ANALYSIS OF COUPLED DRILL-STRING VIBRATIONS USING A NONSMOOTH SYSTEM

2016 ◽  
Author(s):  
Luciano Moraes ◽  
Marcelo Savi
Keyword(s):  
Drill String ◽  
Nonsmooth System ◽  
String Vibrations

Drill String Vibrations Due to Intermittent Contact of Bit Teeth

1963 ◽  
Vol 85 (2) ◽  
pp. 187-194 ◽  
Author(s):  
P. R. Paslay ◽  
D. B. Bogy
Keyword(s):  
Experimental Data ◽  
Penetration Rate ◽  
Drill String ◽  
String Vibrations ◽  
Order Of Magnitude ◽  
Intermittent Contact ◽  
Maximum Penetration ◽  
Sufficient Magnitude ◽  
Force Excitation ◽  
Practical Measurement

An analysis of the longitudinal forces and the resulting longitudinal motions of an idealized drill string is presented. The only external force excitation considered occurs at the bit and is due to the intermittent contact of the teeth with the bottom of the hole. Attention has been restricted to the following two salient possibilities: 1 - Excitation at the bit may develop oscillating forces at the bit with amplitudes of the same order of magnitude as those of the bit load. 2 - Appreciable bit load variation may be detected by instruments which measure the motion of the drill string near its top. The first possibility is important if maximum penetration rate is to be achieved, and the second possibility is important in implementing practical measurement of the phenomenon. From the results of the specific example considered in this report, it is concluded that possibilities 1 and 2 may occur in sufficient magnitude to be influential, but experimental data on the actual bit motion and the damping will be required to evaluate the effect. The analysis is presented in such form that the influence of the various parts of the system can easily be evaluated.

The Study on Harmonic Vibration of Drill String in Horizontal Well

2010 ◽  
Vol 139-141 ◽  
pp. 2397-2400
Author(s):  
Chun Jie Han ◽  
Tie Yan
Keyword(s):  
Horizontal Well ◽  
Drill String ◽  
Harmonic Vibration ◽  
Well Drilling ◽  
Harmonic Vibrations ◽  
String Vibrations ◽  
Resonance Frequencies ◽  
Set Up ◽  
Drill Tool ◽  
Modal Vibration

During exploitation of horizontal well drilling engineering, the problem of drill string failure is very serious, there are many reasons, and drill string vibrations are main reasons. In this paper drill string of horizontal well is object being studied. The models about various vibrations are set up. The vibration rule of drill string is obtained under different situation; the axial and lateral frequency of drill string vibration in free state is studied. The analysis of modal vibration of drill string is the basis of the analysis of harmonic vibration of drill string. The harmonic vibrations rules of drill string of horizontal well are studied. All sorts of resonance frequencies are obtained practicability. This study can prove basic method for optimizing drill tool of horizontal well and reducing drill string failure.

Longitudinal and Angular Drill-String Vibrations With Damping

1968 ◽  
Vol 90 (4) ◽  
pp. 671-679 ◽  
Author(s):  
D. W. Dareing ◽  
B. J. Livesay
Keyword(s):  
Viscous Friction ◽  
Field Measurements ◽  
Computer Programs ◽  
Drill String ◽  
Recording Instrument ◽  
String Vibration ◽  
String Vibrations ◽  
Different Types ◽  
Drilling Operations ◽  
Computer Calculations

This paper discusses longitudinal and angular drill-string vibrations and supporting field measurements taken with a special downhole recording instrument. Computer programs based on the theory are used to calculate longitudinal and angular vibrations (caused by periodic bit motions) along the drill string; field measurements made during actual drilling operations are used to check computer calculations. The main difference between this and other theory on the same problem is the inclusion of friction, which acts along the length of a drill string and impedes longitudinal and angular vibrations. For the sake of simplicity, the effect of different types of friction, such as fluid, rubbing, and material, which act along the string, is approximated by the effect produced by viscous friction. This approximation is generally accepted and appears to give adequate results for the drill-string vibration problem.

scholarly journals A Review of the Evaluation, Control, and Application Technologies for Drill String Vibrations and Shocks in Oil and Gas Well

2016 ◽  
Vol 2016 ◽  
pp. 1-34 ◽  
Author(s):  
Guangjian Dong ◽  
Ping Chen
Keyword(s):  
Passive Control ◽  
Oil And Gas ◽  
Field Studies ◽  
Drill String ◽  
Vibration Measurement ◽  
Semiactive Control ◽  
Rate Of Penetration ◽  
Drilling Performance ◽  
String Vibrations ◽  
Control Technologies

Drill string vibrations and shocks (V&S) can limit the optimization of drilling performance, which is a key problem for trajectory optimizing, wellbore design, increasing drill tools life, rate of penetration, and intelligent drilling. The directional wells and other special trajectory drilling technologies are often used in deep water, deep well, hard rock, and brittle shale formations. In drilling these complex wells, the cost caused by V&S increases. According to past theories, indoor experiments, and field studies, the relations among ten kinds of V&S, which contain basic forms, response frequency, and amplitude, are summarized and discussed. Two evaluation methods are compared systematically, such as theoretical and measurement methods. Typical vibration measurement tools are investigated and discussed. The control technologies for drill string V&S are divided into passive control, active control, and semiactive control. Key methods for and critical equipment of three control types are compared. Based on the past development, a controlling program of drill string V&S is devised. Application technologies of the drill string V&S are discussed, such as improving the rate of penetration, controlling borehole trajectory, finding source of seismic while drilling, and reducing the friction of drill string. Related discussions and recommendations for evaluating, controlling, and applying the drill string V&S are made.

