hole making
Recently Published Documents


TOTAL DOCUMENTS

153
(FIVE YEARS 52)

H-INDEX

18
(FIVE YEARS 3)

2021 ◽  
Vol 15 (4) ◽  
pp. 91-98
Author(s):  
Yuriy Katanov ◽  
Yuriy Vaganov ◽  
Matvey Cheymetov

Purpose is the development of mathematical models to evaluate deformation of parameters of the rock mass-well geological and engineering system within the anisotropic media. Methods. Both mathematical and neural modeling of a stress state of the rock mass-well system under conditions of geological uncertainty has been applied for the studies. From the viewpoint of mathematical modeling, analysis of probability of factors, complicating drilling, should involve a number of assumptions for strength and deformation characteristics of rock mass layers corresponding to particular hole-making conditions. Findings. A mathematical model of horizontal wellbore and geological layers, occurring along the structure under the conditions of permanent comprehensive stresses, has been developed. An analytical and graphical form has been applied to implement one of the basic aspects of aggregation principles of strength changes in each particular lithological layer for identification of an ideal value of horizontal/inclined wellbore length relative to the rock mass depths scheduled by mining. Regularities of changes in deformation and spatial well stability within the complex reservoirs depending upon various process duties have been determined. A neural simulation-based model has been proposed to analyze deformation of rock mass layers having different strength characteristics. Originality. Interaction between geomechanical characteristics of rock mass as well as deformation and spatial stability of well design has been evaluated both qualitatively and quantitatively. Practical implications. An opportunity has been presented to forecast deformation of well walls taking into consideration different strength as well as structural and geological rock mass characteristics on the basis of neural simulation. The represented approach has been included on the register of the best scientific-based practices according to “Methods to recover low-pressure gas of Cenomanian producing complex” Project.


Author(s):  
Omid Paysarvi ◽  
Mohammad Mahdi Abootorabi ◽  
Mohammad Mahdi Jalili

Helical milling is one of the novel hole-making methods to create a hole with high accuracy and quality. In this study, the helical milling process is dynamically modeled using a set of second-order differential equations. In this modeling, the tool is considered a cantilever beam with a degree of freedom in all three directions of x, y, and z. Experimental tests were conducted to investigate the validity of the obtained theoretical relations and the effects of different parameters such as material, diameter, and rotational speed of the cutting tool on the precision of the created hole. The error of the theoretical relations in predicting the hole diameter is 2.7%, indicating the high precision of the accomplished modeling. Theoretical relations show that the error of the chip removal path decreases by increasing each of the parameters, namely, tool stiffness, the rotational speed of the tool, tool diameter, and tangential feed per tooth. In contrast, the error of the chip removal path increases by increasing each of the parameters, namely, the speed of the tool in the helical path and axial feed per tooth. It has been shown that improving the cutting tool material in terms of strength or increasing the rotational speed of the tool and the cutting tool diameter causes a reduction in the diametrical error. It has been shown that the diametrical error rate is 0.9% with the change of the cutting tool from HSS-E to carbide, and it has reduced to 0.6% by increasing the rotational speed of the tool from 900 r/min to 2100 r/min.


Author(s):  
Samadhan Suresh Mule

Abstract: Friction drilling is a novel hole-making method that can be performed on thin-walled sheets. In recent years of study, the thrust force and torque under numerous process conditions were performed to demonstrate the benefits. In recent years of study, the thrust force and torque under various process conditions were performed to demonstrate the benefits. Our objective is to review the behavior of the material with the use of friction drilling by variation of thickness, Spindle speed, and feed rate. Our objective is to study the behavior of the material with the use of friction drilling by variation of thickness, Spindle speed, and feed rate. The friction between a rapid rotating conical tool and a sheet metal workpiece generates heat to soften and displace the metal to form a whole. Friction drilling is a non-traditional hole-making process in which a conical rotating tool is applied to penetrate the workpiece and make the outlet in a single step, without generating chips. the process relies on the heat generated thanks to the resistance force between tool and workpiece, to soften, penetrate and deform the work material into a bushing shape. Generally, friction drilling is applied to thin-walled materials owing to increasing connection length and clamping strength. The generated resistance heat cause softening piece of work material, increase its ductility, and providing it to flow, that extruded onto both the front and back sides of the holes. Keywords: Friction Drilling, Conical Tool, Material Displace, Temperature, Hardness & Thickness.


2021 ◽  
Author(s):  
Linghao Kong ◽  
Dong Gao ◽  
Yong Lu ◽  
Pengfei Zhang

Abstract As the most promising CFRP hole making method, orbital drilling is widely concerned. This paper aims to understand the influence of the cutting parameters, tool diameters and ratio between milling and drilling (Rm&d) on thrust force, cutting temperature, tool wear and machining quality in CFRP orbital drilling. The effects of cutting parameters on thrust force and cutting temperature were studied by orthogonal experiments, and experiments were performed to investigate the variations of tool diameters, ratio between drilling and milling on thrust force, cutting temperature, tool wear and machining quality. The experimental results show that the tangential feed rate has no apparent effects on thrust force, but it appreciably impacts on the cutting temperature. The selection of tool diameter and the Rm&d has specific influence on tool wear, machining quality and cutting temperature. The result is helpful for selecting cutting parameters and tool diameters for high quality holes machining in CFRP orbital drilling.


2021 ◽  
Author(s):  
Rahmat Ashari ◽  
Owen Sorensen ◽  
Pradeepkumar Ashok ◽  
Eric van Oort ◽  
Matthew Isbell ◽  
...  

Abstract Although numerous studies have investigated how shocks and vibrations contribute to bottomhole assembly (BHA) failures during hole-making, very few have explicitly focused on shock and vibrational behaviors during drillpipe connections. This study adopts a data-driven approach to explore various connection practices and their associated shocks and vibrations, aiming to propose optimum "connection recipes" that minimize negative drillstring impacts during connections. This study utilized data from surface sensors as well as downhole accelerometers and gyroscopes installed both at a downhole sub and the bit. In total, 520 connections from 5 lateral sections were studied. Several quality checks and corrections were performed to ensure synchronization between surface and downhole data. The analyses focused on two connection phases specifically: going off-bottom and going back to bottom. The presence of stick-slip events and high magnitudes of both maximum and root mean squared (RMS) radial accelerations were examined together with the associated surface drilling parameters. Various visualization approaches were performed to help demonstrate the vibration and shock behaviors resulting from different going off-bottom and going back to bottom practices. The analyses showed that restarting surface rotational speed at low values (≤ 40 RPM) risks inducing stick-slip events when going back to bottom. When the surface RPM was increased sufficiently, a notable reduction in RMS radial acceleration was observed. Maximum radial acceleration magnitude was highest before WOB application, which could be mitigated by immediate WOB re-application. Appreciable variation in the maximum radial acceleration was apparent when restarting at low (≤ 15 klbf) WOB values. When going off-bottom, drilling off should be accompanied by a reduction in the surface rotational speed to avoid a jump in the maximum radial acceleration values. This work provides suggestions on how to execute better connections. Since the impacts of shocks and vibrations during connections have previously been largely overlooked, this study fills a knowledge gap to help establish better practices and automation routines to improve the lifespan of the bit and downhole tools.


Sign in / Sign up

Export Citation Format

Share Document