Modeling and Analysis of Drillstring Vibration in Riserless Environment

2012 ◽  
Vol 135 (1) ◽  
Author(s):  
Robello Samuel
Keyword(s):  
Mathematical Formulation ◽  
Careful Consideration ◽  
Operating Conditions ◽  
Drilling Process ◽  
Analysis Model ◽  
Modeling And Analysis ◽  
Bending Stresses ◽  
Downhole Tool ◽  
Lateral Displacements ◽  
Well Data

Riserless drilling poses numerous operational challenges that adversely affect the efficiency of the drilling process. These challenges include increased torque and drag, buckling, increased vibration, poor hole cleaning, tubular failures, poor cement jobs, and associated problems during tripping operations. These challenges are closely associated with complex bottomhole assemblies (BHAs) and the vibration of the drillstring when the topholes are drilled directionally. Current methods lack proper modeling to predict drillstring vibration. This paper presents and validates a modified model to predict severe damaging vibrations, analysis techniques, and guidelines to avoid the vibration damage to BHAs and their associated downhole tools in the riserless highly deviated wells. The dynamic analysis model is based on forced frequency response (FFR) to solve for resonant frequencies. In addition, a mathematical formulation includes viscous, axial, torsional, and structural damping mechanisms. With careful consideration of input parameters and judicious analysis of the results, the author demonstrates that drillstring vibration can be avoided by determining the 3D vibrational response at selected excitations that are likely to cause them. The analysis also provides an estimate of relative bending stresses, shear forces, and lateral displacements for the assembly used. Based on the study, severe vibrations causing potentially damaging operating conditions were avoided, which posed a major problem in the nearby wells. The study indicates that the results are influenced by various parameters, including depth of the mud line, offset of the wellhead from the rig center, wellbore inclination, curvature, wellbore torsion, and angle of entry into the wellhead. This study compares simulated predictions with actual well data and describes the applicability of the model. Simple guidelines are provided to estimate the operating range of the drilling parameter to mitigate and avoid downhole tool failures.

DrillString Vibration With Hole-Enlarging Tools: Analysis and Avoidance

2013 ◽  
Vol 135 (3) ◽  
Author(s):  
Robello Samuel ◽  
Dongping Yao
Keyword(s):  
Vibration Analysis ◽  
Mathematical Formulation ◽  
Three Dimensional ◽  
Technical Conference ◽  
Careful Consideration ◽  
Operating Conditions ◽  
Drilling Process ◽  
Analysis Model ◽  
Incidence Data ◽  
Lateral Displacements

In high-risk, high-cost environments, such as ultra-deep waters, refining advanced technologies for the successful completion of wells is paramount. Challenges are still very much associated with complex bottomhole assemblies (BHAs) and with the vibration of the drillstring when used with hole enlarging tools. These tools with complex profiles and designs become additional excitation sources of vibration. The more widespread use of downhole tools for both directional telemetry and logging-while-drilling (LWD) applications, as part of the front line data acquisition system within the drilling process, has made reliability a prime area of importance. This paper presents and validates an existing model to predict severe damaging vibrations. It also provides analysis techniques and guidelines to successfully avoid the vibration damage to downhole tools and to their associated downhole assemblies when using hole enlarging tools, such as hole openers and underreamers. The dynamic analysis model is based on forced frequency response (FFR) to solve for resonant frequencies. In addition, a mathematical formulation includes viscous, axial, torsional, and structural damping mechanisms. With careful consideration of input parameters and the judicious analysis of results, we demonstrated that drillstring vibration can be avoided by determining the three-dimensional vibrational response at selected excitations that are likely to cause them. In addition, the analysis provides an estimate of relative bending stresses, shear forces, and lateral displacements for the assembly used. Based on the study, severe vibrations causing potentially damaging operating conditions that had been a major problem in nearby wells were avoided. Steps required to estimate the operating range of the drilling parameter such as weight on bit and rotational speeds to mitigate and avoid the downhole tool failures due to vibration are given. Extensive simulations were performed to compare the data from the downhole vibration sensors; this paper includes severe vibration incidence data from three case studies in which the model estimated, predicted, and avoided severe vibration (Samuel, R., et al., 2006, “Vibration Analysis Model Prediction and Avoidance: A Case History,” Paper SPE 102134 Presented at the IADC India Conference, Mumbai, India, Oct. 16–18; Samuel, R., 2010, “Vibration Analysis for Hole Enlarging Tools” SPE 134512, Annual Technical Conference, Florence, Italy).

