Challenging ICD & Swell Packers Completion Running in 3D Complex ERD Well With Continuous Swiveling to Break Frictional Drag and Helical Buckling

2018 ◽  
Author(s):  
Rudra Pratap Narayan Singh ◽  
Phalgun Paila ◽  
Rashid Khudaim Al-Kindi ◽  
Khalid Ahmed Al-Wahedi ◽  
Cliff Kirby ◽  
...  
Keyword(s):  
Frictional Drag ◽  
Helical Buckling

Helical Buckling of Pipes in Extended Reach and Horizontal Wells—Part 2: Frictional Drag Analysis

1993 ◽  
Vol 115 (3) ◽  
pp. 196-201 ◽  
Author(s):  
J. Wu ◽  
H. C. Juvkam-Wold
Keyword(s):  
Differential Equation ◽  
Analytical Solution ◽  
Laboratory Experiments ◽  
Horizontal Wells ◽  
Force Balance ◽  
Axial Loads ◽  
Frictional Drag ◽  
Well Completion ◽  
Helical Buckling ◽  
Drag Analysis

This paper studies the frictional drag of helically buckled pipes (drillstring and tubing) in extended reach and horizontal wells to correctly predict the actual bit weight or packer load, in cases where helical buckling of pipes may have occurred. Helical buckling of pipes in such wells may occur, since large axial loads are often required. The differential equation of axial force balance with consideration of the axial friction for helically buckled pipes is resolved, and the solution shows that when the pipes are helically buckled, the frictional drag will become very large. The actual bit weight for drilling or packer load for well completion may therefore become much smaller than estimated under the unbuckled pipe conditions. The analytical solution is also shown to agree with the results from laboratory experiments, which simulate the real wellbore-pipe conditions. An example is provided to show the calculation procedure and the importance of the results.

Buckling and Lockup of Tubulars in Inclined Wellbores

1995 ◽  
Vol 117 (3) ◽  
pp. 208-213 ◽  
Author(s):  
J. Wu ◽  
H. C. Juvkam-Wold
Keyword(s):  
Contact Force ◽  
Inclination Angle ◽  
Compressive Load ◽  
Buckling Load ◽  
Entire Length ◽  
Frictional Drag ◽  
Axial Compressive Load ◽  
Helical Buckling

This paper studies sinusoidal and helical buckling of tubulars in inclined wellbores and the “lockup” of tubulars due to buckling. The results show that tubular buckling starts from the tubular bottom in low-inclination wellbores, where the axial compressive load is largest due to tubular weight. In high-inclination wellbores it may start from the top portion of the tubular, where the axial compressive load is largest due to frictional drag. This clarifies the confusion on whether or not the tubular buckles at once on its entire length in inclined wellbores. New sinusoidal and helical buckling load equations are presented to better predict tubular buckling in inclined wellbores (0–90 deg). The lower the wellbore inclination angle, the smaller the axial compressive load required to initiate tubular buckling. However, a certain nonzero axial compressive load is still needed to buckle the tubulars in vertical wellbores. When tubulars buckle helically, a large wall contact force will be generated, and the “slack-off” weight at the surface will not be fully transmitted to the tubular bottom due to large resultant frictional drag. The “lockup” of tubulars may even occur, where the tubular bottom load cannot be increased by slacking-off weight at the surface.

The Surface-Roughness of Bearing-Surfaces and its Relation to Oil Film Thickness at Breakdown

1949 ◽  
Vol 161 (1) ◽  
pp. 73-79 ◽  
Author(s):  
A. Cameron
Keyword(s):  
Surface Roughness ◽  
Film Thickness ◽  
Hydrodynamic Theory ◽  
Quantitative Relation ◽  
Metal Contact ◽  
Initial Contact ◽  
Frictional Drag ◽  
Average Roughness ◽  
Finished Steel ◽  
Oil Film

In this paper the relation of surface roughness of bearing surfaces to allowable film thickness is studied quantitatively with a simple Michell pad apparatus. The pads used were faced with white metal and ran against mild steel collars. The lubricants studied were water, soap solution, paraffin, and light oil. There was little difference in the frictional behaviour of any of the lubricants, except that the aqueous lubricants would not run with very finely finished steel surfaces. The onset of metal to metal contact was detected by an increase in the frictional drag, and also by the change in electrical conductivity between the pad and collar—an extremely sensitive method. The paper shows that there is, at any rate for this system, a quantitative relation between the total surface roughness of the rubbing surfaces and the calculated oil film thickness both at the initial metal to metal contact and seizure. Initial contact occurs when the outlet film thickness, calculated from normal hydrodynamic theory, falls to three times the maximum surface roughness and seizure occurs when it is double the average roughness.

