Baseline Development of Rock Anisotropy Investigation Utilizing Empirical Relationships Between Oriented Physical and Mechanical Measurements and Drilling Performance

Author(s):  
Abdelsalam N. Abugharara ◽  
Abourawi M. Alwaar ◽  
Stephen D. Butt ◽  
Charles A. Hurich

This paper describes a baseline investigation to confirm the isotropy of rocks material through physical and mechanical measurements followed by oriented drilling. This baseline is intended to evaluate drilling experiments in anisotropic rock materials to determine the significance of the anisotropy on drilling performance. The conducted tests include oriented measurements of compressional and shear wave velocities (Vp and Vs, respectively), density, Elastic Moduli, Point Load Strength Index (PLI), Indirect Tensile (IT) strength, and Unconfined Compressive Strength (UCS). The oriented laboratory drilling experiments were conducted under various pump flow rates and several weights on bit (WOB). In this work, an isotropic rock like material (RLM) was developed using Portland cement and fine-grained aggregate. The tested RLM specimens were of medium strength of ∼50 MPa. The RLM samples were cored in different orientations and then, tested and drilled according to these orientations. (e.g. 0°, 45° and 90°, representing horizontal, diagonal and vertical directions, respectively). Two main sets of lab tests were performed including pre-drilling and drilling tests. For the pre-drilling lab experiments, two main sets of tests were conducted to determine the physical and mechanical properties of samples (as outlined above) including PLI, IT, UCS, Vp, Vs, density and corresponding isotropic Dynamic Elastic Moduli. For the drilling tests, a vertical lab scale drilling rig was used with a 35 mm dual-cutter Polycrystalline Diamond Compact “PDC” bit. The drilling parameters involved were flow rates, nominal rotary speed of 300 rpm, and various WOB under atmospheric pressure. The relationships between the drilling data were analyzed including drilling rate of penetration (ROP), depth of cut (DOC), and corresponding effective WOB. The results of all mechanical, physical and drilling measurements and tests show consistent values indicating the isotropy of the tested rock material. This consistency verifies that the drilling tests are free of bias associated with drilling orientation.

Author(s):  
Abdelsalam N. Abugharara ◽  
Charles A. Hurich ◽  
John Molgaard ◽  
Stephen D. Butt

The influence of shale anisotropy orientation on shale drilling performance has been studied using a new laboratory procedure. This procedure includes drilling and testing three sets of shale samples in different orientations from a single rock sample. Shale samples of different types were collected from outcrops located at Conception Bay South (CBS) in Newfoundland, Canada. For predrilling tests, oriented physical and mechanical measurements on each type of shale were conducted on the same rocks that will be drilled later. For drilling tests, three sets of tests were conducted. Each set was in a different orientation, corresponding to those in the physical and mechanical measurements. Each set was conducted under the same drilling parameters of pressure, flow rate (FR), and weight on bit (WOB) using a fully instrumented laboratory scale drilling rig. Two different types of drill bits were used, including a 35 mm dual cutter PDC bit and a 25.4 mm diamond coring bit. The drilling data was analyzed by constructing relationships between drilling rate of penetration (ROP) versus orientation (i.e. 0°, 45°, or 90°). The analysis also included relationships between WOB and bit cutter Depth of Cut (DOC), Revolution Per Minute (RPM), and Torque (TRQ). All the above relations were evaluated as a function of shale bedding orientation. This evaluation can assist in understanding the influence of shale anisotropy on oriented drilling. Details of the conducted tests and results are reported.


2019 ◽  
Vol 141 (10) ◽  
Author(s):  
A. N. Abugharara ◽  
Bashir Mohamed ◽  
C. Hurich ◽  
J. Molgaard ◽  
S. D. Butt

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.


Author(s):  
Abdelsalam N. Abugharara ◽  
Charles A. Hurich ◽  
John Molgaard ◽  
Stephen D. Butt

A laboratory procedure has been developed to evaluate the anisotropy of Rock Like Material (RLM), granite, red shale, and green shale. This procedure involves detailed anisotropy evaluation steps through implementing circular ultrasonic wave velocity measurements, representing physical measurement and multiple drilling parameters (MDP), representing drilling performance. The physical tests involved circular pattern measurements of compressional and shear wave velocities, VP and VS, respectively. The drilling tests involved drilling samples of each rock in different a 25.4 mm Diamond Coring bit. The MDP included the study of the variations of Rate of Penetration (ROP), bit cutter Depth of Cut (DOC), Revolution Per Minute (RPM), and Torque (TRQ). The MPD were studied as function of orientations under atmospheric pressure. In addition to the physical and drilling evaluation, mechanical tests, such as Oriented Unconfined Compressive Strength (OUCS) were also used in rock anisotropy evaluation. Concrete with fine aggregate and Portland cement is used as RLM for much of the laboratory work. This material was cast into cylinders measuring 101.6 mm by 152.4 mm and 203.2 mm by 203.2 mm, from which NQ; 47.6mm core samples were taken. Coring was performed in three main orientations including 0°, 45°, and 90°. Characterization tests were performed on the RLM cores as they were conducted on the natural rock that included granite and red shale as isotropic and vertical transverse isotropic rocks, respectively. A fully instrumented lab-scale rotary drilling rig was used in conducting the drilling experiments. Details on the strategy for the tests on the anisotropy evaluation with results from laboratory work on natural rocks and RLM are reported. Result of the effect of shale anisotropy orientation on the drilling parameters that influence ROP as means of anisotropy evaluation are also, reported.


