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Abdullah M. Al-shabibi - One of the best experts on this subject based on the ideXlab platform.

  • Dynamic effects of mandrel/tubular interaction on downhole solid tubular expansion in well engineering
    Journal of Energy Resources Technology-transactions of The Asme, 2009
    Co-Authors: Abdennour Seibi, S.a. Al-hiddabi, Amer S. Al-yahmadi, Ali Karrech, Tasneem Pervez, Abdullah M. Al-shabibi
    Abstract:

    The expansion process subjects a solid tubular to large plastic deformations leading to variations in tubular thickness and length, which may result in premature and unexpected failures. It was noticed that the expansion process induces wall thickness imperfections due to excessive local plastic deformation as a result of mandrel sticking and slipping relative to the expanded tubular; such irregularities increase the probability of failure. Mandrel sticking may be the result of lack of enough lubrication, tubular surface irregularities, and the presence of welded and/or threaded connections, which require higher drawing force to push the mandrel forward. When the drawing force required to overcoming the maximum static friction and the mandrel forward motion is assured, the mandrel slips relative to the expanded tubular. This “Stick-Slip” Phenomenon results in mandrel oscillations that affect the tubular response in terms of further reduction in thickness and may jeopardize the tubular capacity under normal operating field conditions. Therefore, the present work studies the mandrel dynamics and their effect on the tubular structural response. A mathematical model, which is an extension of the quasistatic tubular expansion analysis, has been developed to describe the dynamic friction effects of the Stick-Slip Phenomenon. A special case of tubular expansion consisting of 25% expansion ratio of a 4/12 in. liner hanger was considered. It was found that the level of mandrel oscillations is in the order of 1–2 mm around its equilibrium position resulting in tubular thickness reduction of approximately 9% on top of its variation caused by the steady state expansion process. This increase in thickness reduction may affect the postexpansion collapse strength of the tubular. DOI: 10.1115/1.3066412

Scott Walker - One of the best experts on this subject based on the ideXlab platform.

  • Numerical and experimental studies of stick–slip oscillations in drill-strings
    Nonlinear Dynamics, 2017
    Co-Authors: Joseph Páez Chávez, Rulston Sa, Scott Walker
    Abstract:

    The cyclic nature of the stick–slip Phenomenon may cause catastrophic failures in drill-strings or at the very least could lead to the wear of expensive equipment. Therefore, it is important to study the drilling parameters which can lead to stick–slip, in order to develop appropriate control methods for suppression. This paper studies the stick–slip oscillations encountered in drill-strings from both numerical and experimental points of view. The numerical part is carried out based on path-following methods for non-smooth dynamical systems, with a special focus on the multistability in drill-strings. Our analysis shows that, under a certain parameter window, the multistability can be used to steer the response of the drill-strings from a sticking equilibrium or stick–slip oscillation to an equilibrium with constant drill-bit rotation. In addition, a small-scale downhole drilling rig was implemented to conduct a parametric study of the stick–slip Phenomenon. The parametric study involves the use of two flexible shafts with varying mechanical properties to observe the effects that would have on stick–slip during operation. Our experimental results demonstrate that varying some of the mechanical properties of the drill-string could in fact control the nature of stick–slip oscillations.

Tasneem Pervez - One of the best experts on this subject based on the ideXlab platform.

  • Analytical model for stick–slip Phenomenon in solid tubular expansion
    Journal of Petroleum Science and Engineering, 2015
    Co-Authors: Omar S. Al-abri, S.a. Al-hiddabi, Tasneem Pervez, Sayyad Zahid Qamar
    Abstract:

    Abstract Solid tubular expansion is a metal forming process in which the inner diameter of a tube is increased to a desired value by forcing a conical mandrel through it. Large friction takes place at the mandrel/tubular interface during this operation. Typically, the static friction coefficient between two surfaces in contact is larger than the kinetic friction coefficient. If an applied force is large enough to overcome the static friction, then the reduction of the friction force to the kinetic value causes a sudden jump in the velocity of movement. This sticking and slipping of one part against the other is known as stick–slip and results in fluctuation in the force required for expansion as well as unexpected changes in length and thickness of the expanded tubular. A mathematical model depicting the dynamics of a stick–slip Phenomenon in tube expansion has been developed. Three different sets of equations (one each for stick, slip, and transition phases) are derived using equilibrium equations, incompressibility condition and Karnopp׳s friction model. A zero velocity interval is used to define stick, slip and transition phases. A MATLAB program has been written to obtain an analytical solution using the developed governing equations. Comparison between experimental and analytical results shows good agreement for various parameters such as expansion force, thickness reduction and length shortening. The proposed model gives reasonably good prediction of the stick–slip behavior observed during experimental study. The fluctuation in the displacement–time plot clearly shows sticking of the mandrel. Subsequent slipping results in more thickness reduction which can reduce the structural integrity of the tube during its service life. Sensitivity analysis shows that mandrel velocity, friction coefficient, mandrel geometry, and expansion ratio affect the thickness reduction and the force required for expansion. A careful optimum selection of these parameters is important for enhanced performance of the expandable tubular during its service life.

