Mechanisms and Mitigation of 3D Coupled Vibrations in Drilling with PDC Bits

2021 ◽  
Author(s):  
Shilin Chen ◽  
Chris Propes ◽  
Curtis Lanning ◽  
Brad Dunbar
Keyword(s):  
Torsional Oscillation ◽  
Excitation Frequency ◽  
Low Frequency ◽  
Coupled Vibration ◽  
Stick Slip ◽  
Rock Interaction ◽  
Bottom Hole ◽  
New Type ◽  
Design Characteristics ◽  
Axial Resonance

Abstract In this paper we present a new type of vibration related to PDC bits in drilling and its mitigation: a vibration coupled in axial, lateral and torsional directions at a high common frequency (3D coupled vibration). The coupled frequency is as high as 400Hz. 3D coupled vibration is a new dysfunction in drilling operation. This type of vibration occurred more often than stick-slip vibration. Evidences reveal that the coupled frequency is an excitation frequency coming from the bottom hole pattern formed in bit/rock interaction. This excitation frequency and its higher order harmonics may excite axial resonance and/or torsional resonance of a BHA. The nature of 3D coupled vibration is more harmful than low frequency stick-slip vibration and high frequency torsional oscillation (HFTO). The correlation between the occurrence of 3D coupled vibration and bit design characteristics is studied. Being different from prior publications, we found the excitation frequency is dependent on bit design and the occurrence of 3D coupled vibration is correlated with bit design characteristics. New design guidlines have been proposed to reduce or to mitigate 3D coupled vibration.

Model Development of Torsional Drillstring and Investigating Parametrically the Stick-Slips Influencing Factors

2012 ◽  
Vol 135 (1) ◽  
Author(s):  
Parimal Arjun Patil ◽  
Catalin Teodoriu
Keyword(s):  
Nonlinear Differential Equations ◽  
Torsional Oscillation ◽  
Stick Slip ◽  
Friction Forces ◽  
Rock Interaction ◽  
Torsional Oscillations ◽  
Drilling Performance ◽  
Bottom Hole ◽  
Drilling Parameters ◽  
Bottom Hole Assembly

Drillstring vibration is one of the limiting factors maximizing drilling performance. Torsional vibrations/oscillations while drilling is one of the sever types of drillstring vibration which deteriorates the overall drilling performance, causing damaged bit, failure of bottom-hole assembly, overtorqued tool joints, torsional fatigue of drillstring, etc. It has been identified that the wellbore-drillstring interaction and well face-drill bit interaction are the sources of excitation of torsional oscillations. Predrilling analysis and real time analysis of drillstring dynamics is becoming a necessity for drilling oil/gas or geothermal wells in order to optimize surface drilling parameters and to reduce vibration related problems. It is very challenging to derive the drillstring model considering all modes of vibrations together due to the complexity of the phenomenon. This paper presents the mathematical model of a torsional drillstring based on nonlinear differential equations which are formulated considering drillpipes and bottom-hole assembly separately. The bit–rock interaction is represented by a nonlinear friction forces. Parametric study has been carried out analyzing the influence of drilling parameters such as surface rotations per minute (RPM) and weight-on-bit (WOB) on torsional oscillations. Influences of properties of drillstring like stiffness and inertia, which are most of the times either unknown or insufficiently studied during modeling, on torsional oscillation/stick-slip is also studied. The influences of different rock strength on rate of penetration (ROP) considering the drilling parameters have also been studied. The results show the same trend as observed in fields.

Stick-slip investigation of dual drilling and reaming bottom hole assembly

2021 ◽  
pp. 095440622110184
Author(s):  
Mohammed F Al Dushaishi ◽  
Mortadha T Alsaba ◽  
Ahmed K Abbas ◽  
Tariq Tashtoush
Keyword(s):  
Field Studies ◽  
Drill Bit ◽  
Coupled Vibration ◽  
Stick Slip ◽  
Premature Failure ◽  
Bottom Hole ◽  
Vibration Model ◽  
Dual Action ◽  
Bottom Hole Assembly ◽  
Element Approach

Drillstring vibration is known to cause failures of drilling equipment, including the drill bit. In particular, stick-slip vibration has been known for causing premature failure of the drill bit, hence resulting in reducing the rate of penetration. With dual reaming while drilling, cutting forces are acting on the drillstring due to the simultaneous contact of the reamer and the drill bit. Field studies have shown dramatic changes in the dynamics of the bottom hole assembly due to the dual cutting actions. This paper investigates the dynamics of bottom hole assembly for dual reaming and drilling operation, with emphasis on stick-slip vibrations due to the reamer and the bit contact with the formation. A coupled vibration model representing the drillstring was created to simulate the stick-slip vibrations caused by the bit and reamer interactions using the finite element approach. The numerical analysis showed an elevated stick-slip vibration due to the dual-action of the reamer and the bit. Sensitivity analysis indicated that the cutter aggressiveness for the bit and the reamer are the most significant parameters affecting stick-slip behavior.

