Project 8: Determine the Effect of Various Slot Geometries
Data Analysis
5000 4500 4000 0.022
Background
Objective • Create pipe geometries using CAD and analyze using finite element analysis (FEA) methods. • Create custom non-linear materials and implement appropriate constraints during FEA modeling to achieve desired results. `
Results
*All results are shown from interior pressure
Slot Depth Effects
18000
Failure Pressure (psi)
Baker Hughes utilizes a variety of pipe configurations to retrieve oil and gas. One of these methods involves cutting slots into the outer diameter of the pipe that can be used as anchor points. The slots’ affect on the failure pressure must be known to ensure that the pipe will not burst or collapse during operation.
0.024
16000
Super 13 Chrome
14000
4140 Steel
12000
825 Nickel
6000 4000 2000 0 0.16
0.18
0.2
0.22
0.24
0.26
Slot Depth (in) Internal and External Pressure
14000 12000 10000 8000 6000
Super 13 Chrome
4000
4140 Steel
2000
825 Nickel
0 1.14
2.14
3.14
4.14
5.14
Slot Length (in) Slot Length
Slot Width
Slot Depth
Super 13 Chrome
4000
4140 Steel
2000
825 Nickel
0 0
0.1
0.2
0.3
0.4
Slot Width (in)
0.5
• Similar to slot length, the increase in slot width beyond 0.4 inches showed minimal effect on the failure pressure.
Concentric
10000
Non-Concentric
9500 9000 8500 8000 2
4
6
8
• From 1 to 4 slots, the failure pressures are highly variable due to the inconsistency with which the slots align with the thinner portions of the nonconcentric material of the pipe. As the slot number increases beyond 4, the slot alignment with the material becomes more consistent and the failure tends to remain uniform.
16000
0.14
6000
Number of Slots
18000
• Use the data obtained from FEA to locate and analyze trends in slot dimensions and failure pressures for implementation during their pipe design process at Baker Hughes. The effect of the number, length, width and depth of slots on 4140 Steel, 825 Nickel and Super 13 Chrome pipes will be analyzed and trends in the effects will be identified.
8000
0
Slot Length Effects Failure Pressure (psi)
Fixed Support
10000
7500
• Increase in slot depth caused the failure pressure to decrease consistently throughout each material. Deformation Probes
12000
10500
8000
0.14
14000
Number of Slot Effects
10000
Displacement Constraint
16000
Failure Pressure (psi)
5500
18000
Failure Pressure (psi)
Advisor: Dr. Haider Hekiri
Pressure (psi)
6000
Team: Mario Perez, Garrett Gore, Ethan Bean, & John Haley Corporate Liaison: Greg Narro
• Failure pressure was determined by the intersection of a 0.0002 inch offset line and the deformation of the pipe as pressure increases. For 825 Nickel 1 Slot Pipe example, for 825 Nickel 1 Offset Slot Pipe the failure 0.026 0.028 0.030 0.032 pressure occurred at approximately 5100 psi. Deformation (in)
Failure Pressure Location
Slot Width Effects
• Initial increase in slot length showed decreases in failure pressure. As the slot length increased beyond 2 inches, the effects were negligible.
Conclusion
There are a number of characteristics of slots within pipes used to retrieve oil and gas that can affect the pipe’s ability to withstand pressure. Based on FEA results, slot depth appeared to have the greatest, most consistent effect, while slot length and width show a smaller effect that is negligible beyond a certain point. The number of slots was more variable in it’s effect, when the slot number is less than four.