PFC-2D Numerical Study of the Influence of Passive Vibration Assisted Rotary Drilling Tool (pVARD) on Drilling Performance Enhancement

2018 ◽  
Author(s):  
Abourawi Alwaar ◽  
Abdelsalam N. Abugharara ◽  
Stephen D. Butt
Keyword(s):  
Experimental Work ◽  
Performance Enhancement ◽  
Numerical Study ◽  
Particle Flow Code ◽  
Laboratory Work ◽  
Depth Of Cut ◽  
Rotary Drilling ◽  
Drilling Tool ◽  
Numerical Work ◽  
Drilling Performance

The objective of this work is to evaluate the influence of the implementing the downhole Passive Vibration Assisting Rotary Drilling (pVARD) Tool on enhancing drilling performance using a numerical study utilizing a Particle Flow Code (PFC-2D). The work is comprised of a numerical study of a simulation using the PFC-2D on an experimental work described in ARMA 15-492 (Rana et al, 2015). The numerical study was performed to validate the experimental work following the steps, procedure, and conditions performed in the laboratory work. The numerical study of the laboratory work involves not only the evaluation of drilling rate of penetration (ROP), but it also includes the Depth of Cut (DOC) of the bit cutters and the Mechanical Specific Energy (MSE). This numerical work also includes comparison study of drilling performance under various configurations of the pVARD tool, which represents a controlled downhole vibration against the rigid drilling configuration that represents the conventional rotary drilling. The pVARD configurations involves pVARD low spring compliance, medium spring compliance, and high spring compliance. The drilling output parameters of DOC, MSE, and ROP are then studied and analyzed in all pVARD and non-pVARD configurations. Likewise of the experimental work, the result of the numerical simulation approves the experimental work and it indicates the positive effect of utilizing the downhole pVARD on improving ROP. The drilling performance enhancement is also supported by the DOC and the MSE result.

Drilling Cutting Analysis to Assist Drilling Performance Evaluation in Hard Rock Hole Widening Operation

2020 ◽  
Author(s):  
Daiyan Ahmed ◽  
Yingjian Xiao ◽  
Jeronimo de Moura ◽  
Stephen D. Butt
Keyword(s):  
Performance Enhancement ◽  
Ore Deposits ◽  
Drilling Process ◽  
Rotary Drilling ◽  
Pilot Hole ◽  
Drilling Rig ◽  
Drilling Performance ◽  
Drilling Parameters ◽  
Weight On Bit ◽  
Drilling Operations

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.

The Dynamically Embedded Plate Anchor: Results From an Experimental and Numerical Study

2013 ◽  
Author(s):  
Conleth D. O’Loughlin ◽  
Anthony P. Blake ◽  
Dong Wang ◽  
Christophe Gaudin ◽  
Mark F. Randolph
Keyword(s):  
Experimental Work ◽  
Field Experiments ◽  
Numerical Study ◽  
Field Tests ◽  
Dry Weight ◽  
Numerical Work ◽  
Geotechnical Centrifuge ◽  
Plate Anchor ◽  
Plate Anchors ◽  
The Impact

Dynamically embedded plate anchors are rocket shaped anchors that penetrate to a target depth in the seabed by the kinetic energy obtained through free-fall. After embedment the central shaft is retrieved leaving the anchor flukes vertically embedded in the seabed. The flukes constitute the load bearing element as a plate anchor. This paper provides an overview of an experimental and numerical study undertaken to provide the first performance data for this anchor concept. The experimental work includes geotechnical centrifuge modelling and field tests using three different reduced anchor scales, whereas the numerical work focused on investigating anchor capacity for a rage of geometries, embedment depths and seabed conditions. The experimental work indicates that expected tip embedments are in the range 2 to 3.3 times the anchor length and depend on the impact velocity, anchor mass and shear strength of the soil. As with other plate anchors, the anchor needs to key before maximum capacity can be mobilised. Both the centrifuge and field experiments show that this keying and pullout behaviour is typical of other vertically installed plate anchors, where the main issue is the loss in embedment during keying. Both the experimental and numerical studies showed that the capacity of the DEPLA is much higher than that of other dynamically installed anchors with capacities up to 40 times the dry weight of the plate and plate bearing capacity factors of about 15.

Implementation of Circular Wave Measurements and Multiple Drilling Parameter Analysis in Rock Anisotropy Evaluation

2017 ◽  
Author(s):  
Abdelsalam N. Abugharara ◽  
Charles A. Hurich ◽  
John Molgaard ◽  
Stephen D. Butt
Keyword(s):  
Parameter Analysis ◽  
Laboratory Work ◽  
Depth Of Cut ◽  
Fine Aggregate ◽  
Laboratory Procedure ◽  
Rotary Drilling ◽  
Drilling Rig ◽  
Natural Rock ◽  
Drilling Parameters ◽  
Rock Anisotropy

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.