Note on the swimming of slender fish

1960 ◽  
Vol 9 (2) ◽  
pp. 305-317 ◽  
Author(s):  
M. J. Lighthill
Keyword(s):  
Swimming Speed ◽  
Critical Value ◽  
Slender Body ◽  
Vortex Wake ◽  
Frictional Drag ◽  
Slender Body Theory ◽  
Propulsive Efficiency ◽  
Deformable Bodies ◽  
Work Done ◽  
Body Theory

The paper seeks to determine what transverse oscillatory movements a slender fish can make which will give it a high Froude propulsive efficiency, $\frac{\hbox{(forward velocity)} \times \hbox{(thrust available to overcome frictional drag)}} {\hbox {(work done to produce both thrust and vortex wake)}}.$ The recommended procedure is for the fish to pass a wave down its body at a speed of around $\frac {5} {4}$ of the desired swimming speed, the amplitude increasing from zero over the front portion to a maximum at the tail, whose span should exceed a certain critical value, and the waveform including both a positive and a negative phase so that angular recoil is minimized. The Appendix gives a review of slender-body theory for deformable bodies.

Mechanism of the Transition From In-Plane Buckling to Helical Buckling for a Stiff Nanowire on an Elastomeric Substrate

2016 ◽  
Vol 83 (4) ◽  
Author(s):  
Youlong Chen ◽  
Yong Zhu ◽  
Xi Chen ◽  
Yilun Liu
Keyword(s):  
High Performance ◽  
Three Dimensional ◽  
Stretchable Electronics ◽  
Buckling Mode ◽  
Design And Optimization ◽  
Out Of Plane ◽  
Plane Direction ◽  
Plane Displacement ◽  
Helical Buckling ◽  
Selection Of

In this work, the compressive buckling of a nanowire partially bonded to an elastomeric substrate is studied via finite-element method (FEM) simulations and experiments. The buckling profile of the nanowire can be divided into three regimes, i.e., the in-plane buckling, the disordered buckling in the out-of-plane direction, and the helical buckling, depending on the constraint density between the nanowire and the substrate. The selection of the buckling mode depends on the ratio d/h, where d is the distance between adjacent constraint points and h is the helical buckling spacing of a perfectly bonded nanowire. For d/h > 0.5, buckling is in-plane with wavelength λ = 2d. For 0.27 < d/h < 0.5, buckling is disordered with irregular out-of-plane displacement. While, for d/h < 0.27, buckling is helical and the buckling spacing gradually approaches to the theoretical value of a perfectly bonded nanowire. Generally, the in-plane buckling induces smaller strain in the nanowire, but consumes the largest space. Whereas the helical mode induces moderate strain in the nanowire, but takes the smallest space. The study may shed useful insights on the design and optimization of high-performance stretchable electronics and three-dimensional complex nanostructures.

Helical Buckling of Pipe with Connectors and Torque

2004 ◽  
Author(s):  
Robert F. Mitchell ◽  
Stefan Miska
Keyword(s):  
Helical Buckling

Experimental Performance of a Trochoidal Propeller with High-Aspect-Ratio Blades

1989 ◽  
Vol 26 (03) ◽  
pp. 192-201 ◽  
Author(s):  
Neil Bose ◽  
Peter S. K. Lai
Keyword(s):  
Aspect Ratio ◽  
High Efficiency ◽  
Open Water ◽  
Finite Amplitude ◽  
Dynamic Stall ◽  
Frictional Drag ◽  
Overall Performance ◽  
Small Ship ◽  
Propeller Performance ◽  
Thrust And Torque

Open-water experiments were done on a model of a cycloidal-type propeller with a trochoidal blade motion. This propeller had three blades with an aspect ratio of 10. These experiments included the measurement of thrust and torque of the propeller over a range of advance ratios. Tests were done for forward and reverse operation, and at zero speed (the bollard pull condition). Results from these tests are presented and compared with: a multiple stream-tube theoretical prediction of the performance of the propeller; and a prediction of the performance of a single blade of the propeller, oscillating in heave and pitch, using unsteady small-amplitude hydrofoil theory with corrections for finite amplitude motion, finite span, and frictional drag. At present, neither of these theories gives a completely accurate prediction of propeller performance over the whole range of advance ratios, but a combination of these approaches, with an allowance for dynamic stall of the blades, should lead to a reliable simple theory for overall performance prediction. Application of a propeller of this type to a small ship is discussed. The aim of the design is to produce a lightly loaded propeller with a high efficiency of propulsion.

Permeability of Human Glenohumeral Joint Cartilage

1999 ◽  
Author(s):  
Anna Stankiewicz ◽  
Gerard A. Ateshian ◽  
Louis U. Bigliani ◽  
Van C. Mow
Keyword(s):  
Mechanical Properties ◽  
Articular Cartilage ◽  
Interstitial Fluid ◽  
Glenohumeral Joint ◽  
Solid Matrix ◽  
Joint Cartilage ◽  
Frictional Drag ◽  
Diarthrodial Joints ◽  
Flow Through ◽  
Fluid Pressurization

Abstract The nearly frictionless lubrication in diarthrodial joints and load support within articular cartilage depends on its mechanical properties. It has been shown that the majority of applied loads on cartilage are supported by interstitial fluid pressurization (Ateshian et al., 1994) which results from the frictional drag of flow through the porous permeable solid matrix. The duration and magnitude of this pressurization are a function of the permeability of cartilage (Lai et al., 1981).

