scholarly journals Comparative analysis of roller drill bit performance

Author(s):  
A. O. Shigin ◽  
◽  
D. A. Boreyko ◽  
N. D. Tskhadaya ◽  
D. Yu. Serikov ◽  
...  

Currently, roller bits are widely used in rock drilling, which are devices with rotating rollers armed with teeth. There are various approaches in assessing the effectiveness of rock destruction by a roller drilling tool, which can be conditionally divided into structural and technological ones. In addition, all the efficiency factors of the roller bit are related to the correspondence of its characteristics and the drilling process to the properties of the rock it destroys. The article analyzes the operating conditions of the roller bit during drilling of rocks of various hardness. On the example of operation of a two-screw drill bit, the process of power interaction of the toothed weapon with rock is considered depending on various factors, such as the shape and pitch of the teeth, angle of inclination, sharpness of the tooth and others. It is shown that kinematic characteristics of interaction of toothed armament with drilled rock have a significant influence on efficiency of process of face destruction. Keywords: drill bit; drilling tool; destruction; drilling; roller cutter; rock.

2021 ◽  
Vol 18 (2) ◽  
pp. 160-167
Author(s):  
I. G. Martiuchenko ◽  
M. I. Zenin

Introduction. Drilling of frozen and permafrost soils is one of the complex and energy-intensive processes of earthworks. Drilling tools used on frozen soils implement the process of drilling the soil by deformation of cutting or crushing action. Current drilling tools are not efficient enough to use because they implement energy-intensive drilling processes and are not always suitable for various types of soils. A screw drill is considered, which implements the process of soil destruction by shear and shear deformation, which is less energy intensive.Materials and methods. On the basis of theoretical studies of the interaction of 3 types of drilling tools with frozen soil, a comparative analysis was carried out to determine the efficiency of a screw drill use. The technical and economic indicators of the drilling process were compared. A method for determining the efficiency of the use a screw drill based on the analysis of special target functions is presented.Results. The results of a comparative analysis of drilling tools have been obtained. Depending on the nature of soil deformation, the effectiveness of one drilling tool over another is determined. As a result of a comparative analysis of the drilling speed and the energy intensity of the drilling process, the efficiency of the screw drill was established.Discussions and conclusion. In the course of the comparative analysis, the efficiency of the screw drill was determied, which implements shear deformation and soil separation, justifying the feasibility of further research.


Author(s):  
В. М. Мойсишин ◽  
M. V. Lyskanych ◽  
R. A. Zhovniruk ◽  
Ye. P. Majkovych

The purpose of the proposed article is to establish the causes of oscillations of drilling tool and the basic laws of the distribution of the total energy of the process of changing the axial dynamic force over frequencies of spectrum. Variable factors during experiments on the classical plan were the rigidity of drilling tool and the hardness of the rock. According to the results of research, the main power of the process of change of axial dynamic force during drilling of three roller cone bits is in the frequency range 0-32 Hz in which three harmonic frequency components are allocated which correspond to the theoretical values of low-frequency and gear oscillations of the chisel and proper oscillations of the bit. The experimental values of frequencies of harmonic components of energy and normalized spectrum as well as the magnitude of the dispersion of the axial dynamic force and its normalized values at these frequencies are presented. It has been found that with decreasing rigidity of the drilling tool maximum energy of axial dynamic force moves from the low-frequency oscillation region to the tooth oscillation area, intensifying the process of rock destruction and, at the same time, protecting the tool from the harmful effects of the vibrations of the bit. Reducing the rigidity of the drilling tool protects the bit from the harmful effects of the vibrations generated by the stand. The energy reductions in these fluctuations range from 47 to 77%.


Author(s):  
Jialin Tian ◽  
Xuehua Hu ◽  
Liming Dai ◽  
Lin Yang ◽  
Yi Yang ◽  
...  

This paper presents a new drilling tool with multidirectional and controllable vibrations for enhancing the drilling rate of penetration and reducing the wellbore friction in complex well structure. Based on the structure design, the working mechanism is analyzed in downhole conditions. Then, combined with the impact theory and the drilling process, the theoretical models including the various impact forces are established. Also, to study the downhole performance, the bottom hole assembly dynamics characteristics in new condition are discussed. Moreover, to study the influence of key parameters on the impact force, the parabolic effect of the tool and the rebound of the drill string were considered, and the kinematics and mechanical properties of the new tool under working conditions were calculated. For the importance of the roller as a vibration generator, the displacement trajectory of the roller under different rotating speed and weight on bit was compared and analyzed. The reliable and accuracy of the theoretical model were verified by comparing the calculation results and experimental test results. The results show that the new design can produce a continuous and stable periodic impact. By adjusting the design parameter matching to the working condition, the bottom hole assembly with the new tool can improve the rate of penetration and reduce the wellbore friction or drilling stick-slip with benign vibration. The analysis model can also be used for a similar method or design just by changing the relative parameters. The research and results can provide references for enhancing drilling efficiency and safe production.


Author(s):  
Nitin P. Sherje ◽  
Sameer A. Agrawal ◽  
Ashish M. Umbarkar ◽  
Prashant P. Kharche ◽  
Dharmesh Dhabliya

Author(s):  
Jialin Tian ◽  
Jie Wang ◽  
Siqi Zhou ◽  
Yinglin Yang ◽  
Liming Dai

Excessive stick–slip vibration of drill strings can cause inefficiency and unsafety of drilling operations. To suppress the stick–slip vibration that occurred during the downhole drilling process, a drill string torsional vibration system considering the torsional vibration tool has been proposed on the basis of the 4-degree of freedom lumped-parameter model. In the design of the model, the tool is approximated by a simple torsional pendulum that brings impact torque to the drill bit. Furthermore, two sliding mode controllers, U1 and U2, are used to suppress stick–slip vibrations while enabling the drill bit to track the desired angular velocity. Aiming at parameter uncertainty and system instability in the drilling operations, a parameter adaptation law is added to the sliding mode controller U2. Finally, the suppression effects of stick–slip and robustness of parametric uncertainty about the two proposed controllers are demonstrated and compared by simulation and field test results. This paper provides a reference for the suppression of stick–slip vibration and the further study of the complex dynamics of the drill string.