A Numerical Study on the Reactivity of Biogas/Reformed-Gas/Air and Methane/Reformed-Gas/Air Mixtures at Gas Turbine Relevant Conditions

2016 ◽  
Author(s):  
Pablo Diaz Gomez Maqueo ◽  
Philippe Versailles ◽  
Gilles Bourque ◽  
Jeffrey M. Bergthorson
Keyword(s):  
Gas Turbine ◽  
Laminar Flame ◽  
Numerical Study ◽  
Flame Temperature ◽  
Flame Speed ◽  
Flame Stability ◽  
Laminar Flame Speed ◽  
Fuel Reforming ◽  
Numerical Work ◽  
Chemical Effects

This study investigates the increase in methane and biogas flame reactivity enabled by the addition of syngas produced through fuel reforming. To isolate thermodynamic and chemical effects on the reactivity of the mixture, the burner simulations are performed with a constant adiabatic flame temperature of 1800 K. Compositions and temperatures are calculated with the chemical equilibrium solver of CANTERA® and the reactivity of the mixture is quantified using the adiabatic, freely-propagating premixed flame, and perfectly-stirred reactors of the CHEMKIN-Pro® software package. The results show that the produced syngas has a content of up to 30 % H2 with a temperature up to 950 K. When added to the fuel, it increases the laminar flame speed while maintaining a burning temperature of 1800 K. Even when cooled to 300 K, the laminar flame speed increases up to 30 % from the baseline of pure biogas. Hence, a system can be developed that controls and improves biogas flame stability under low reactivity conditions by varying the fraction of added syngas to the mixture. This motivates future experimental work on reforming technologies coupled with gas turbine exhausts to validate this numerical work.

Evaluation of Belleville Springs and Damping Through Static Cyclic Loading “Hysteresis” for pVARD Optimization: Part-I

2021 ◽  
Author(s):  
Abdelsalam Abugharara ◽  
Stephen Butt
Keyword(s):  
Data Analysis ◽  
Cyclic Loading ◽  
Dynamic Compression ◽  
Range Data ◽  
Compression Tests ◽  
Rotary Drilling ◽  
Static Compression ◽  
Drilling Performance ◽  
Wide Range ◽  
Compression Hysteresis

Abstract One unconventional application that researchers have been investigating for enhancing drilling performance, has been implemented through improving and stabilizing the most effective downhole drilling parameters including (i) increasing downhole dynamic weight on bit (DDWOB), (ii) stabilizing revolution per minutes (rpm), (iii) minimizing destructive downhole vibrations, among many others. As one portion of a three-part-research that consists of a comprehensive data analysis and evaluation of a static compression hysteresis, dynamic compression hysteresis, and corresponding drilling tests, this research investigates through static cyclic loading “Hysteresis” of individual and combined springs and damping the functionality of the passive Vibration Assisted Rotary Drilling (pVARD) tool that could be utilized towards enhancing the drilling performance. Tests are conducted on the two main pVARD tool sections that include (i) Belleville springs, which represent the elasticity portion and (ii) the damping section, which represents the viscous portion. Firstly, tests were conducted through static cyclic loading “Hysteresis” of (i) a mono elastic, (ii) a mono viscus, and (iii) dual elastic-viscus cyclic loading scenarios for the purpose of further examining pVARD functionality. For performing static compression tests, a calibrated geomechanics loading frame was utilized, and various spring stacking of different durometer damping were tested to seek a wide-range data and to provide a multi-angle analysis. Results involved analyzing loading and displacement relationships of individual and combined springs and damping are presented with detailed report of data analysis, discussion, and conclusions.

The effect of V-shape protruded and dimple textured on the load-carrying capacity and coefficient of friction of hydrodynamic journal bearing: A comparative numerical study

2020 ◽  
pp. 135065012093500
Author(s):  
Sanjay Sharma ◽  
Aniket Sharma ◽  
Gourav Jamwal ◽  
Rajeev Kumar Awasthi
Keyword(s):  
Coefficient Of Friction ◽  
Carrying Capacity ◽  
Performance Enhancement ◽  
Numerical Study ◽  
Geometrical Parameters ◽  
Load Carrying Capacity ◽  
Enhancement Ratio ◽  
Load Carrying ◽  
The Coefficient Of Friction ◽  
Computing Performance