  • Finite element formulation for prediction and quantification of Stick-Slip Phenomenon in down-hole tubular expansion
    Volume 4A: Dynamics Vibration and Control, 2013
    Co-Authors: Omar S. Al-abri, Tasneem Pervez, Sayyad Zahid Qamar, Rashid Khan
    Abstract:

    The challenges in exploration and development of unconventional oil and gas resources are enormous. The complex reservoir characteristics, and oil and gas flow regimes introduce difficulty in predicting the oil and gas in-place, recovery and production profiles, and wells placement, design and completion. Horizontal drilling and completion using centuries-old manufacturing process of tube forming resulted in producing oil and gas from large areas with smaller footprint on the surface. Though expensive but it optimizes the recovery. The in-situ diametral expansion of tubular using a solid mandrel causes permanent deformation in which the system experiences large frictional forces at mandrel/tubular interface resulting in Stick-Slip Phenomenon. It results in varying tubular thickness and diametral eccentricity which causes structural instability in wells leading to premature failure. A finite element model describing the dynamics of Stick-Slip Phenomenon in down-hole tubular expansion was developed. Three different set of equations; one each for stick, slip and transition phases were derived using equilibrium equations, time-dependent static friction model and velocity-dependent kinetic friction model. A switch model utilizing the zero velocity interval criterion was used to define stick, slip and transition phases. The newly developed model was implemented in the finite element model by means of two user-defined subroutines namely VFRIC and VDLOAD in commercial finite element software ABAQUS. Experimental and simulation results agree well for expansion force, wall thickness reduction and tubular length shortening. It was found that the thickness variation is the most critical parameter due to its effect in lowering collapse strength of expanded tubular. Parametric study investigations showed that the effect of this Phenomenon may possibly be minimized by manipulating mandrel geometry, contact conditions, and/or mandrel speed.

  • Dynamic effects of mandrel/tubular interaction on downhole solid tubular expansion in well engineering
    Journal of Energy Resources Technology-transactions of The Asme, 2009
    Co-Authors: Abdennour Seibi, S.a. Al-hiddabi, Amer S. Al-yahmadi, Ali Karrech, Tasneem Pervez, Abdullah M. Al-shabibi
    Abstract:

    The expansion process subjects a solid tubular to large plastic deformations leading to variations in tubular thickness and length, which may result in premature and unexpected failures. It was noticed that the expansion process induces wall thickness imperfections due to excessive local plastic deformation as a result of mandrel sticking and slipping relative to the expanded tubular; such irregularities increase the probability of failure. Mandrel sticking may be the result of lack of enough lubrication, tubular surface irregularities, and the presence of welded and/or threaded connections, which require higher drawing force to push the mandrel forward. When the drawing force required to overcoming the maximum static friction and the mandrel forward motion is assured, the mandrel slips relative to the expanded tubular. This “Stick-Slip” Phenomenon results in mandrel oscillations that affect the tubular response in terms of further reduction in thickness and may jeopardize the tubular capacity under normal operating field conditions. Therefore, the present work studies the mandrel dynamics and their effect on the tubular structural response. A mathematical model, which is an extension of the quasistatic tubular expansion analysis, has been developed to describe the dynamic friction effects of the Stick-Slip Phenomenon. A special case of tubular expansion consisting of 25% expansion ratio of a 4/12 in. liner hanger was considered. It was found that the level of mandrel oscillations is in the order of 1–2 mm around its equilibrium position resulting in tubular thickness reduction of approximately 9% on top of its variation caused by the steady state expansion process. This increase in thickness reduction may affect the postexpansion collapse strength of the tubular. DOI: 10.1115/1.3066412

Abdennour Seibi - One of the best experts on this subject based on the ideXlab platform.

  • Dynamic effects of mandrel/tubular interaction on downhole solid tubular expansion in well engineering
    Journal of Energy Resources Technology-transactions of The Asme, 2009
    Co-Authors: Abdennour Seibi, S.a. Al-hiddabi, Amer S. Al-yahmadi, Ali Karrech, Tasneem Pervez, Abdullah M. Al-shabibi
    Abstract:

