Numerical Study of Oil Storage Tanks during Planar Settlement

2018 ◽  
Vol 878 ◽  
pp. 95-103
Author(s):  
Joko Wisnugroho ◽  
Sutomo
Keyword(s):  
Finite Element ◽  
Storage Tank ◽  
Numerical Study ◽  
Plate Thickness ◽  
Element Model ◽  
American Petroleum Institute ◽  
Seismic Zone ◽  
Storage Tanks ◽  
Oil Storage ◽  
Oil Storage Tank

Inspection and maintenance are necessary to maintain the continuity of critical equipment operations such as oil storage tank. The criteria for the various types of settlement specified in American Petroleum Institute (API) 653. However, the criteria for planar settlement could not be determined. In this paper, a finite element model is developed to study the hoop stress of the tank during planar settlement. In this paper, 384 finite element models were built in order to predict the most effective allowable planar settlement at oil storage tanks. Each model is variation of the tank size, shell plate thickness, seismic zone and planar tilt of the tank. Based on size of tank population in Pertamina, 8 of standard tank size from 500-10.000 m3 were simulated. The simulation results are validated by case study in 500-5.000 m3 full scale oil storage tank. From the results, equation for criteria of planar settlement has been created.

Oil Storage Tank Settlement Assessment Based on Standard and Finite Element Analyses

2017 ◽  
Author(s):  
Lei Shi ◽  
Xiaolin Wang ◽  
Jian Shuai ◽  
Kui Xu ◽  
Ming Li
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Storage Tank ◽  
Large Scale ◽  
Element Model ◽  
Foundation Settlement ◽  
Storage Tanks ◽  
Strength Assessment ◽  
Oil Storage ◽  
Oil Storage Tank

It is well known that foundation settlement of tank is particularly severe, and can produce distortion and stress of the tank, especially differential settlement around the circumference of the foundation below the shell of large-volume tank. The settlement standards involving European EEMUA 159-2003, American API 653-2009, and Chinese codes SH/T 3123-2001, SY/T 5921-2011 for in-service assessment of large-scale storage tank were reviewed and discussed. Finite element model for strength assessment of large-scale oil storage tank was developed based on actual field data of tank foundation settlement. The whole stress distributions and deformation of seven large-scale oil storage tanks in a depot in China were analyzed under the conditions of the practical pressure test through finite-element method. It also provides a comparison between an analytical model based on settlement criteria and a finite element model that replicates field operating loading and settlement conditions of storage tanks. A basis for comparison between models was established from the maximum allowable settlement and stress values. It was found that results from settlement standards of tank in China and other countries were more conservative than those from FEA, and SY/T 5921 in China made most stringent requirements for the tank settlement. The evaluation indicators of differential foundation settlement around the tank circumference are unreasonable in standards and rules mentioned above, the structural response of tank such as stress and deformation under foundation settlement should be considered sufficiently.

Elephant Foot Buckling Analysis of Large Unanchored Oil Storage Tanks With Tapered Shells Subjected to Foundation Settlement

2020 ◽  
Author(s):  
Lei Shi ◽  
Xiaolin Wang ◽  
Liang Chang ◽  
Xue Li
Keyword(s):  
Finite Element ◽  
Numerical Study ◽  
Plastic Material ◽  
Element Model ◽  
Nonlinear Boundary Conditions ◽  
Storage Tanks ◽  
Nonlinear Stabilization ◽  
Buckling Strength ◽  
Oil Storage ◽  
Steel Tank

Abstract This paper presents an numerical study on a large unanchored open-topped steel tank. The buckling behaviors of the tank are analyzed using the finite element computer package ANSYS by means of nonlinear stabilization algorithm. The effects of foundation harmonic settlement on the elephant foot buckling strength of large unanchored open-topped oil storage tanks with tapered shells under axial compression are explored by numerical modeling. Various items of actual geometrical structure which involve concrete ringwall foundation of tank, unanchored bottom with slope, shell tapering from the base to the top, wind girders and supports, top angles, stiffening rings and support plates are presented thoroughly in the non-symmetrical 3D finite element model. Geometric nonlinearity, nonlinear boundary conditions and elastic plastic material of Ramberg-Osgood model are involved simultaneously in simulate course. The obtained solutions are displayed graphically for selected values of system parameters: harmonic settlement amplitude, harmonic number, and critical buckling stress of axially compressed oil tank. The results will provide insights into the relationship between foundation harmonic settlement and buckling strength of the large cylinders.