2021 ◽  
pp. 200-206
Author(s):  
I.N. Sedinin ◽  
V.F. Makarov

It is considered the complex of operations of the technological process for the heat treatment of steel 95X18-Sh, as a result of which the material of the samples increases the hardness to 59...61 HRC, and also improves the physical and mechanical properties. A full-scale full factorial experiment of face milling of samples was carried out using the method of mathematical planning. In the experiments, a high-precision machine and a carbide cutting tool were used. To calculate the values of the roughness function, the following are taken as independent variables: cutting speed, feed per tooth and depth of cut. In order to determine the coefficients of the linear equation, a central compositional orthogonal plan of the second order for three factors was used. A matrix of levels of variation of independent variable factors and a matrix of experiment planning were compiled. A regression analysis of the obtained experimental statistical data was carried out using the Microsoft Excel, Statistica and Wolfram Alpha programs. As a result of the calculations, a mathematical model of the roughness of the machined surface and optimal cutting conditions were determined.


2012 ◽  
Author(s):  
R. J. Talib ◽  
S. Saad ◽  
M. R. M. Toff ◽  
A. H. Hashim

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


Author(s):  
Daiyan Ahmed ◽  
Yingjian Xiao ◽  
Jeronimo de Moura ◽  
Stephen D. Butt

Abstract Optimum production from vein-type deposits requires the Narrow Vein Mining (NVM) process where excavation is accomplished by drilling larger diameter holes. To drill into the veins to successfully extract the ore deposits, a conventional rotary drilling rig is mounted on the ground. These operations are generally conducted by drilling a pilot hole in a narrow vein followed by a hole widening operation. Initially, a pilot hole is drilled for exploration purposes, to guide the larger diameter hole and to control the trajectory, and the next step in the excavation is progressed by hole widening operation. Drilling cutting properties, such as particle size distribution, volume, and shape may expose a significant drilling problem or may provide justification for performance enhancement decisions. In this study, a laboratory hole widening drilling process performance was evaluated by drilling cutting analysis. Drill-off Tests (DOT) were conducted in the Drilling Technology Laboratory (DTL) by dint of a Small Drilling Simulator (SDS) to generate the drilling parameters and to collect the cuttings. Different drilling operations were assessed based on Rate of Penetration (ROP), Weight on Bit (WOB), Rotation per Minute (RPM), Mechanical Specific Energy (MSE) and Drilling Efficiency (DE). A conducive schedule for achieving the objectives was developed, in addition to cuttings for further interpretation. A comprehensive study for the hole widening operation was conducted by involving intensive drilling cutting analysis, drilling parameters, and drilling performance leading to recommendations for full-scale drilling operations.


RSC Advances ◽  
2015 ◽  
Vol 5 (75) ◽  
pp. 60723-60735 ◽  
Author(s):  
Andrew J. Gravelle ◽  
Shai Barbut ◽  
Alejandro G. Marangoni

The mechanical properties of glass and wax particle-filled myofibrillar protein gels were characterized based on filler size and surface effects. Increases in elastic moduli were explained using established models describing particle-filled networks.


2021 ◽  
pp. 1-17
Author(s):  
Abbas Roohi ◽  
Rahman Ashena ◽  
Gerhard Thonhauser ◽  
Thomas Finkbeiner ◽  
Laurent Gerbaud ◽  
...  

Abstract This work investigates the drilling performance by reaming while drilling (RWD) using a dual-body bit and compared it with conventional drilling by a standard drilling bit. The dual-body bit consisted of a 2.45-in pilot bit located at a short distance ahead of a 2.47*3.97-in reamer. Conducting a series of drilling experiments at a simulation drilling rig with full monitoring sensors, we further studied the drilling performance as a function of the distance between the pilot bit and the reamer which affect mud diffusion and the resultant change in pore pressure and stress. A method was devised to eliminate the drill-string vibration and its effect on the drilling performance and the energy consumed. The mechanical specific energy (MSE) calculated for each case was considered as a drilling performance indicator. Using two laboratory experiments as well as analytical thermo-poro-elastic calculations of the Mechanical Specific Energy (MSE), the MSE changes were monitored and recorded. Comparison of this drilling performance indicator was used in both the RWD and the conventional drilling assembly to analyze the effect of RWD. Based on the results, with increasing the distance between the pilot bit and reamer, there is an increase in improvement of drilling performance in terms of MSE reduction. The best drilling performance indicator (MSE reduction of 84%) was observed with the distance between the pilot bit and the reamer of 43.3 cm. This is considered a novel finding in reaming while drilling.


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