Stick-Slip Vibration of Drill Strings

1991 ◽  
Vol 113 (1) ◽  
pp. 38-43 ◽  
Author(s):  
Yao-Qun Lin ◽  
Yu-Hwa Wang
Keyword(s):  
Field Data ◽  
Phase Plane ◽  
Oil And Gas ◽  
Physical Phenomenon ◽  
Torsional Oscillation ◽  
Drill String ◽  
Stick Slip ◽  
Gas Well ◽  
Rotary Speed ◽  
Percent Accuracy

The stick-slip vibration is introduced as a new mechanism to explain the large amplitude torsional oscillation of the drill strings in oil and gas well drillings. A record of field data is identified and simulated according to the new mechanism. The analytical results derived from the numerical simulation agree with the field data with 95.6 percent accuracy. The physical phenomenon of the stick-slip vibration of drill string is explained by initiating a phase trace in the phase plane. The beating phenomenon in drilling is interpreted in terms of stick-slip vibration. The effects of viscous damping, rotary speed and natural frequency on the stick-slip vibration are discussed.

A Novel Backstepping Approach for the Attenuation of Torsional Oscillations in Drill Strings

2016 ◽  
Vol 248 ◽  
pp. 85-92 ◽  
Author(s):  
Farooq Kifayat Ullah ◽  
Franklyn Duarte ◽  
Christian Bohn
Keyword(s):  
Torsional Oscillation ◽  
Friction Model ◽  
Drill String ◽  
Cutting Process ◽  
Underactuated System ◽  
Drilling Process ◽  
Control Input ◽  
Nonlinear Phenomenon ◽  
Stick Slip ◽  
Torsional Oscillations

A common problem in the petroleum drilling process is the torsional oscillation generated by the friction present during the cutting process. Torsional oscillations in drill string are particularly difficult to control because the drill string is an underactuated system, it has a very small diameter to length ratio and it is driven at top end with the cutting process at the other end. These factors make the drill string prone to self-excited torsional vibrations caused by the stick-slip of the cutting bit. The system is modeled as a torsional pendulum with two degrees of freedom, where the upper inertia models the top drive and also part of the drilling pipes. The bottom inertia models the bottom hole assembly (BHA). The drill is considered to be a massless torsional spring-damper. The drill string is subjected to friction, which is formulated using a dry friction model. The friction model takes into account Coulomb friction, stiction and Stribeck effect. The latter friction component is the main nonlinear phenomenon that introduces negative damping at the bit; it leads to self-enforcing stick-slip torsional oscillations.In the approach of this work, for the attenuation of these self-excited oscillations a recursive backstepping control strategy is used and it is carried out in continuous time. The main contribution of this work, which is different from the backstepping approaches reported in the literature, is to use a nonlinear/artificial damping as virtual control input. The stability of the system has been proven in the sense of Lyapunov. The goal of the proposed algorithm is to deal the underactuation of the system and to provide a good response for different operating points. The effectiveness and robustness of the controller has been tested in simulations.

scholarly journals Drilling Vibration Modes and Penetration Rate Modeling using Artificial Neural Network and Multiple Linear Regression Analysis in Khoman Formation at the Egyptian Western Desert

2021 ◽  
Author(s):  
Sherif A. Ezz ◽  
Mohamed S. Farahat ◽  
Said Kamel ◽  
Ahmed Z. Nouh
Keyword(s):  
Neural Network ◽  
Regression Analysis ◽  
Penetration Rate ◽  
Drill String ◽  
Western Desert ◽  
Circulation Rate ◽  
Vibration Level ◽  
Stick Slip ◽  
Weight On Bit ◽  
Rotary Speed

