types of bits have been introduced to meet the challenges of steerable as well as rotary steerable systems; and it is imperative that bits be utilized optimally in these systems. As challenges increase with increasing depths, it becomes even more important for one to efficiently utilize the available energy (Robello, S., 2013, “Modeling and Analysis of Drillstring Vibration in Riserless Environment,” ASME J. Energy Res. Technol., 135(1), p. 013101). A new correlation identifying inefficient drilling conditions is presented in this paper. Mechanical specific energy (MSE) has been used to improve drilling rates, with mixed results. Hydro MSE (HMSE), which is introduced here, encompasses hydraulic as well as mechanical energy. HMSE quantifies the amount of energy required to drill a unit volume of rock and remove it from underneath the bit. HMSE includes axial, torsional, and hydraulic energy and is different from MSE because it includes a hydraulic term. The initial MSE correlation (Teale, R., 1965, “The Concept of Specific Energy in Rock Drilling,” Int. J. Rock Mech. Min. Sci., 2, pp. 57–73.) was modified to accommodate the new hydraulic term. This paper attempts to better model downhole drilling by introducing the hydraulic energy term in the MSE correlation by defining it as HMSE. While the majority of the drilling occurs because of the bit, it is a well-known fact that some drilling occurs due to the “jet impact impingement” caused by the drilling fluid as well. Experimental and field data presented in this paper show that HMSE can identify inefficient drilling conditions. The new hydraulic term included in the specific energy correlation is the key to correctly match the amount of energy required to drill and overcome the strength and stresses of formation being drilled. Also, this new term illustrates how much hydraulic energy is needed to drill faster when the mechanical energy (axial and torsional) is increased. The results also show the importance of including the bit hydraulic energy term into any specific energy analysis for drilling optimization. Field results reveal specific patterns for inefficient drilling conditions and also reveal a good correlation between calculated HMSE and the expected requirements for rock removal under existent conditions of stress at the bit face (Mohan, K., and Robello Samuel, F. A., 2009, “Tracking Drilling Efficiency Using Hydro-Mechanical Specific Energy,” SPE/IADC Drilling Conference and Exhibition, March 17–19, Amsterdam, The Netherlands, No. SPE 119421).

Drilling Fluid Impact Studies Show that Worker Health and the Environment Can Be Protected While Improving Drilling Performance

2018 ◽  
Author(s):  
Serena Lim ◽  
Delina Lyon ◽  
Graham Whale ◽  
Burnell Lee ◽  
Peter Boogaard ◽  
...  
Keyword(s):  
Drilling Fluid ◽  
Impact Studies ◽  
Drilling Performance ◽  
Worker Health

A Research on the SiCp Reinforcing Cu-Base Composite Material's Cutting Performance

2011 ◽  
Vol 175 ◽  
pp. 116-120
Author(s):  
Yi Ping Zhang ◽  
Yi Yi Tao ◽  
Zuo Jiang
Keyword(s):  
Composite Material ◽  
Electron Microscope ◽  
Cutting Force ◽  
Cutting Speed ◽  
Cutting Process ◽  
Depth Of Cut ◽  
Dislocation Theory ◽  
Cutting Surface ◽  
Base Composite ◽  
Electron Microscope Analysis

The relationships among the n, ap , and f of the SiCp /Cu composite material produced by powder metallurgy and extrusion have been investigated. The cutting force F of this material is also discussed in this paper by the measuring of the three cutting factors of n, ap, and f, applying the dislocation theory and the electron microscope analysis of the cutting surface and sub-surface. The differences are analyzed between the SiCp/Cu composite materials, QSn6-6-3. H59-1and the copper cutting surface and the sub-surface. The forming of mechanism, the function of SiCp in the cutting process and the influence on the cutting surface quality are also analyzed. This research has shown: because the SiCp particles prevent the dislocation moving, the dislocation groups are formed on the SiC/Cu interface, and the stress concentration is produced, the typical brittle separation appears in the SiC/Cu composite material cutting process. In addition, the cutting force increases with the depth of cut and feed increasing and decreases while the cutting speed increases.

Parameter Space Decomposition for Selection of the Axial and Radial Depth of Cut in Endmilling

2000 ◽  
Vol 123 (4) ◽  
pp. 654-664 ◽  
Author(s):  
J. A. Stori ◽  
P. K. Wright
Keyword(s):  
Case Studies ◽  
Parameter Space ◽  
Removal Rate ◽  
Cutting Parameters ◽  
Depth Of Cut ◽  
Radial Depth ◽  
Optimization Formulation ◽  
The Individual ◽  
Operating Points ◽  
Selection Of

Feeds and speeds for conventional endmilling operations have been empirically investigated and extensively tabulated 1. However, the selection of the geometric cutting parameters, the axial and radial depths of cut, remains an inexact science. Observation of mechanistic process simulation predictions reveal a relatively complex topology resulting from the multiple cutting flutes of conventional endmilling cutters as the axial and radial depths of cut are varied. A partitioning approach is presented that explicitly enumerates the transition events due to the entrance and exit of the individual cutting flutes. The resulting simplified optimization formulation permits selection of the axial and radial depth of cut that most efficiently satisfy critical simulation predictions such as maximum cutting force or form error. Case studies are presented illustrating the application of the method to select the cutting parameters in climb milling. The optimization objective in the case studies is to maximize the material removal rate, subject to the process induced constraints. Results suggest that operating at the extremes of either axial or radial engagement may in various instances be preferable to more conventional combinations of depth and width of cut. Certain regions of the parameter space are observed to be necessarily sub-optimal relative to particular planning constraints, while other regions are found to contain particularly attractive operating points.

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