The Effect of Stick Slip Vibration on the Backward Whirl of Bottom Hole Assembly in Drillstring

2016 ◽  
Author(s):  
Dapeng Zhao ◽  
Sigve Hovda ◽  
Sigbjørn Sangesland
Keyword(s):  
Torsional Vibration ◽  
Borehole Wall ◽  
Stick Slip ◽  
Rock Interaction ◽  
Bottom Hole ◽  
Nonlinear Contact ◽  
Backward Whirl ◽  
Bottom Hole Assembly ◽  
Rotary Speed ◽  
Drill Collar

The whirl phenomena in the bottom hole assembly (BHA) is believed to be formed by the imbalance of the rotational drill collar. Backward whirl is caused by the nonlinear contact between the BHA and the borehole, and can be extremely damaging to the down hole tools and borehole. In the previous studies, a two-degrees-of-freedom lumped parameter model is developed for representing the drill collar in lateral motions (whirl). Due to the bit-rock interaction, the stick slip torsional vibration is very common. In the current work, therefore, the torsional vibration causing fluctuation of rotary speed is taken into account. The simulation results indicate that the drill collar whirls forward at lower constant rotary speed. With increasing rotary speed, the backward whirl is activated by the contact between the drill collar and the borehole wall. The nonlinear contact forces obey the Hertzian contact law, which led to lateral bounce of the drill collar and impact borehole wall chaotically. The modified Karnopp friction model is adopted to simulate the stick slip rotary vibration of the BHA. The different characters of lateral vibrations are identified by a power spectrum density diagram with and without consideration of the stick slip vibration.

Dynamic Modelling of Horizontal Shafts With Annular Surface Contact and Friction: Application to Oilwell Drilling

2014 ◽  
Author(s):  
Md. Mejbahul Sarker ◽  
D. Geoff Rideout ◽  
Stephen D. Butt
Keyword(s):  
Three Dimensional ◽  
Dynamic Modelling ◽  
Lateral Vibration ◽  
Horizontal Section ◽  
Stick Slip ◽  
Rock Interaction ◽  
Bottom Hole ◽  
Proposed Model ◽  
Bottom Hole Assembly ◽  
Friction Dynamics

Lateral whirl vibrations in long sections of horizontal oilwell drillstrings, which are essentially enclosed shafts lying on the low side of the wellbore, are potentially destructive to the bit, pipes and downhole tools. Forward or backward whirl can lead to impact with the borehole, and stick slip and bit bounce can cause tool joint failure, twist-off, and bit damage. A complete deviated drillstring has been modelled by having decoupled axial and torsional segments for the vertical and curved portions, and nonlinear three-dimensional multibody segments with lateral vibration in the final horizontal section ending at the bit. The model can predict how axial and torsional bit-rock reactions are propagated to the surface, and the role that lateral vibration near the bit plays in exciting those vibrations and stressing components in the bottom-hole-assembly. The proposed model includes the mutual dependence of these vibrations, which arises due to bit-rock interaction and friction dynamics between the drillstring and wellbore wall.

scholarly journals Kinematics and dynamics analysis of new rotary-percussive PDM drilling tool

2021 ◽  
pp. 146134842198915
Author(s):  
Jialin Tian ◽  
Xuehua Hu ◽  
Liming Dai ◽  
Lin Yang ◽  
Yi Yang ◽  
...  
Keyword(s):  
Drill String ◽  
Structure Design ◽  
Drilling Process ◽  
Analysis Model ◽  
Drilling Tool ◽  
Stick Slip ◽  
Rate Of Penetration ◽  
Bottom Hole ◽  
Bottom Hole Assembly ◽  
The Impact

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.