Coupled multi-DOF dynamic contact analysis model for the simulation of intermittent gear tooth contacts, impacts and rattling considering backlash and variable torque

2015 ◽  
Vol 230 (7-8) ◽  
pp. 1022-1047 ◽  
Author(s):  
C Spitas ◽  
V Spitas
Keyword(s):  
Numerical Models ◽  
Gear Tooth ◽  
Dynamic Contact ◽  
Spur Gear ◽  
Accurate Solution ◽  
Operating Conditions ◽  
Analytical Models ◽  
Analysis Model ◽  
Tooth Contact ◽  
Lateral Displacements

Variable torque conditions in geared powertrain applications are known to lead to tooth contact loss, contact reversal, tooth impacts, rattling vibration and noise. Displacements/ deflections dominate the low-torque high-vibration responses and, besides backlash, the real-time dynamic lateral deflections of the gear bodies and the occurrence of simultaneous double-sided tooth contact influence the instantaneous mesh excitation strongly. The faster deterministic and stochastic analytical models do not consider this coupling, whereas the numerical models that do so implicitly by simulating the contact of discretised tooth surfaces/ volumes are significantly limited by the accuracy and computational overhead of their discrete meshes. To provide a both fast and accurate solution of the contact problem, especially in displacement-dominated operating conditions, this work analyses the dynamic contact of gears starting from basic principles and derives an accurate analytical model for the coupling between the compliance, contact geometry, the backlash, and the torsional and lateral displacements and deflections in the general three-dimensional multi-DOF system. This serves as a foundation for a series of dynamical simulations of a single-stage spur gear transmission under different variable-torque excitations to predict tooth contact loss and contact reversal and the basic interactions that lead to impacts and rattling vibration. This approach can be used to predict critical torque fluctuation levels, beyond which these phenomena emerge.

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.

Model of vibration in drilling into fibre-reinforced composite materials

2009 ◽  
Vol 223 (9) ◽  
pp. 1107-1114
Author(s):  
B W Huang
Keyword(s):  
Composite Materials ◽  
Vibration Amplitude ◽  
Time Dependent ◽  
Process Time ◽  
Drilling Process ◽  
Improve Product Quality ◽  
Analysis Model ◽  
Inhomogeneous Materials ◽  
Reinforced Composite ◽  
Twisted Beam

A model of the dynamic drill characteristics while drilling through fibre-reinforced composite materials (FRCMs) is investigated in this study. Anisotropic and inhomogeneous materials such as FRCMs, which are used to improve product quality, make it possible to improve production rate and avoid drill breakage. Such materials were used to study the dynamic characteristics of the drilling process. A theoretical analysis model for drilling composite materials is proposed. A pre-twisted beam is used to simulate the drill. A moving Winkler-type elastic foundation is used to approximate the drilling process time-dependent boundary. Numerical analysis indicates that the vibration amplitude changes significantly as the drill moves through composite material.

scholarly journals Modeling and Analysis of a Ship’s Diesel Engine Thermal System

2020 ◽  
Vol 165 ◽  
pp. 06039
Author(s):  
Chen Zuotian ◽  
Lu Jia ◽  
Dong Qingfeng ◽  
Hu cun
Keyword(s):  
Diesel Engine ◽  
Simulation Models ◽  
Operating Conditions ◽  
Pipeline System ◽  
Thermal System ◽  
Thermal Coupling ◽  
Modeling And Analysis ◽  
Temperature Changes ◽  
Modular Model ◽  
System Nodes

This article takes the diesel thermal system as the research object, which simplifies the diesel engine system into four subsystems. This article conducts a thermodynamic analysis of the specific equipment of the host thermal system. Simulink tools in MATLAB are used to build simulation models of specific equipment in the thermal system, and a modular model is used to build a subsystem model based on the specific equipment model. Then, the thermal coupling relationship between the subsystems is used to form the thermal system. The overall model obtains the temperature values of the key nodes of the thermal system network, so that it can predict the temperature changes of the thermal pipeline system nodes of the diesel engine under various operating conditions.

Semi-Quantitative Reliability-Based Ranking Method for Assessment of Pipeline Dents With Stress Risers

2018 ◽  
Author(s):  
Doug Langer ◽  
Sherif Hassanien ◽  
Janine Woo
Keyword(s):  
Complex Geometry ◽  
Limit State ◽  
Operating Conditions ◽  
Pipeline System ◽  
Element Analysis ◽  
Modeling And Analysis ◽  
Base Level ◽  
Stress Risers ◽  
Short Period ◽  
Detailed Assessment