scholarly journals Adaptive Control of Drill String Vibrations

2019 ◽  
Vol 54 (9-10) ◽  
pp. 711-716 ◽  
Author(s):  
É. A. Petrovskii ◽  
K. A. Bashmur ◽  
I. S. Nashivanov
Keyword(s):  
Adaptive Control ◽  
Drill String ◽  
String Vibrations

Experimental Investigation of the Vibration Control of Nonrotating Periodic Drill Strings

2021 ◽  
Vol 143 (6) ◽  
Author(s):  
Sadok Sassi ◽  
Jamil Renno ◽  
Han Zhou ◽  
Amr Baz
Keyword(s):  
Oil And Gas ◽  
Axial Loading ◽  
Drill String ◽  
Drilling Process ◽  
Oil And Gas Fields ◽  
String Vibrations ◽  
Wide Range ◽  
Vibration Transmissibility ◽  
Drilling Operations ◽  
Gas Fields

Abstract During the drilling process in oil and gas fields, slender drill strings often experience a multitude of complex and simultaneous vibrational phenomena. Drill string vibrations hinder the drilling process and can cause premature wear and damage to the drilling equipment. Here, the suppression of drill string vibrations during drilling operations is experimentally investigated using a novel drill string design, based on the use of innovative periodic inserts that control the vibration transmissibility in different directions. These inserts are equipped with viscoelastic rings that act as sources of local resonances, surrounding piezoelectric actuators that generate internal axial loading when electrically excited. An experimental prototype that combined all these details was constructed and tested to demonstrate the periodic drill string's feasibility and effectiveness in minimizing undesirable vibrations. The obtained results indicate that the periodic inserts’ careful design can effectively enhance the drill strings’ dynamic behavior and conveniently regulate its bandgap characteristics. Both radial and axial vibrations were controlled, and the vibrations’ amplitude was reduced significantly over a wide range of frequencies. The proposed approach appears to present a viable means for designing intelligent drill strings with tunable bandgap characteristics.

On the Influence of the Equivalent Circulent Density Fluctuations on the Development of the Wellbore Natural Fracture

2021 ◽  
Author(s):  
Arnaud Regis Kamgue Lenwoue ◽  
Jingen Deng ◽  
Yongcun Feng ◽  
Naomie Beolle Songwe Selabi
Keyword(s):  
Finite Element ◽  
Drill String ◽  
Natural Fracture ◽  
Cyclic Loads ◽  
Fracture Width ◽  
Wellbore Instability ◽  
Fracture Length ◽  
String Vibration ◽  
String Vibrations ◽  
Drilling Operations

Abstract Wellbore instability is one of the most important causes of Non-Productive Time during drilling operations causing billions of dollars of losses every year. During the drilling stage, the Equivalent Circulent Density (ECD) is subjected to fluctuations caused by some factors such as the drill string vibrations cyclic loads. The fluctuating ECD applied on the fractured formation progressively modifies the initial parameters of the fractured formation such as its length and its width and this process finally results into wellbore instability. In this research, a poroelastic model based on a finite element method has been established to analyze the influence of the drill string vibration cyclic loads on the development of the wellbore natural fracture. The analysis was conducted with a two-dimensional plane strain model. A traction-separation law based on energy has been proposed for the Cohesive Zone Model. A nonlinear finite element software ABAQUS was utilized as the numerical simulator. The numerical results showed that the profiles of the fracture width as a function of time follow a sinusoidal behavior similar to the behavior of the drill string vibration cyclic loads profile. For different values of the Weight On Bit (WOB) and constant drill string Revolution Per Minute (RPM), an increase of the fracture width with the fracture length is observed in the near wellbore region. In the region far away the wellbore, the fracture width globally decreases with an increase of the fracture length for each fracture profile. the investigation of the effect of some drilling operational parameters on the development of the wellbore natural fracture also demonstrated that the drillstring vibration cyclic loads lead to an increase of the fracture length, fracture width, the loss circulation and the Bottom Hole Pressure. This study couples the integration of the fracture rock development with the continuous cyclic load generated by drill string vibrations. This aspect has been rarely discussed in the literature. The study indicates that the cyclic loads significantly affect the development of the wellbore natural fracture during drilling operations, and therefore has an important impact on the wellbore stability analysis.

Effect of Formations Compressive Strength on Drill String Vibrations

2013 ◽  
Author(s):  
Abdolali Esmaeili ◽  
Behzad Elahifar ◽  
Rudolf K. Fruhwirth ◽  
Gerhard Thonhauser
Keyword(s):  
Compressive Strength ◽  
Drill String ◽  
String Vibrations
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