Deformation Characteristic Evaluation of Large Oil Storage Tanks under the Planar Inclined Foundation

2013 ◽  
Vol 351-352 ◽  
pp. 786-789
Author(s):  
Da Wei Ji ◽  
Li Xin Wei ◽  
Xiao Yan Li
Keyword(s):  
Stress Distribution ◽  
Storage Tank ◽  
Large Scale ◽  
Deformation Characteristic ◽  
Oil Industry ◽  
Element Model ◽  
Storage Tanks ◽  
Oil Storage ◽  
Oil Storage Tank ◽  
The Finite Element Model

Oil storage tank plays an important role in modern oil industry. The development of large-scale oil storage tanks has resulted in the complexity of stress distribution and deformation situation of tank wall and tank bottom. Especially in soft foundations, the tank structure is susceptible to various types of settlement deflections. The most common type is planar inclined foundation. In this paper, the finite element model of large-scale oil storage tank was built according to the pattern of design and the deformation characteristic and stress distribution of large storage tank under the planar inclined foundation was obtained. Considering the floating roof, the ultimate value of large storage tank under the planar inclined foundation is determined.

Tsunami Damage to Oil Storage Tanks in the MW9.0 2011 Tohoku, Japan Earthquake

2015 ◽  
Author(s):  
Ken Hatayama
Keyword(s):  
Storage Tank ◽  
Prediction Method ◽  
Tohoku Earthquake ◽  
Storage Tanks ◽  
The 2011 Tohoku Earthquake ◽  
Inundation Depth ◽  
Oil Storage ◽  
Tsunami Damage ◽  
Oil Storage Tank ◽  
Actual Damage

The Mw9.0 2011 Tohoku, Japan earthquake tsunami damaged 418 oil storage tanks located along the Pacific coast of the Hokkaido, Tohoku, and Kanto Districts of Japan. A wide variety of damage was observed, including movement and deformation of the tank body, scouring of the tank base and ground, and movement or structural fracture of the pipe. In total, 157 of the 418 tanks were moved by the tsunami. By comparing the severity of damage with the inundation depth of the tsunami experienced by the oil storage tank, a fragility curve projecting the damage rate for plumbing is presented, and a rough but easy-to-use method of predicting tsunami damage to an oil storage tank from a given inundation depth is also presented: (i) for inundation depths of 2–5 m, tanks suffer damage to their plumbing, and small tanks (capacity < 100 m3) and empty larger tanks may be moved; (ii) for inundation depths of greater than 5 m, most tanks are moved. The validity of the previously-proposed tsunami tank-movement prediction method is first examined. A comparison of the method’s predictions with the actual damage data from the 2011 Tohoku earthquake tsunami indicates a high hit rate of 76%.

Optimization Calculation Method of Wall Thickness for Large Oil Storage Tank Made of High Strength Steel

2015 ◽  
Author(s):  
Haigui Fan ◽  
Zhiping Chen ◽  
Futeng Wan
Keyword(s):  
Wall Thickness ◽  
High Strength Steel ◽  
Storage Tank ◽  
Circumferential Stress ◽  
High Strength ◽  
Optimization Method ◽  
Storage Tanks ◽  
Oil Storage ◽  
Optimization Calculation ◽  
Oil Storage Tank

Optimization calculation method determining wall thickness for large oil storage tank made of high strength steel is investigated in this paper. Taking three oil storage tanks with different volumes of 10×104 m3, 15×104 m3 and 20×104 m3 for examples, the wall thickness calculation methods of API 650, GB 50341, JIS B 8501 and BS EN 14015 have been analyzed and compared. Results show that as the volume of oil storage tank increases, some wall thickness calculation results of the standards have been larger than the allowable value, leading to the unreasonable distribution of the wall circumferential stress. The wall thickness calculation result applying the method of API 650 is more reasonable than other standards. While for the tanks made of high strength steel, like 12MnNiVR (GB 50341), the yield ratio of the steel has reached 0.803, which is larger than the upper limit value of API 650. In order to make up the deficiency, an optimization method based on API 650 is presented, which considers the effects of yield strength, tensile strength and yield ratio on the determination of allowable stress. Taking the 20×104 m3 oil storage tank and selecting a proper welded joint efficiency, the wall thickness is calculated by the presented optimization method. The wall thickness calculation result is more reasonable and the circumferential stress distribution is more homogeneous when the safety factor of tensile strength is taken to be 2.4. Results show that the optimization method is applicable to the thickness calculation of oil storage tanks made of high strength steel.

