scholarly journals Numerical and Experimental Study on Belleville Springs as Vibrational Element of Passive Vibration Assisted Rotary Drilling (pVARD) Tool for Drilling Performance Applications

2020 ◽  
Author(s):  
Md. Shaheen Shah ◽  
Dipesh Maharjan ◽  
Abdelsalam Abugharara ◽  
Syed Imtiaz ◽  
Stephen Butt
2021 ◽  
Author(s):  
Abdelsalam Abugharara ◽  
Stephen Butt

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.


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.


Author(s):  
Omid Aminfar ◽  
Amir Khajepour

Reducing vibrations in well drilling has a significant effect on improving the overall performance of the drilling process. Vibrations may affect the drilling process in different ways, i.e., reducing durability of the drillstring’s elements, reducing the rate of penetration, and deviating the drilling direction. In rotary drilling, which is used to open mine and oil wells, torsional vibration of the drillstring is an important component of the overall system’s vibration that has received less attention in the literature. In this paper, we propose a finite element model for a sample blasthole drillstring used to open mine wells to investigate its torsional vibrations. Boundary conditions and elements’ specifications are applied to this model. In the model, the interaction between the insert and the rock is represented by a set of repetitive impulses according to the insert pattern. The steady-state response of the system to the repetitive impulses is found and natural frequencies, kinetic energy, and potential energy of the drillstring are calculated. The root mean square (RMS) of the total energy can be used as the measure for reducing the torsional vibration of the system. Finally, an optimum combination of inserts on the cone’s rows was found based on minimizing the total vibratory energy of the drillstring. The optimum design can reduce the torsional vibrations of the drillstring and improve the drilling performance.


2021 ◽  
Author(s):  
Kingsley Amadi ◽  
Ibiye Iyalla ◽  
Radhakrishna Prabhu

Abstract This paper presents the development of predictive optimization models for autonomous rotary drilling systems where emphasis is placed on the shift from human (manual) operation as the driving force for drill rate performance to Quantitative Real-time Prediction (QRP) using machine learning. The methodology employed in this work uses real-time offset drilling data with machine learning models to accurately predict Rate of Penetration (ROP) and determine optimum operating parameters for improved drilling performance. Two optimization models (physics-based and energy conservation) were tested using Artificial Neutral Network (ANN) algorithm. Results of analysis using the model performance assessment criteria; correlation coefficient (R2) and Root Mean Square Error (RMSE), show that drill rate is non-linear in nature and the machine learning model (ANN) using energy conservation is most accurate for predicting ROP due to its ability in establishing a functional feature vector based on learning from past events.


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

Abstract This work concentrates on the investigation of enhancing drilling performance through increasing drilling rate of penetration (ROP) by using a passive vibration assisted rotary drilling (pVARD) tool. It also involves analysis of how ROP was significantly increased when drilling using pVARD compared to drilling using conventional system “rigid” using coring and drilling in shale rocks. The apparatus used was a fully instrument laboratory scale rig and the bits were dual-cutter polycrystalline diamond compact (PDC) bit for drilling and diamond impregnated coring bit for coring. The flow rate was constant of (7 litter / min) using clean water at atmospheric pressure. In addition, for accuracy data recording, a data acquisition system (DAQ-Sys) using a LabVIEW software was utilized to record data at 1000HZ sampling rate. The output drilling parameters involved in the analysis included operational rpm, torque (TRQ), and ROP. All the output-drilling parameters were analyzed with relation to downhole dynamic weight on bit (DDWOB). The result of this work explained how pVARD can increase the DDWOB and improve ROP. The result also demonstrated generating a balanced and concentric increase in DDWOB and minimizing the wide-range fluctuation of DDWOB generated in rigid drilling, particularly at high DDWOB.


Author(s):  
Abourawi Alwaar ◽  
Abdelsalam N. Abugharara ◽  
Stephen D. Butt

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.


2020 ◽  
pp. 1-12
Author(s):  
Jeronimo de Moura Junior ◽  
Jianming Yang ◽  
Stephen D. Butt

Abstract The drilling process is one of the most important and expensive aspects of the oil and gas industry. In consequence, an accurate prediction of the rate of penetration (ROP) is crucial to the optimization of drilling performance and thus, contributes directly to reducing drilling costs. Knowledge of drilling performance is a vital tool in the development of a consistent drilling plan and allows industry players to anticipate issues that may occur during a drilling operation. Several approaches to predict the drilling performance have been tried with varying degrees of success, complexity and accuracy. In this paper, a review of the history of drilling performance prediction is conducted with emphasis on rotary drilling with fixed cutter drill bits. The approaches are grouped into two categories: physics-based and data-driven models. The paper's main objective is to present an accurate model to predict the drilling performance of fixed cutter drill bits including the founder point location. This model was based on a physics-based approach due to its low complexity and good accuracy. This development is based on a quantitative analysis of drilling performance data produced by laboratory experiments. Additionally, the validation and applicability tests for the proposed model are discussed based on DOTs and field trials in several different drilling scenarios. The proposed model presented high accuracy to predict the fixed cutter drill bit drilling performance in the twenty-seven different drilling scenarios which were analyzed in this paper.


2021 ◽  
Vol 9 (1) ◽  
Author(s):  
Jan-Erik Rosberg ◽  
Mikael Erlström

AbstractThe 3.1- and 3.7-km-deep FFC-1 and DGE-1 geothermal explorations wells drilled into the Precambrian crystalline basement on the southern margin of the Fennoscandian Shield are evaluated regarding experiences from drilling, geological conditions, and thermal properties. Both wells penetrate an approximately 2-km-thick succession of sedimentary strata before entering the crystalline basement, dominated by orthogneiss, metabasite and amphibolite of the (1.1–0.9 Ga) Eastern Interior Sveconorwegian Province. The upper c. 400 m of the basement is in FFC-1 severely fractured and water-bearing which disqualified the use of percussion air drilling and conventional rotary drilling was, therefore, performed for the rest of the borehole. The evaluation of the rotary drillings in FFC-1 and DGE-1 showed that the average bit life was very similar, 62 m and 68 m, respectively. Similarly, the average ROP varied between 2 and 4 m/h without any preferences regarding bit-type (PDC or TCI) or geology. A bottomhole temperature of 84.1 °C was measured in FFC-1 borehole with gradients varying between 17.4 and 23.5 °C/km for the main part of the borehole. The calculated heat flow varies between 51 and 66 mW/m2 and the average heat production is 3.0 µW/m3. The basement in FFC-1 is, overall, depleted in uranium and thorium in comparison to DGE-1 where the heat productivity is overall higher with an average of 5.8 µW/m3. The spatial distribution of fractures was successfully mapped using borehole imaging logs in FFC-1 and shows a dominance of N–S oriented open fractures, a fracture frequency varying between 0.85 and 2.49 frac/m and a fracture volumetric density between 1.68 and 3.39 m2/m3. The evaluation of the two boreholes provides insight and new empirical data on the thermal properties and fracturing of the concealed crystalline basement in the Fennoscandian Shield Border Zone that, previously, had only been assessed by assumptions and modelling. The outcome of the drilling operation has also provided insight regarding the drilling performance in the basement and statistical data on various drill bits used. The knowledge gained is important in feasibility studies of deep geothermal projects in the crystalline basement in south Sweden.


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