4.3 SIMULATION OF STATIC CHARACTERISTICS OF THE TUBING FOR
4.3.2 DEFORMATION AND STRESS OCCURRING ON THE TUBING FOR
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Figure 4.17: The Graph of Difference of Pressure Exerted on Tubing at Different Production Rates
4.3.2 DEFORMATION AND STRESS OCCURRING ON THE TUBING FOR
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Figure 4.18: Von-Mises Stress Occurring on the Tubing for Production Rate=5000bbl/day at the Packer Region
Figure 4.19: Shear Stress Occurring on the Tubing for Production Rate=5000bbl/day at the Packer Region
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Figure 4.20: Principal Stress Occurring on the Tubing for Production Rate=5000bbl/day at the Packer Region
Figure 4.21: Deformation Occurring on the Tubing for Production Rate=5000bbl/day at the Inlet Region
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After that, for the simulation of Ansys Static Structural for production rate of 5500bbl/day, the Von-Mises stress, shear stress, principal stress and deformation occurring on the tubing for production rate of 5500bbl/day ( as shown in Fig. 4.22, 4.23, 4.24 and 4.25 below) are obtained.
Figure 4.22: Von-Mises Stress Occurring on the Tubing for Production Rate=5500bbl/day at the packer region
Figure 4.23: Shear Stress Occurring on the Tubing for Production Rate=5500bbl/day at the packer region
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Figure 4.24: Principal Stress Occurring on the Tubing for Production Rate=5500bbl/day at the packer region
Figure 4.25: Deformation Occurring on the Tubing for Production Rate=5500bbl/day at the Inlet Region
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After that, for the simulation of Ansys Static Structural for production rate of 6000bbl/day, the Von-Mises stress, shear stress, principal stress and deformation occurring on the tubing for production rate of 6000bbl/day ( as shown in Fig. 4.26, 4.27, 4.28 and 4.29 below) are obtained.
Figure 4.26: Von-Mises Stress Occurring on the Tubing for Production Rate=6000bbl/day at the Packer Region
Figure 4.27: Shear Stress Occurring on the Tubing for Production Rate=6000bbl/day at the Packer Region
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Figure 4.28: Principal Stress Occurring on the Tubing for Production Rate=6000bbl/day at the Packer Region
Figure 4.29: Deformation Occurring on the Tubing for Production Rate=6000bbl/day at the Inlet region
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After that, for the simulation of Ansys Static Structural for production rate of 6500bbl/day, the Von-Mises stress, shear stress, principal stress and deformation occurring on the tubing for production rate of 6500bbl/day ( as shown in Fig. 4.30, 4.31, 4.32 and 4.33 below) are obtained.
Figure 4.30: Von-Mises Stress Occurring on the Tubing for Production Rate=6500bbl/day at the packer region
Figure 4.31: Shear Stress Occurring on the Tubing for Production Rate=6500bbl/day at the packer region
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Figure 4.32: Principal Stress Occurring on the Tubing for Production Rate=6500bbl/day at the packer region
Figure 4.33: Deformation Occurring on the Tubing for Production Rate=6500bbl/day at the Inlet region
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Then, using values in Fig. 4.18, 4.19, 4.20, 4.22, 4.23, 4.24, 4.26, 4.27, 4.28, 4.30, 4.31 and 4.32, the Table 4.3 is constructed. Table 4.3, as shown below is showing the maximum Von-Mises stress, maximum shear stress and maximum principal stress occurring on the tubing at production rates of 5000, 5500, 6000 and 6500bbl/day.