Determining the Subsidence of Oil Storage Tank Walls from Geodetic Leveling

2011 ◽  
Vol 367 ◽  
pp. 467-474 ◽  
Author(s):  
R. Irughe Ehigiator ◽  
J.O. Ehiorobo ◽  
M.O. Ehigiator ◽  
Ashraf A. Beshr
Keyword(s):  
Crude Oil ◽  
Least Squares ◽  
Storage Tank ◽  
Parallel Plate ◽  
Monitoring Network ◽  
Control Points ◽  
Storage Tanks ◽  
Estimation Model ◽  
Oil Storage ◽  
Oil Storage Tank

In this paper the monitoring for subsidence in crude oil storage tanks by the method of Geodetic leveling is discussed. The monitoring network consisted of three control points established about 100m from the tank and 16 studs established at the base of the tank. From the control points, the stud locations were leveled using a geodetic level with parallel plate micrometer and telescopic staves. All levels were run in forward and reverse directions and the measurements were carried out in 2003, 2004 and 2008. Adjustment of observation was carried out using the least squares estimation model to determine the elevation of each stud position in the three measurement epochs together with their accuracy standards. Comparisons were made of the calculated movements from the three measurement epochs and the associated accuracies calculated from the least squares model. Analysis of the results indicated that with the exception of one stud ( stud 8), all other studs emplaced had moved and the movements ranged from 0.91mm to 13.06mm

Stability Analysis of Local Thinned Shallow Spherical Roof of Oil Storage Tank

2008 ◽  
Vol 33-37 ◽  
pp. 1463-1470
Author(s):  
Zhi Chun Yang ◽  
Jiang Hua Liu ◽  
Bin Li ◽  
Le Wang ◽  
Bao Sheng Dong
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Critical Load ◽  
Storage Tank ◽  
Nonlinear Finite Element ◽  
Nonlinear Finite Element Method ◽  
Oil Storage ◽  
Oil Storage Tank ◽  
Corrosion Pit ◽  
Element Method

The analytical evaluation and finite element methods are used to analyze the critical stability of the shallow spherical roof of oil storage tank with an axial symmetrical corrosion region. At first, the nonlinear finite element method is adopted to calculate the global critical load of the storage tank roof, and the local corrosion region is equivalent to a circular corrosion pit with uniform depth. The results show that the tank wall and inner pressure of the stored oil have slight effects on the stability of the roof. To build the formula of local critical load of the tank roof, the circular corrosion pit is separated from the whole roof and treated as a shallow spherical shell which is elastically supported on the rest part of the roof. The equivalent support stiffness is obtained by the deformation compatibility at the edge of the corrosion pit. The resulted nonlinear stability equation is solved with a modified iteration method to determine the local critical load. The local critical load for an in-service corroded oil tank roof is analyzed by the proposed approach and the results are compared with those calculated by the conventional nonlinear finite element method with good agreement and the geometrical parameter of the corrosion region corresponding to the minimal critical load is 9.5.

Buckling of Oil Storage Tanks in SPPL Tank Farm During the 1979 Imperial Valley Earthquake

1987 ◽  
Vol 109 (2) ◽  
pp. 249-255 ◽  
Author(s):  
C.-F. Shih ◽  
C. D. Babcock
Keyword(s):  
Storage Tank ◽  
Reasonable Agreement ◽  
Laboratory Model ◽  
Base Excitation ◽  
Storage Tanks ◽  
Imperial Valley ◽  
Tank Farm ◽  
Oil Storage ◽  
Buckling Behavior ◽  
Oil Storage Tank

An oil storage tank that suffered damage during the 1979 Imperial Valley earthquake is studied using a laboratory model. The tank is unanchored and includes a floating roof. The tank is subjected to a single horizontal axis base excitation. Buckling is studied under both harmonic and simulated earthquake base motion. The model buckling results are in reasonable agreement with the field observations. It was also found that the floating roof has no effect on the buckling behavior. Comparison with the API design provisions shows that the empirical model used as the basis of the code for both tip-over and buckling have little resemblance to the actual tank behavior.

scholarly journals Corrosion and protection of island and offshore oil storage tank

2021 ◽  
Vol 252 ◽  
pp. 03035
Author(s):  
Miaoke Feng ◽  
Kaining He ◽  
Yanhong Zhao
Keyword(s):  
Corrosion Protection ◽  
Marine Environment ◽  
Storage Tank ◽  
Storage Tanks ◽  
Safety Hazards ◽  
Oil Storage ◽  
Potential Safety ◽  
Oil Storage Tank ◽  
Offshore Oil

This article is mainly based on the characteristics of the marine environment of islands and coastal seas and the current corrosion problems of storage tanks as well as their main locations, analyse the reasons for their formation and consider the potential safety hazards, so as to propose several effective storage tank corrosion protection methods, which has important positive significance for the long-term development of islands and coastal seas oil storage tanks.

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