A periodic seismic isolation foundation with an extremely broad low-frequency attenuation zone: Theoretical analysis and experimental verification

2021 ◽  
pp. 136943322110646
Author(s):  
Peng Zhou ◽  
Shui Wan ◽  
Xiao Wang ◽  
Yingbo Zhu ◽  
Muyun Huang
Keyword(s):  
Seismic Isolation ◽  
Seismic Waves ◽  
Periodic Structures ◽  
Finite Size ◽  
Low Frequency ◽  
Bridge Structure ◽  
Engineering Structures ◽  
P Waves ◽  
New Type ◽  
Dominant Frequencies

The attenuation zones (AZs) of periodic structures can be used for seismic isolation design. To cover the dominant frequencies of more seismic waves, this paper proposes a new type of periodic isolation foundation (PIF) with an extremely wide low-frequency AZ of 3.31 Hz–17.01 Hz composed of optimized unit A with a wide AZ and optimized unit B with a low-frequency AZ. The two kinds of optimized units are obtained by topology optimization on the smallest periodic unit with the coupled finite element-genetic algorithm (GA) methodology. The transmission spectra of shear waves and P-waves through the proposed PIF of finite size are calculated, and the results show that the AZ of the PIF is approximately the superposition of the AZs of the two kinds of optimized units. Additionally, shake tests on a scale PIF specimen are performed to verify the attenuation performance for elastic waves within the designed AZs. Furthermore, numerical simulations show that the acceleration responses of the bridge structure with the proposed PIF are attenuated significantly compared to those with a concrete foundation under the action of different seismic waves. Therefore, the newly proposed PIF is a promising option for the reduction of seismic effects in engineering structures.

An Innovative Approach of Using Engineering Modelling to Improve Drilling Dynamics in Western Rajasthan, India

2021 ◽  
Author(s):  
Shailesh Prakash ◽  
Mohammad Zayyan ◽  
Ole Gjertsen ◽  
Manuel Centeno Acuna ◽  
Piyush Kumar Kulshrestha ◽  
...  
Keyword(s):  
Torsional Oscillation ◽  
Predictive Modelling ◽  
Integrated Approach ◽  
Vibration Monitoring ◽  
Hole Drilling ◽  
Volcanic Complex ◽  
Gas Field ◽  
Stick Slip ◽  
Unique Type ◽  
Barmer Basin

Abstract Raageshwari Deep Gas (RDG) field is a major gas field in the Barmer Basin of Rajasthan, India which comprises of a tight gas-condensate reservoir within the underlying thick Volcanic Complex. The Volcanic Complex comprises two major units – upper Prithvi Member (Basalt) and lower Agni Member (Felsics interbedded with older basalt). The production zone is drilled in 6" and has historically seen high level of shock & vibrations (S&V) and stick-slip (S&S) leading to multiple downhole tool failures and poor rate of penetration (ROP). Individual changes in Bit and bottom hole drilling assembly (BHA) design were not able to give satisfactory results and hence an integrated approach in terms of in-depth formation analysis, downhole vibration monitoring, correct predictive modelling, bit and BHA design was required. A proprietary formation analysis software was used to map the entire RDG field to understand the variation in terms of formation compactness, abrasiveness and impact (Figure 1,2,3 & 4). The resulting comprehensive field map thus enabled us to accurately identify wells that would be drilling through more of problematic Felsics and where higher S&V and S&S should be expected. To better understand the vibrations at the point of creation, i.e., bit, a downhole vibration recording tool was used to record vibration & stick-slip data at a frequency of 1024Hz. This tool picked up indication of a unique type of vibration occurring downhole known as High Frequency Torsional Oscillation (HFTO), that was quite detrimental to the health of bit and downhole tools. A proprietary predictive modelling software was used to optimize the bit-BHA combination to give least amount of S&V and S&S. Data from the downhole vibration recording tool, formation mapping software and offset bit designs was used to design a new bit with ridged diamond element cutters and conical diamond element cutters to drill through the highly compressive and hard basalt. The predictive modelling software identified a motorized Rotary steerable assembly (RSS) to give the best drilling dynamics with the newly designed bit. The software predicted much lower S&V and S&S with higher downhole RPM which was possible with the help of motorized RSS. Implementing the above recommendations from the various teams involved in the project, drilling dynamics was vastly improved and ROP improvement of about 45% was seen in the field. This combination was also able to drill the longest section of Felsics (826m) with unconfined compressive strengths as high as 50,000 psi in a single run with excellent dull condition of 0-1-CT-TD This paper will discuss in detail the engineering analyses done for improving drilling dynamics in field along with how HFTO was identified in field and what steps were taken to mitigate it.