2021 ◽  
Author(s):  
Tianhua Zhang ◽  
Shiduo Yang ◽  
Chandramani Shrivastava ◽  
Adrian A ◽  
Nadege Bize-Forest

Abstract With the advancement of LWD (Logging While Drilling) hardware and acquisition, the imaging technology becomes not only an indispensable part of the drilling tool string, but also the image resolution increases to map layers and heterogeneity features down to less than 5mm scale. This shortens the geological interpretation turn-around time from wireline logging time (hours to days after drilling) to semi-real time (drilling time or hours after drilling). At the same time, drilling motion is complex. The depth tracking is on the surface referenced to the surface block movement. The imaging sensor located downhole can be thousands of feet away from the surface. Mechanical torque and drag, wellbore friction, wellbore temperature and weight on bit can make the downhole sensor movement motion not synchronized with surface pipe depth. This will cause time- depth conversion step generate image artifacts that either stop real-time interpretation of geological features or mis-interpret features on high resolution images. In this paper, we present several LWD images featuring distortion mechanism during the drilling process using synthetic data. We investigated how heave, depth reset and downhole sensor stick/slip caused image distortions. We provide solutions based on downhole sensor pseudo velocity computation to minimize the image distortion. The best practice in using Savitsky-Golay filter are presented in the discussion sections. Finally, some high-resolution LWD images distorted with drilling-related artifacts and processed ones are shown to demonstrate the importance of image post-processing. With the proper processed images, we can minimize interpretation risks and make drilling decisions with more confidence.


2021 ◽  
Author(s):  
Sion Llywelyn Roberts ◽  
Michael James Bailey ◽  
Afshin Babaie Aghdam ◽  
Ahmed Suleiman ◽  
Ahmed Fathy

Abstract As oil and gas wells become deeper, drilling longer intervals is becoming a major milestone for drill bit companies, as the process comes with a variety of challenges affecting the durability of drill bits. Among the major challenges are thermal and impact damage in polycrystalline diamond compact (PDC) cutters, which can significantly affect the performance and longevity of a drill bit. While cutter technology development remains an important arena to address said challenges, there exists a need to also address these through the design process. This paper presents the development and deployment of a new drill bit analysis method that addresses thermal damage by optimizing the design, which has been field validated across the globe. The analysis involves estimating the thermal input load and the available cooling rate for every cutter on a drill bit during drilling conditions. The data is then used to optimize and apply changes to the design. The analysis considers all the critical and relevant operational parameters to calculate these indices. The outcome of the so-called thermal index analysis enables the design team to make informed decisions to improve the design of the drill bit and to minimize the extent of thermal damage in cutters. The improvements made in the design include changes in cutting structure to affect cutting forces and, eventually, the thermal input load during the drilling process. This stage in practice can bring down the temperature of the cutting edge by 20%, as calculated analytically. Another major change that can affect the results is hydraulic design of the bit, which includes the location of the nozzles as well as their orientation and size. In test cases, the cooling rate improved by 50% while keeping the same flow rate though the bit. Several field trials have validated the correlation of thermal index analysis to drill bit dulls. This analysis is now in the field evaluation and testing phase, where it is being used during the design process to improve bits with thermal damage. The field-testing phase has been primarily conducted in thermally challenging applications across the Middle East, North Africa region, and in West Texas.


2017 ◽  
Vol 62 (3) ◽  
pp. 1803-1812 ◽  
Author(s):  
K. Shunmugesh ◽  
K. Panneerselvam

AbstractCarbon Fiber Reinforced Polymer (CFRP) is the most preferred composite material due to its high strength, high modulus, corrosion resistance and rigidity and which has wide applications in aerospace engineering, automobile sector, sports instrumentation, light trucks, airframes. This paper is an attempt to carry out drilling experiments as per Taguchi’s L27(313) orthogonal array on CFRP under dry condition with three different drill bit type (HSS, TiAlN and TiN). In this research work Response Surface Analysis (RSA) is used to correlate the effect of process parameters (cutting speed and feed rate) on thrust force, torque, vibration and surface roughness. This paper also focuses on determining the optimum combination of input process parameter and the drill bit type that produces quality holes in CFRP composite laminate using Multi-objective Taguchi technique and TOPSIS. The percentage of contribution, influence of process parameters and adequacy of the second order regression model is carried out by analysis of variance (ANOVA). The results of experimental investigation demonstrates that feed rate is the pre-dominate factor which affects the response variables.


2016 ◽  
Vol 712 ◽  
pp. 55-59
Author(s):  
Vladislav M. Vazhov ◽  
Sergey Y. Datskevitch ◽  
Mikhail Y. Zhurkov ◽  
Vasily M. Muratov ◽  
Arild Rødland

The article covers the research of the electric strength and fracture of rocks that are undergone multiple breakdowns generated by electric discharge rock fracture and drilling technologies. The research outcomes allow proposing an experimental technology able to determine operating high voltage pulse values in the electric discharge drilling process where one should take into account such factors as the rock re-crushing and the drill bit shift cyclicity.


Sign in / Sign up

Export Citation Format

Share Document