Abstract Drill string vibrations are one of the most serious problems encountered while drilling as the bit and drill string interaction with formations under certain drilling conditions usually induces complex shocks and vibrations into the drill string components resulting in premature failure of the equipment and reduced drilling penetration rate. In severe cases where shocks and vibrations accumulated into drill string till exceeded its maximum yield or torsional strength, fatigue will occur and thereby increase the field development costs associated with replacing damaged components, fishing jobs, lost-in-hole situations, and sidetracks. Thus, real-time monitoring for downhole generated vibrations and accordingly adjusting drilling parameters including weight on bit, rotary speed, and circulation rate play a vital role in reducing the severity of these undesirable conditions. Vibration optimization must be done incorporation with the penetration rate, as a minimum economical penetration rate is required by the operator. In this study, three penetration rate and vibration level models were developed for axial, lateral, and stick-slip drilling modes using both MATLAB™ Software neural network and multiple regression analysis. It is found that the three models' results for vibration level and penetration rate; as compared with those recorded drilling data; showed an excellent match within an acceptable error of average correlation coefficient (R) over 0.95. The prediction of penetration rate and vibration level is thoroughly investigated in different axial, lateral, and stick-slip vibration drilling modes to be able to best select the optimum safe drilling zone. It is found that the axial vibration could be dampened by gradually increasing the weight on bit and increasing rotary speed while both the lateral and torsional vibrations are enhanced by increasing the rotary speed and decreasing the weight on bit.

scholarly journals Drillstring Failure: Analytical and Experimental Approach

2019 ◽  
Vol 300 ◽  
pp. 04004
Author(s):  
Edris Hassan ◽  
Jamil Abdo ◽  
Jan Kwak ◽  
Abdullah Al Shabibi
Keyword(s):  
Torsional Vibration ◽  
Oil And Gas ◽  
Drill Pipe ◽  
Oil And Gas Industry ◽  
Drill String ◽  
Design Parameters ◽  
Experimental Investigations ◽  
Torsional Vibrations ◽  
Stick Slip ◽  
The Impact

Drilling is one of the costliest activities in oil and gas industry due to the complexity of interactions with downhole rock formation. Under such conditions, the uncertainty of drillstring behaviour increase and hence it becomes difficult to predict the causes, occurrences, and types of failures. Lateral and torsional vibrations often cause failure of Bottom Hole Assembly (BHA), drillstring failure, drill bit and wall borehole damages. In this work, a model is presented to determine the impact of lateral and torsional vibrations on a drillstring during the drilling operation. The model aims to mimic real drillstring behaviour inside a wellbore with regards to its dynamic movements due to multiple real situations such as eccentricity of collars, drill pipe sections, and stick-slip phenomena occurring due to the interaction of the bit and the drillstring with the well formation. The work aims to develop a basis for determining critical operating speeds and design parameters to provide safe drilling procedures and reduce drill string fatigue failure. Lagrangian approach is used in this study to attain drillstring lateral and torsional vibration coupling equations. The nonlinear equations are solved numerically to obtain the response of the system. In this work, we also present a brief description of an in-house constructed experimental setup. The setup has the capability to imitate the downhole lateral and torsional vibration modes. Parameters from the experimental investigations are incorporated for validation of the mathematical models and for prediction of the drillstring fatigue life. Such investigations are essential for oil and gas industries as they provide solutions and recommendations about operational speed, lateral and torsional amplitudes measurements and corrections, and the conditions for avoiding occurrence of natural frequencies of the system.

scholarly journals Numerical Application of a Stick-Slip Control and Experimental Analysis using a Test Rig

2018 ◽  
Vol 148 ◽  
pp. 16009 ◽  
Author(s):  
Leonardo D. Pereira ◽  
Bruno Cayres ◽  
Hans I. Weber
Keyword(s):  
Deep Water ◽  
Torsional Vibration ◽  
Oil And Gas ◽  
Dynamical Behaviour ◽  
Drill String ◽  
Oil Field ◽  
Test Rig ◽  
Numerical Application ◽  
Stick Slip ◽  
Lateral Vibrations

