Pdf drill string vibration modeling including coupling effects. Another survey of approaches for stickslip vibration suppression has been presented by zhu et al. Schematic of the drillstring model with a lumped mass. Pdf mathematical modeling and analysis of drill string. Drillstring vibrations and vibration modeling vibration types bit bounce drillstring vibrations can be divided into three types, or modes. Parameters name results density of drill string kgm 3. Simulation shows that the responses under random excitation become random. The first and second members define a first and a second chamber for holding the fluid. A system for damping vibration i n a drill string can include a valve assembly having a supply of a fluid, a first member, and a second member capable of moving in relation to first member in response to vibration of the drill bit. Research article nonlinear model and qualitative analysis. Us7997357b2 system and method for damping vibration in a.
Drill string vibration is inevitable low levels are usually harmless severe vibrations are destructive vibrations can be controlled to a degree. Torsional vibrations can cause irregular downhole rotation. An analytical study of drill string vibrations onepetro. Download milwaukee tool operators manuals, service parts kits and wiring instructions and msds documents. Static bending stresses in catenaries and drill strings j. It is composed of thin tubes drill pipes and thicker tubes drill collars with a bit fixed at the end. Figure 2 shows a time history of the downhole angular velocity, calculated from the magnetometer signals. Iust international journal of engineering science, vol.
One or more vibration damping modules are also spaced along the length of the drill string. An apparatus and method for damping vibration, especially torsional vibration due to stickslip, in a drill string, sensors measure the instantaneous angular velocity of the drill string at one or more locations along the length of the drill string. Shock and vibration table of contents 2017 shock and vibration publishes papers on all aspects of shock and vibration, especially in relation to civil, mechanical and aerospace engineering applications, as well as transport, materials and geoscience. Other downhole drill string components, like mwd lwd tools, also benefit from lower vibration. A broad survey of drill string vibration modeling literature was presented by ghasemloonia et al.
Research article mathematical modeling and analysis of. Axial vibrations can cause bit bounce, which may damage bit cutters and bearings. Research article chaotic vibration analysis of the bottom. Fluid can flow between the first and second chambers in. This project investigates characteristics of vibration of a drillstring under the action of weight on bit and drillstring rotation. Mathematical modeling and analysis of drill string longitudinal vibration with lateral inertia effect article pdf available in shock and vibration 20162. The drill collar is assumed to be rigid in torsional vibration since the collars are much stiffer than the drill pipe. The drill string is connected to the vibration generation device proposed in this study, and it is another purpose of this study to analyze the effect of vibration on. On lump mass torsional vibration model and helical deformation of. Drill string vibration modeling including coupling effects. Pdf drill string vibration modeling including coupling. A proxy for identifying lithologic boundaries while drilling article pdf available may 2002 with 76 reads how we measure reads. Minimising drillstring vibrations during the drilling of slim and conventional holes means that the dynamic components of the loads in the drillstring are reduced, with the following. The random excitation is caused by the random friction coefficients between the drill bit and the bottom of the hole and assumed as white noise.
Nonlinear instabilities and control of drillstring stick. Drillstring vibrations and vibration modeling product sheet. In the beginning of oil exploration there were mainly vertical wells, but nowadays directional horizontal drilling is very common 1, 2. Step response of the linear infinitedimensional axial drill string described by the frequency response function g a s. Equipment, associated with directional drilling has become more and more complex and vulnerable to every mode of vibration. Drillstring vibrations and vibration modeling product. In order to being able to guide a drillstring in any direction, came the significant task of modelling the whole process mathematically and physically. Reliability and maintainability have become important considerations in downhole tool design. Pdf the governing equations of motion for a drill string considering coupling between axial, lateral and. The ipdt has demonstrated 50% improvements in rate of penetration rop and doubling of bit life in the field due to reduced vibration.
On lump mass torsional vibration model and helical deformation of drill string. The soft torque controller, which was patented by shell in 1992, is widely used in industry e. T he bitformation interactions are assumed to be related to the following parameters. Drill strings, dynamics mechanics, vibration control. With a goal of damping the first mode of torsional motion, this controller was essentially a proportionalintegral. Vibration characteristics analysis and experimental study of new. Drillstring horizontal dynamics with uncertainty on the. Us9458679b2 apparatus and method for damping vibration. Longitudinal and angular drillstring vibrations with. Ind february, 1967 effect of tool joints on passages of plane longitudinal and torsional waves along a drill pipe.