The present comparative numerical study is between V-shape protruded, dimple textured, and untextured bearing. The performance parameters in terms of the load-carrying capacity and coefficient of friction are computed by solving governing Reynold’s equation of the lubricant fluid flow. The governing equation is solved by the finite element method by assuming that the fluid is Newtonian and isoviscous in nature. The effect of eccentricity ratios, texture distribution, texture heights, and texture depths are considered for the analysis in both textured bearings. From simulated results, the load-carrying capacity and coefficient of friction is found to be maximum for protruded textured bearing in full textured region and first half-textured region respectively as compared to untextured bearings. Finally, optimal operating and geometrical parameters of textured bearing is obtained by computing performance enhancement ratio, which is the ratio of the load-carrying capacity to the coefficient of friction. The maximum value of the performance enhancement ratio is found for protruded and dimple textured bearing in full texturing and second half-region corresponding to the eccentricity ratio of 0.8 and 0.6 respectively at texture height and depth of 0.4.

Thermal performance enhancement in a wedge duct with in-line pin fins combined with vortex generators

2019 ◽  
Vol 29 (8) ◽  
pp. 2545-2565
Author(s):  
Safeer Hussain ◽  
Jian Liu ◽  
Lei Wang ◽  
Bengt Ake Sunden
Keyword(s):  
Heat Transfer ◽  
Boundary Layer ◽  
Thermal Performance ◽  
Performance Enhancement ◽  
Numerical Study ◽  
Vortex Generators ◽  
Content Type ◽  
Pin Fin ◽  
Pin Fins ◽  
Cooling Enhancement

Purpose The purpose of this paper is to enhance the heat transfer and thermal performance in the trailing edge region of the vane with vortex generators (VGs). Design/methodology/approach This numerical study presents the enhancement of thermal performance in the trailing part of a gas turbine blade. In the trailing part, generally, pin fins are used either in staggered or in-line arrangements to enhance the heat transfer. In this study, based on the idea from heat exchangers, pin fins are combined with VGs. A pair of VGs is embedded in the boundary layer upstream of each pin fin in the first row of the pin fin array having an in-line configuration. The effects of the VG angle relative to the streamwise direction and streamwise distance between the pin fin and VGs are investigated at various Reynolds numbers. Findings The results indicated that the endwall heat transfer is enhanced with the addition of VGs and the heat transfer from the surfaces of the pin fins. The level of heat transfer enhancement compared to the case without VGs is more significant at high Reynolds number. The surfaces of the VGs also show a significant amount of heat transfer. Study of the angle of the attack suggested that a high angle of attack is more appropriate for pin fin cooling enhancement whereas an intermediate gap between the VGs and pin fins shows considerable improvement of thermal performance compared to the small and large gaps. The phenomenon of heat transfer augmentation with the VGs is demonstrated by the flow field. It shows that the enhancement of heat transfer is governed by the mixing of the flow as a result of the interaction of vortices generated by the VGs and pin fins. Originality/value VGs are used to disturb the thermal boundary layer. It shows that heat transfer is augmented as a result of the interaction of vortices associated with VGs and pin fins.

scholarly journals Numerical Study of Damage to Rock Surrounding an Underground Coal Roadway Excavation

2020 ◽  
Vol 2020 ◽  
pp. 1-16 ◽  
Author(s):  
Jiangbo Wei ◽  
Shuangming Wang ◽  
Zhou Zhao ◽  
Delu Li ◽  
Lipeng Guo
Keyword(s):  
Field Survey ◽  
Numerical Study ◽  
Coal Mines ◽  
Circumferential Stress ◽  
Distribution Patterns ◽  
Particle Flow ◽  
Particle Flow Code ◽  
Stress Release ◽  
Coal Roadway ◽  
Shallow Coal Seam

In coal mines, underground roadways are required to transport coal and personnel. Such tunnels can become unstable and hazardous. This study simulates deformation and damage in the rock surrounding a shallow coal seam roadway using particle flow code. A numerical model of particle flow in the surrounding rock was constructed based on field survey and drilling data. Microcharacteristic indices, including stress, displacement, and microcrack fields, were used to study deformation and damage characteristics and mechanisms in the surrounding rocks. The results show that the stress within the rock changed gradually from a vertical stress to a circumferential stress pattern. Stress release led to self-stabilizing diamond-shaped and X-shaped tensile stress distribution patterns after the excavation of the roadway. Cracking increased and eventually formed cut-through cracks as the concentrated stress transferred to greater depths at the sides, forming shear and triangular-shaped failure regions. Overall, the roof and floor were relatively stable, whereas the sidewalls gradually failed. These results provide a reference for the control of rock surrounding roadways in coal mines.

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