New Type of Hydraulic Rotary Actuator; Development and Application in a Large Telerobotic Manipulator System

2001 ◽  
Author(s):  
John R. Haas
Keyword(s):  
Modular Design ◽  
Large Diameter ◽  
Stick Slip ◽  
Precision Motion Control ◽  
Constant Torque ◽  
Rotary Actuator ◽  
Continuous Rotation ◽  
Potential Applications ◽  
New Type ◽  
Precision Motion

Abstract This paper describes a new type of hydraulic rotary actuator specifically developed to provide precision motion control in a very large, man rated, underwater telerobotic manipulator system. The high pressure, high torque rotary actuators are hydrostatically balanced, provide continuous rotation, constant torque output, exhibit minimal “stick-slip” and zero backlash. It is believed that the combination of features and the performance exhibited by these actuators represent an improvement in actuator technology to such an extent as to make projects previously determined unfeasible, now practical. Features of particular design value are a very large diameter through bore, and a truly modular design permitting use as an integral structural member. This paper will address design rationale, operating principles, key design features, product development highlights, an astronaut trainer case study, future development and potential applications.

A Semi-Analytical Study of Stick-Slip Oscillations in Drilling Systems

2010 ◽  
Vol 6 (2) ◽  
Author(s):  
B. Besselink ◽  
N. van de Wouw ◽  
H. Nijmeijer
Keyword(s):  
Dynamic Analysis ◽  
Limit Cycle ◽  
Analytical Approach ◽  
String Model ◽  
Drill String ◽  
Axial Stiffness ◽  
Torsional Vibrations ◽  
Stick Slip ◽  
Rock Interaction ◽  
Stiffness And Damping

Rotary drilling systems are known to exhibit torsional stick-slip vibrations, which decrease drilling efficiency and accelerate the wear of drag bits. The mechanisms leading to these torsional vibrations are analyzed using a model that includes both axial and torsional drill string dynamics, which are coupled via a rate-independent bit-rock interaction law. Earlier work following this approach featured a model that lacked two essential aspects, namely, the axial flexibility of the drill string and dissipation due to friction along the bottom hole assembly. In the current paper, axial stiffness and damping are included, and a more realistic model is obtained. In the dynamic analysis of the drill string model, the separation in time scales between the fast axial dynamics and slow torsional dynamics is exploited. Therefore, the fast axial dynamics, which exhibits a stick-slip limit cycle, is analyzed individually. In the dynamic analysis of a drill string model without axial stiffness and damping, an analytical approach can be taken to obtain an approximation of this limit cycle. Due to the additional complexity of the model caused by the inclusion of axial stiffness and damping, this approach cannot be pursued in this work. Therefore, a semi-analytical approach is developed to calculate the exact axial limit cycle. In this approach, parametrized parts of the axial limit cycle are computed analytically. In order to connect these parts, numerical optimization is used to find the unknown parameters. This semi-analytical approach allows for a fast and accurate computation of the axial limit cycles, leading to insight in the phenomena leading to torsional vibrations. The effect of the (fast) axial limit cycle on the (relatively slow) torsional dynamics is driven by the bit-rock interaction and can thus be obtained by averaging the cutting and wearflat forces acting on the drill bit over one axial limit cycle. Using these results, it is shown that the cutting forces generate an apparent velocity-weakening effect in the torsional dynamics, whereas the wearflat forces yield a velocity-strengthening effect. For a realistic bit geometry, the velocity-weakening effect is dominant, leading to the onset of torsional vibrations.

scholarly journals Two-point observations of low-frequency waves at 67P/Churyumov-Gerasimenko during the descent of PHILAE: comparison of RPCMAG and ROMAP

2016 ◽  
Vol 34 (7) ◽  
pp. 609-622 ◽  
Author(s):  
Ingo Richter ◽  
Hans-Ulrich Auster ◽  
Gerhard Berghofer ◽  
Chris Carr ◽  
Emanuele Cupido ◽  
...  
Keyword(s):  
Low Frequency ◽  
Minimum Variance ◽  
Wave Source ◽  
Frequency Wave ◽  
Final Destination ◽  
Connection Line ◽  
New Type ◽  
Current Instability ◽  
Comet 67P ◽  
Low Frequency Waves

Abstract. The European Space Agency's spacecraft ROSETTA has reached its final destination, comet 67P/Churyumov-Gerasimenko. Whilst orbiting in the close vicinity of the nucleus the ROSETTA magnetometers detected a new type of low-frequency wave possibly generated by a cross-field current instability due to freshly ionized cometary water group particles. During separation, descent and landing of the lander PHILAE on comet 67P/Churyumov-Gerasimenko, we used the unique opportunity to perform combined measurements with the magnetometers onboard ROSETTA (RPCMAG) and its lander PHILAE (ROMAP). New details about the spatial distribution of wave properties along the connection line of the ROSETTA orbiter and the lander PHILAE are revealed. An estimation of the observed amplitude, phase and wavelength distribution will be presented as well as the measured dispersion relation, characterizing the new type of low-frequency waves. The propagation direction and polarization features will be discussed using the results of a minimum variance analysis. Thoughts about the size of the wave source will complete our study.

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