    The expansion process subjects a solid tubular to large plastic deformations leading to variations in tubular thickness and length, which may result in premature and unexpected failures. It was noticed that the expansion process induces wall thickness imperfections due to excessive local plastic deformation as a result of mandrel sticking and slipping relative to the expanded tubular; such irregularities increase the probability of failure. Mandrel sticking may be the result of lack of enough lubrication, tubular surface irregularities, and the presence of welded and/or threaded connections, which require higher drawing force to push the mandrel forward. When the drawing force required to overcoming the maximum static friction and the mandrel forward motion is assured, the mandrel slips relative to the expanded tubular. This “Stick-Slip” Phenomenon results in mandrel oscillations that affect the tubular response in terms of further reduction in thickness and may jeopardize the tubular capacity under normal operating field conditions. Therefore, the present work studies the mandrel dynamics and their effect on the tubular structural response. A mathematical model, which is an extension of the quasistatic tubular expansion analysis, has been developed to describe the dynamic friction effects of the Stick-Slip Phenomenon. A special case of tubular expansion consisting of 25% expansion ratio of a 4/12 in. liner hanger was considered. It was found that the level of mandrel oscillations is in the order of 1–2 mm around its equilibrium position resulting in tubular thickness reduction of approximately 9% on top of its variation caused by the steady state expansion process. This increase in thickness reduction may affect the postexpansion collapse strength of the tubular. DOI: 10.1115/1.3066412

S.a. Al-hiddabi - One of the best experts on this subject based on the ideXlab platform.

  • Analytical model for stick–slip Phenomenon in solid tubular expansion
    Journal of Petroleum Science and Engineering, 2015
    Co-Authors: Omar S. Al-abri, S.a. Al-hiddabi, Tasneem Pervez, Sayyad Zahid Qamar
    Abstract:

    Abstract Solid tubular expansion is a metal forming process in which the inner diameter of a tube is increased to a desired value by forcing a conical mandrel through it. Large friction takes place at the mandrel/tubular interface during this operation. Typically, the static friction coefficient between two surfaces in contact is larger than the kinetic friction coefficient. If an applied force is large enough to overcome the static friction, then the reduction of the friction force to the kinetic value causes a sudden jump in the velocity of movement. This sticking and slipping of one part against the other is known as stick–slip and results in fluctuation in the force required for expansion as well as unexpected changes in length and thickness of the expanded tubular. A mathematical model depicting the dynamics of a stick–slip Phenomenon in tube expansion has been developed. Three different sets of equations (one each for stick, slip, and transition phases) are derived using equilibrium equations, incompressibility condition and Karnopp׳s friction model. A zero velocity interval is used to define stick, slip and transition phases. A MATLAB program has been written to obtain an analytical solution using the developed governing equations. Comparison between experimental and analytical results shows good agreement for various parameters such as expansion force, thickness reduction and length shortening. The proposed model gives reasonably good prediction of the stick–slip behavior observed during experimental study. The fluctuation in the displacement–time plot clearly shows sticking of the mandrel. Subsequent slipping results in more thickness reduction which can reduce the structural integrity of the tube during its service life. Sensitivity analysis shows that mandrel velocity, friction coefficient, mandrel geometry, and expansion ratio affect the thickness reduction and the force required for expansion. A careful optimum selection of these parameters is important for enhanced performance of the expandable tubular during its service life.

  • Dynamic effects of mandrel/tubular interaction on downhole solid tubular expansion in well engineering
    Journal of Energy Resources Technology-transactions of The Asme, 2009
    Co-Authors: Abdennour Seibi, S.a. Al-hiddabi, Amer S. Al-yahmadi, Ali Karrech, Tasneem Pervez, Abdullah M. Al-shabibi
    Abstract:

    The expansion process subjects a solid tubular to large plastic deformations leading to variations in tubular thickness and length, which may result in premature and unexpected failures. It was noticed that the expansion process induces wall thickness imperfections due to excessive local plastic deformation as a result of mandrel sticking and slipping relative to the expanded tubular; such irregularities increase the probability of failure. Mandrel sticking may be the result of lack of enough lubrication, tubular surface irregularities, and the presence of welded and/or threaded connections, which require higher drawing force to push the mandrel forward. When the drawing force required to overcoming the maximum static friction and the mandrel forward motion is assured, the mandrel slips relative to the expanded tubular. This “Stick-Slip” Phenomenon results in mandrel oscillations that affect the tubular response in terms of further reduction in thickness and may jeopardize the tubular capacity under normal operating field conditions. Therefore, the present work studies the mandrel dynamics and their effect on the tubular structural response. A mathematical model, which is an extension of the quasistatic tubular expansion analysis, has been developed to describe the dynamic friction effects of the Stick-Slip Phenomenon. A special case of tubular expansion consisting of 25% expansion ratio of a 4/12 in. liner hanger was considered. It was found that the level of mandrel oscillations is in the order of 1–2 mm around its equilibrium position resulting in tubular thickness reduction of approximately 9% on top of its variation caused by the steady state expansion process. This increase in thickness reduction may affect the postexpansion collapse strength of the tubular. DOI: 10.1115/1.3066412