Part of the process of exploration and development of an oil field consists of the drilling operations for oil and gas wells. Particularly for deep water and ultra deep water wells, the operation requires the control of a very flexible structure which is subjected to complex boundary conditions such as the nonlinear interactions between drill bit and rock formation and between the drill string and borehole wall. Concerning this complexity, the stick-slip phenomenon is a major component related to the torsional vibration and it can excite both axial and lateral vibrations. With these intentions, this paper has the main goal of confronting the torsional vibration problem over a test rig numerical model using a real-time conventional controller. The system contains two discs in which dry friction torques are applied. Therefore, the dynamical behaviour were analysed with and without controlling strategies.

scholarly journals Proportional-Derivative Control of Stick-Slip Oscillations in Drill-Strings

2018 ◽  
Vol 148 ◽  
pp. 16005 ◽  
Author(s):  
Wei Lin ◽  
Yang Liu
Keyword(s):  
Oil And Gas ◽  
Control Method ◽  
Drill String ◽  
Nonlinear Friction ◽  
Stick Slip ◽  
Gas Drilling ◽  
Drilling Parameters ◽  
Highly Nonlinear ◽  
Proportional Derivative Controller ◽  
Rock Bit

Stick-slip oscillation in drill-string is a universal phenomenon in oil and gas drilling. It could lead to the wear of drill bit, even cause catastrophic failure of drill-strings and measurement equipment. Therefore, it is crucial to study drilling parameters and develop appropriate control method to suppress such oscillation. This paper studies a discrete model of the drill-string system taking into account torsional degree-of-freedom, drill-string damping, and highly nonlinear friction of rock-bit interaction. In order to suppress the stick-slip oscillation, a new proportional-derivative controller, which can maintain drill bit’s rotation at a constant speed, is developed. Numerical results are given to demonstrate its efficacy and robustness.

Analysis of Friction-Induced Limit Cycling in an Experimental Drill-String System

2004 ◽  
Vol 126 (4) ◽  
pp. 709-720 ◽  
Author(s):  
N. Mihajlovic´ ◽  
A. A. van Veggel ◽  
N. van de Wouw ◽  
H. Nijmeijer
Keyword(s):  
Steady State ◽  
Oil And Gas ◽  
Static Friction ◽  
Friction Model ◽  
Drill String ◽  
Torsional Vibrations ◽  
State Behavior ◽  
Rotary Drilling ◽  
Stick Slip ◽  
Predictive Quality

In this paper, we aim for an improved understanding of the causes for torsional vibrations that appear in rotary drilling systems used for the exploration of oil and gas. For this purpose, an experimental drill-string setup is considered. In that system, torsional vibrations with and without stick-slip are observed in steady state. In order to obtain a predictive model, a discontinuous static friction model is proposed. The steady-state behavior of the drill-string system is analyzed both numerically and experimentally. A comparison of numerical and experimental bifurcation diagrams indicates the predictive quality of the model. Moreover, specific friction model characteristics can be linked to the existence of torsional vibrations with and without stick-slip.

Indirect Adaptive Robust Controller Design for Drilling Rotary Motion Control

2014 ◽  
Author(s):  
Fanping Bu ◽  
Jason Dykstra
Keyword(s):  
Oil And Gas ◽  
Controller Design ◽  
Drill String ◽  
Friction Torque ◽  
Robust Controller ◽  
Stick Slip ◽  
Oil And Gas Exploration ◽  
String Vibrations ◽  
Address System ◽  
Robust Controller Design

This paper presents the design and simulation of an indirect adaptive robust controller (IARC) for the rotatory drilling motion used in oil and gas exploration operations. To eliminate drill string vibrations, such as stick-slip, and achieve better control of drill bit rotating motion, an IARC controller was designed to compensate nonlinear friction torque directly and address system uncertainties during drilling. Simulation results are presented to illustrate the effectiveness of the designed IARC controller.