Moreover, impacts with the borehole wall tend to form the over gauge hole or produce problems with directional control of the well as well as increasing the surface torque aldred. Modeling and analysis of stickslip vibration and bit bounce in. Analysis and control of oilwell drilling vibrations a timedelay. Drillstring vibration is a major contributor to downhole tool failure. Us8944190b2 system and method for damping vibration in a. Objectives understanding drill string vibrations types of vibrations and consequences recognizing and dealing with vibrations. For the physical model used to explain the axial vibration on a drill string. An analytical study of drillstring vibration journal of. In order to avoid or minimize the impact of vibrations on operation conditions it is essential a deep dynamical investigation that allows a proper understanding of system dynamics. In new drilling conditions such as extended reach drilling or long horizontal well, to avoid large friction between drill string and wellbore or weigh on bit. This approximation is generally accepted and appears to give adequate results for the drill string vibration problem. Pdf on lump mass torsional vibration model and helical. Pdf drillstring vibration analysis using nonsmooth. Using a finite element model, this paper investigates the torsional vibration of a drill string under combined deterministic excitation and random excitation.
The drill string is composed of drill pipe, heavy weight drill pipe, drill collars and other components like stabilizers and drilling jars. This paper presents experimental and numerical investigations of the complex drill string vibration, with particular attention to the helical buckling of drillstrings. Vibration types drillstring vibrations can be divided into three types, or modes. The destructive nature of each type of vibration is different. A survey of the literature related to theoretical and experimental studies on stick slip vibration in oilwell drillstring is carried out in this study. After analyzing the influence of random vibrations in the drill string, will divide them into a narrowband and broadband vibrations. Ep3524944a1 vibration detection in a drill string based. Recently khulief and alnaser 10 derived a finite element formulation representing the. Drill string vibrations the existence of substantial vibrations in the drillstring have caused much trouble time during drilling in slim and conventional holes. Modeling friction performance of drill string torsional. Drill string axial vibration and sonic head analysis. This energy boosts the amplitude of string vibration, increases bending and impacts with the borehole, and leads to early fatigue of tools and reduction of bit life. In order to mitigate the undesired drill string vibration, different control schemes have been proposed and implemented.
Tricone bits operation manual rotary drilling tools iadc codes product features blast hole rotary bits rotary drill string 251mm 9 78. Oil drilling operations is usually associated with drill string severe vibration conditions that lead to an onerous and inefficient process. 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. Drill string vibration is a very prevalent phenomenon. The angular velocity at the surface v, wob and other parameters were almost. It may also cause hole damage and increase the need for more frequent rig repair. A drillstring is a slender structure used to drill rocks in search of oil. Modeling friction performance of drill string torsional oscillation using dynamic friction model. Timely detection and mitigation of downhole vibration is key to avoiding nonproductive time npt and preventing equipment damage. The pilot sensor is used to record the axial vibrations that travel up the drill string, representing the drill. Coupled axialtorsional vibrations of drill strings by means of nonlinear model j. Table of contents download pdf acknowledgements references. Download operators manuals, parts lists, msds milwaukee.
The bottom hole assembly bha is the components used above the bit without taking in consideration the drill pipe. We investigate experimentally and numerically suppression of drill string torsional vibration while drilling by using a sliding mode control. Analysis of vibration efficiency of drill string using the. Drillstring vibration analysis using nonsmooth dynamics approach. Three types of vibration, which are axial, lateral and torsional vibrations exist in the drill string. The problem of drill string vibration occurs in drilling operations and it will affect the usage life of drill pipe and drill bits. Drillstring dynamics and vibration control oilwell. The experiments are conducted on the novel experimental drill string dynamics rig developed at the university of aberdeen wiercigroch, m. Pdf in the present work, nonlinear vibrations of drill strings are studied. Stick slip and vibration mitigated while drilling by the use of ast from tomax as duration. When the drillstring is in a higherlength, the stickslip frequency is at a lower level. Rotary drilling tools black diamond drilling canada. The drillstring means the tubulars and the accessories used to run the drill bit to the bottom.