Table 4.3: The Stress Occurring on the Tubing at Different Production Rates Production
Rate (bbl/day)
Maximum Von-Mises Stress (E+5 Pa)
Maximum Shear Stress (E+5 Pa)
Maximum Principal Stress (E+5 Pa)
5000 8.203 4.7242 8.3183
5500 8.9285 5.1181 8.9824
6000 9.7785 5.6062 9.7428
6500 10.672 6.1193 10.546
After that, from values in Table 4.3, the Fig. 4.34 (as shown below) is plotted, showing the stress occurring on the tubing at production rates of 5000, 5500, 6000 and 6500bbl/day. From Fig. 4.34, it can be seen that, the higher the production rate, the higher the shear stress occurring on the tubing, the higher the principal stress occurring on the tubing, the higher the Von-Mises stress occurring on the tubing. For Von-Mises stress, the maximum stress is 10.672 E+5 Pa at 6500 bbl/day, while maximum shear stress is 6.1193E+5 Pa at 6500bbl/day, and the maximum principal stress is 10.546E+5 Pa at 6500bbl/day. The stress occurring on the tubing increases as the production rate increases. This is because the pressure exerted onto the tubing affects the stress and deformation. As the production rate increases, the pressure exerted onto the tubing also increases, which creates higher fluid loading as the production rate increases, resulting in higher stress. Therefore, as production rate increases, stress exerted onto the tubing increases.
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Figure 4.34: The Graph of Maximum Stress on the Tubing vs Production Rate Then, using values in Fig. 4.21, 4.25, 4.29 and 4.33, the Table 4.4 is constructed. Table 4.4, as shown below is showing the maximum deformation occurring on the tubing at production rates of 5000, 5500, 6000 and 6500bbl/day.
Table 4.4: The Deformation Occurring on the Tubing at Different Production Rates Production Rate (bbl/day) Maximum Deformation (E-5 m)
5000 2.8619
5500 3.0975
6000 3.3668
6500 3.651
After that, from values in Table 4.4, the Fig. 4.35 (as shown below) is plotted, showing the maximum deformation occurring on the tubing at production rates of 5000, 5500, 6000 and 6500bbl/day. From Fig. 4.35, it can be seen that, the maximum deformation is 3.651E-5m at 6500bbl/day, while the minimum deformation is 2.8619E-5m at 5000bbl/day. Thus, the higher the production rate, the higher the deformation occurring on the tubing. The deformation occurring on the tubing increases as the production rate increases because the pressure and stress exerted onto the tubing affects the deformation.
As the production rate increases, the pressure exerted onto the tubing also increases, 4
5 6 7 8 9 10 11
4500 5000 5500 6000 6500 7000
Maximum Stress (E+5 Pa)
Production Rate (bbl/day)
Graph of Stress Vs Production Rate
Shear Stress Principal Stress Von-Mises Stress
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which creates higher fluid loading as the production rate increases, resulting in higher stress. Therefore, this increase in stress is causing the increase in deformation.
Therefore, as production rate increases, deformation exerted onto the tubing increases.
Figure 4.35: The Graph of Maximum Deformation vs Production Rate
However, as to whether the tubing experienced permanent or elastic deformation, it depends on the yield strength of the tubing. When the stress occurring on the tubing exceeds yield strength of the tubing, the tubing will experience permanent deformation, whereby the tubing will not return to original configuration even after the loading is released. On the other hands, when the stress occurring on the tubing is less than the yield strength of the tubing, the tubing experience elastic deformation, whereby the tubing will return to original configuration after the loading is released. Von-Mises stress is the stress which is usually applied for ductile material, and since the L80 steel is ductile material with yield strength of 80000psi or 5.5158E+8 Pa, Von-Mises stresses are compared with the yield strength to determine the type of deformation. The maximum stress exerted onto the tubing is 10.672E+5 Pa, which is less than the yield strength of the tubing, which is 5.5158E+8 Pa. Therefore, for the production rates of 5000, 5500, 6000 and 6500bbl/day, the tubing only experience elastic deformation.
0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5
4500 5000 5500 6000 6500 7000
Maximum Deformation (E-5 m)
Production Rate (bbl/day)
Graph of Maximum Total Deformation Vs Production Rate
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4.4 SIMULATION OF DYNAMIC CHARACTERISTICS OF THE TUBING