Mitigation of Stick-Slip Vibrations in Drilling Systems with Tuned Top Boundary Parameters

2020 ◽  
pp. 1-28
Author(s):  
Xianbo Liu ◽  
Zhao Zhang ◽  
Xie Zheng ◽  
Xinhua Long ◽  
Guang Meng
Keyword(s):  
Oil And Gas ◽  
Drill String ◽  
System Stability ◽  
Stick Slip ◽  
Alternative Approach ◽  
String Structure ◽  
Drilling Operations ◽  
Negative Damping ◽  
The Stability ◽  
Drilling Rigs

Abstract Aiming at preventing stick-slip oscillations in drilling systems for oil and gas explorations, a reduced-order model is proposed to capture the nonlinear torsional dynamics of drilling operations. In this model, the drill-string structure is simplified as a single-DOF system suffering from dry frictions at the drill bit, while the electromechanical boundary generated by the top-drive system is modeled as another tunable DOF used for stick-slip suppression. To simplify and parameterize the problems, a normalized 2-DOF system with negative damping and tunable parameters is deduced via nondimensionalization and linearization. Based on this system, stability criteria are obtained analytically in the 5-dimensional parametric space. Stable regions as well as the optimized boundary parameters are found analytically. The results suggest that the system can be stabilized by an optimally tuned boundary when and only when the magnitude of the negative damping is no greater than 2. It also reveals that the stability deteriorates if the inertia on the top is huge and non-adjustable, which is the commonest scenario for commercial drilling rigs nowadays. Finally, applications of the tuned boundary in a typical drilling system for stick-slip mitigation are conducted and verified numerically. The results indicate that the control performance can be potentially enhanced by three to five times, via an additional virtual negative inertia generated by the top-drive motor. This research provides an alternative approach to fully optimize the top boundary for curing stick-slip vibrations in drilling systems.

Fatigue Analysis of the Drill String According to Multiaxial Stress

2011 ◽  
Vol 418-420 ◽  
pp. 993-996 ◽  
Author(s):  
Jian Bing Zhang ◽  
Xiang Hong Lv
Keyword(s):  
Oil And Gas ◽  
Stress Amplitude ◽  
Axial Stress ◽  
Assessment Method ◽  
Drill String ◽  
Oil Field ◽  
Gas Well ◽  
Cyclic Stresses ◽  
The Mean ◽  
Axial Fatigue

To find out the cause for fatigue failure of a drill string used in oil field drilling, and considering the actual working conditions, axial, radial and circumferential cyclic stresses borne by the drill string in borehole of oil and gas well, fatigue strength of drill string is analyzed based on multi-axial fatigue assessment method. Then the formula to calculate the mean stress of multi-axial load of the drill string is obtained, and the formula serves as a method to calculate multi-axial fatigue life of the drill string, which has been verified through field data. It is realized that multi-axial stress has significant influence on drill string fatigue. When on drill string fatigue, Soderberg equation shall be employed to calculate the stress amplitude of drill string fatigue.

Investigation of the Influence of Screw Connections in Drill-Strings on the Propagation of Torsional Waves With Respect to Advanced Stick-Slip Controllers

2014 ◽  
Author(s):  
Edwin Kreuzer ◽  
Ludwig Krumm ◽  
Marc-André Pick
Keyword(s):  
Numerical Simulations ◽  
Oil And Gas ◽  
Control Method ◽  
Oil And Gas Industry ◽  
Drill String ◽  
Apparent Difference ◽  
Geothermal Resources ◽  
Stick Slip ◽  
Gas Industry ◽  
Drilling Rig

Drill strings are used in the oil and gas industry to search for oil, gas, and geothermal resources and form extremely slender structures which makes them very sensitive to torsional and other vibrations. In order to immensely reduce torsional vibrations along the whole string, a wave based control method was developed at our institute. Numerical simulations and tests at an experimental setup showed very good results, but the implementation in a real drilling rig has not yet been taken place. One apparent difference in a real drill string will be the assembly of many rather short drill pipes, which is unregarded in conventional models and our small test rig. This might lead to improper behavior of our wave based control mechanism and shall be investigated is this paper. We present a model that accounts for a discontinuously built drill string and show the consequences for our advanced control method via numerical simulations.

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