Current regulations for prediction and management of potential delayed failures from existing pipeline dents rely primarily on depth and conservative assumptions related to threat interactions, which have shown limited correlation with industry failures. Such miscorrelation can lead to challenges in managing effectiveness and efficiency of pipeline integrity programs. Leading integrity techniques that entail detailed assessment of complex dent features rely on the use of finite element analysis, which tends to be inefficient for managing large pipeline systems due to prohibitively complex modeling and analysis procedures. While efforts are underway to improve dent assessment models across the industry, these often require significant detailed information that might not be available to operators; moreover, they suffer scattered model error which makes them susceptible to unclear levels of conservatism (or non-conservatism). Nevertheless, most techniques/models are deterministic in nature and neglect the effect of both aleatory and epistemic uncertainties. Operators typically utilize conservative assumptions based on subject matter experts’ opinions when planning mitigation programs in order to account for different types of uncertainties associated with the problem. This leads to inefficient dig programs (associated with significant costs) while potentially leaving dents on the pipeline which cannot be quantitatively risk assessed using current approaches. To address these concerns, the problem calls for a dent assessment framework that balances accuracy with the ability to assess dent and threat integration features at a system-wide level with available information in a practical timeframe that aligns with other integrity programs. This paper expands upon the authors’ previously published work regarding a fully quantitative reliability-based methodology for the assessment of dents interacting with stress risers. The proposed semi-quantitative reliability model leverages a strain-based limit state for plain dents (including uncertainty) with semi-quantitative factors used to account for complex geometry, stress riser interactions, and operating conditions. These factors are calibrated to reliability results from more detailed analysis and/or field findings in order to provide a simple, conservative, analytical-based ranking tool which can be used to identify features that may require more detailed assessment prior to mitigation. Initial validation results are provided alongside areas for continued development. The proposed model provides sufficient flexibility to allow it to be tailored/calibrated to reflect specific operator’s experience. The model allows for a consistent analysis of all types of dent features in a pipeline system in a short period of time to support prioritization of features while providing a base-level likelihood assessment to support calculation of risk. This novel development supports a dent management framework which includes multiple levels of analysis, using both deterministic and probabilistic techniques, to manage the threat of dents associated with stress risers across a pipeline system.

scholarly journals Nonlinear Modeling and Analysis of Pressure Wave inside CEUP Fuel Pipeline

2014 ◽  
Vol 2014 ◽  
pp. 1-11 ◽  
Author(s):  
Qaisar Hayat ◽  
Liyun Fan ◽  
Enzhe Song ◽  
Xiuzhen Ma ◽  
Bingqi Tian ◽  
...  
Keyword(s):  
Wave Equation ◽  
Pressure Wave ◽  
Fuel Injection ◽  
Nonlinear Modeling ◽  
Operating Conditions ◽  
Fuel Properties ◽  
Injection System ◽  
Modeling And Analysis ◽  
Large Pressure ◽  
Realistic Description

Operating conditions dependent large pressure variations are one of the working characteristics of combination electronic unit pump (CEUP) fuel injection system for diesel engines. We propose a precise and accurate nonlinear numerical model of pressure inside HP fuel pipeline of CEUP using wave equation (WE) including both viscous and frequency dependent frictions. We have proved that developed hyperbolic approximation gives more realistic description of pressure wave as compared to classical viscous damped wave equation. Frictional effects of various frequencies on pressure wave have been averaged out across valid frequencies to represent the combined effect of all frequencies on pressure wave. Dynamic variations of key fuel properties including density, acoustic wave speed, and bulk modulus with varying pressures have also been incorporated. Based on developed model we present analysis on effect of fuel pipeline length on pressure wave propagation and variation of key fuel properties with both conventional diesel and alternate fuel rapeseed methyl ester (RME) for CEUP pipeline.

Parametric Modeling and Analysis of Self-Loading Container Vehicle Based on ANSYS

2014 ◽  
Vol 620 ◽  
pp. 137-142
Author(s):  
Wen Bin Wang ◽  
Kai Cheng ◽  
Lei Cheng
Keyword(s):  
Parametric Modeling ◽  
Operating Conditions ◽  
Design Stage ◽  
Original Structure ◽  
Modeling And Analysis ◽  
Domestic Enterprise ◽  
Technical Requirements ◽  
Design Cycle ◽  
Research Achievement ◽  
New Generation

For the technical requirements of a domestic enterprise to develop a new generation of self-loading container truck products, this paper creatively puts forward a set of suitable reduction standards for special structure. Based on ANSYS and Visual Studio 2008 platform, the parametric modeling and automatic analysis of side loader container structure are achieved independently. Several operating conditions, such as stacking, self-loading and unloading etc. can be analyzed rapidly and automatically. The research achievement can be not only used for the conceptual design stage of forward design process, but also applied in the modification of the original structure, thus effectively shortening the product design cycle, reducing design cost, providing useful guidance for independent research of domestic enterprise.

The Design Method of V-Tooth Coupling

2013 ◽  
Vol 871 ◽  
pp. 347-351
Author(s):  
Dun Cai Lei ◽  
Jin Yuan Tang
Keyword(s):  
Finite Element ◽  
Design Method ◽  
Operating Conditions ◽  
Bending Stress ◽  
Analysis Model ◽  
Element Analysis ◽  
Finite Element Analysis Model ◽  
Precision Design ◽  
The Finite Element Analysis ◽  
Paper Work

A lecture on the method to compute the the stress of V-tooth coupling under the actual operating conditions. the finite element analysis model of V-tooth coupling under the preload, axial load and torsion was established by used of the software ABAQUS,and the distribution of the bending stress at the root was obtained. The analytical method to compute the bending stress of V-tooth disk is deduced based on the basic principle of material mechanics, and the relative error within 10% compared with the results of finite element analysis.The paper work provide the reference for the precision design of V-tooth coupling.

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