Jointed Tubing Injector Snubbing on Extended Reach Wells

2021 ◽  
Author(s):  
H. J. Miller ◽  
A. D. Richard
Keyword(s):  
Control System ◽  
Static Friction ◽  
Block System ◽  
Coiled Tubing ◽  
Continuous Movement ◽  
Safety Risks ◽  
Helical Buckling ◽  
And Control

Abstract OBJECTIVE / SCOPE An injector has been developed that is able to continuously move conventional jointed tubing in and out of wells that may be underbalanced. It is an advantage to use the jointed tubing injector rather than coiled tubing or conventional hydraulic snubbing due to cost, speed of operation, transportation, effectiveness, and safety. The paper will describe the function and application of the jointed pipe injector. METHODS, PROCEDURES, PROCESS An injector has been designed with retractable gripping segments integral to the gripper blocks that are able to function on conventional jointed tubing, over interconnecting couplings and with the advantages of continuously operating injector movement. The description is to include how the geometry of the retractable gripper block system works and how the technical and safety risks of a conventional snubbing system or coiled tubing are overcome. Configurations whereby the jointed tubing injector can be used to provide methods of completing wells that are safer and more efficient than coiled tubing or a conventional hydraulic snubbing jack will be presented. RESULTS, OBSERVATIONS, CONCLUSIONS The biggest limitation of coiled tubing is due to its size and residual bend, it is not capable of reaching the end of the well before the wellbore friction causes helical buckling. The OD of the coiled tubing is limited by the available reel sizes and the difficulty transporting the large reels due to road dimensional and weight limitations. Coiled tubing is not able to be rotated at any time in the well. The use of jointed tubing eliminates those limitations. When a well is being completed with a conventional hydraulic snubbing jack, the length of the stroke that the jack can take is limited by the allowable unsupported length of the tubing to ensure that it will not buckle. It is also forced to stop workstring movement each time the jack is reset therefore the static friction of the workstring must be overcome during each movement of the jacks. The design of the jointed tubing injector minimizes the unsupported length of the tubing and allows the continuous movement of the tubing. The operation is less labor intensive, and the controls can be moved to a position that is less exposed to danger. NOVEL / ADDITIVE INFORMATION The Jointed Tubing Injector can continuously move jointed tubulars in and out of a well. There is no other piece of equipment that will address as many of the problems that have been experienced in the completion of extended reach wells. The paper will describe the injector and control system and how it can be applied to solve the challenges.

scholarly journals Tabular Icebergs: Implication from Geophysical Studies of Ice Shelves

1980 ◽  
Vol 1 ◽  
pp. 55-55
Author(s):  
Sion Shabtaie ◽  
Charles R. Bentley
Keyword(s):  
Mass Balance ◽  
Sea Water ◽  
Ice Thickness ◽  
Ice Shelf ◽  
Frictional Drag ◽  
Ice Shelves ◽  
Ross Ice Shelf ◽  
Rift Zones ◽  
Different Characteristics ◽  
Ice Water

Recent geophysical and glaciological investigations of the Ross Ice Shelf have revealed many complexities in the ice shelf that can be important factors in iceberg structure. The presence of rift zones, surface and bottom crevasses, corrugations, ridges and troughs, and other features could substantially modify the hydraulics of iceberg towing and lead to disintegration of the berg in the course of transport.The relationships between the elevation above sea-level and total ice thickness for three ice shelves (Ross, Brunt, and McMurdo) are given; from them, expressions for the thickness/freeboard ratios of tabular icebergs calved from these ice shelves are obtained. The relationships obtained from the measured values of surface elevation and ice thickness are in agreement with models derived assuming hydrostatic equilibrium.Areas of brine infiltration into the Ross Ice Shelf have been mapped. Examples of radar profiles in these zones are shown. Absorption from the brine layers results in a poor or absent bottom echo. It is probable that little saline ice exists at the bottom of the Ross Ice Shelf front due to a rapid bottom melting near the ice front, and that the thickness of the saline ice at the bottom of icebergs calving from the Ross Ice Shelf is no more than a few meters, if there is any at all.We have observed many rift zones on the ice shelf by airborne radar techniques, and at one site the bottom and surface topographies of (buried) rift zones have been delineated. These rift zones play an obvious role in iceberg formation and may also affect the dynamics of iceberg transport. Bottom crevasses with different shapes, sizes, and spacings are abundant in ice shelves; probably some are filled with saline ice and others with unfrozen sea-water. Existence of these bottom crevasses could lead to a rapid disintegration of icebergs in the course of transport, as well as increasing the frictional drag at the ice-water boundary.Radar profiles of the ice-shelf barrier at four sites in flow bands of very different characteristics are shown. In some places rifting upstream from the barrier shows regular spacings, suggesting a periodic calving. Differential bottom melting near the barrier causes the icebergs to have an uneven surface and bottom (i.e. dome-shaped).Electrical resistivity soundings on the ice shelf can be applied to estimate the temperature-depth function, and from that the basal mass-balance rate. With some modifications, the technique may also be applied to estimating the basal mass-balance rates of tabular icebergs.

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