An Improved Analysis of Axial Force Along Coiled Tubing in Inclined/Horizontal Wellbores

1996 ◽  
Author(s):  
Stefan Miska ◽  
Weiyong Qiu ◽  
Len Volk ◽  
J.C. Cunha
Keyword(s):  
Axial Force ◽  
Coiled Tubing ◽  
Horizontal Wellbores

Experimental Study on the Mechanics of a Coiled Tubing Working Within a Marine Riser Under the Affection of Marine Loads

2019 ◽  
Author(s):  
Yingchun Chen ◽  
Chang Wang ◽  
Xinhua Wang ◽  
Wenming Wang ◽  
Wenda Wang
Keyword(s):  
Axial Force ◽  
Oil And Gas ◽  
Excitation Frequency ◽  
Experimental System ◽  
Transfer Efficiency ◽  
Force Transmission ◽  
Marine Riser ◽  
External Excitation ◽  
Pipe System ◽  
Coiled Tubing

Abstract Due to its unique advantages, coiled tubing is now widely used in marine oil and gas exploitation operations, while the mechanical behavior of coiled tubing working within a marine riser affected by marine loads is still unknown. By building an indoor simulation experimental system, the mechanics of this pipe-in-pipe system was studied, and the effect of the lateral excitation on the axial force transmission of inner pipe was clarified. It was found that, when the external excitation frequency was within the first natural frequency range of the outer pipe, the external excitation would increase the axial load transfer efficiency of the inner pipe, and the axial force transfer efficiency of the inner tube would reach the maximum when the resonance of out pipe occurred. The results can be helpful on the understanding of mechanics of a coiled tubing working within a marine riser.

The Mechanical Analysis of the Coiled Tubing

2013 ◽  
Vol 385-386 ◽  
pp. 154-158
Author(s):  
Ju Bao Liu ◽  
Chun Sheng He ◽  
Qian Bei Yue
Keyword(s):  
Axial Force ◽  
Mechanical Analysis ◽  
Actual State ◽  
Contact State ◽  
Coiled Tubing ◽  
Mechanical Models

With respect to the conventional coupling thread, the coiled tubing had the advantages of without screwing on and screwing off in the lifting pipe string. It was widespread used in the drilling and repairing well. According to the actual state of the coiled tubing, the mechanical models on the ground and in the wellbore were established in this article. The were able to simulate the contact state of the coiled tubing through the drum, the guide frame, the injector head and in the wellbore. The curves of the axial force that through the rollers, guide frame, injection head and wellhead was obtained with the changes of the depth.

The helical buckling and extended reach limit of coiled tubing with initial bending curvature in horizontal wellbores

2021 ◽  
Vol 200 ◽  
pp. 108398
Author(s):  
Jiantao Zhang ◽  
Guofu Yin ◽  
Yu Fan ◽  
Huali Zhang ◽  
Lu Tian ◽  
...  
Keyword(s):  
Coiled Tubing ◽  
Helical Buckling ◽  
Horizontal Wellbores

Strength Analysis of Coiled Tubing in the Injector

2010 ◽  
Vol 97-101 ◽  
pp. 2720-2723 ◽  
Author(s):  
Zheng Liang ◽  
Huai Xin Mao ◽  
Guang Hui Zhao ◽  
Fa Guang Jiang
Keyword(s):  
Stress State ◽  
Axial Force ◽  
Yield Criterion ◽  
Strength Analysis ◽  
Yield Limit ◽  
Coiled Tubing ◽  
Inner Pressure ◽  
Gripping Force ◽  
Force Pressure ◽  
Sinusoidal Function

Coiled tubing (CT) injector head is a key part of CT unit. Friction between gripper blocks and CT offers axial force that runs and retrieves the CT into or out of the wellbore. The CT held by the gripper blocks is loaded by axial force, pressure of inner fluid and gripping force, and is in a complex forcing state. Here it was assumed that all stresses were invariable longitudinally and could be simplified as problem of plane strain. The gripping force acted on the outer surface of CT was set as sinusoidal function along circumference. Stress function was employed to deduce the stress state of CT in gripper blocks. The effects of gripping force, inner pressure and axial force on CT strength were studied, and yield limit curves of the CT were presented by Mises yield criterion. These results offer referring data for minimizes the risk of scarring or mashing the CT.

Dynamic Analysis on Unbuckling Process of Helically Buckled Coiled Tubing While Milling Plugs

2018 ◽  
Vol 140 (9) ◽  
Author(s):  
Xing Qin ◽  
Deli Gao ◽  
Yongsheng Liu
Keyword(s):  
Contact Force ◽  
Axial Force ◽  
Compressive Force ◽  
Axial Compressive Force ◽  
Continuous Contact ◽  
Well Completion ◽  
Coiled Tubing ◽  
Milling Operations ◽  
Helical Angle ◽  
Calculation Results

In down-hole interventions, the thin elastic coiled tubing (CT) extended for thousands of meters underground would typically undergo helical buckling as a result of axial compressive force. This paper builds an analytical model to describe the unbuckling behavior of a helically buckled CT with a new view to the stretching process in the plug milling operations. The new dynamic unbuckling equation is built on the basis of the general bending and twisting theory of rods. Under the continuous contact assumption, the helical angle is only subject to time; thus, the dynamic equations can be simplified and the analytical solutions can be obtained. By using the new governing equations, the angular velocity, axial force, and contact force relative to CT are analyzed in the unbuckling process. The calculation results indicate that the parameters including CT diameters and wellbore diameters have a strong influence on the variation of axial force and wellbore contact force. Moreover, the wellbore contact force is greater than zero during the whole unbuckling process which confirms the continuous contact assumption. These new results provide important guidance for accurate job design for the plug milling operations during the well completion stage.

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