Finite Element Analysis of Well Pads in Basra Province

2019 ◽  
Vol 7 (1) ◽  
pp. 73-86
Author(s):  
Haider Saad Al-Jubair ◽  
Hiba Abdul Hussein Saheb
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Bearing Capacity ◽  
Contact Pressure ◽  
Cohesionless Soil ◽  
Soil Profiles ◽  
The Finite Element Method ◽  
Safety Factors ◽  
Drilling Rigs ◽  
Element Method

After the year 2003, the oil / gas sector evolved and gained investment. International companies of different origins utilized heavy drilling rigs (to achieve high drilling depths) and entered our region. Meanwhile, some drilling problems were recorded, accompanied by well-pad failure cases. This research aims to study the behavior of well-pads with different geometric configurations, under the effects of drilling rigs with various characteristics, within the Basra province. Four case studies have been selected to represent four fields, namely: Siba, Zubair, West Qurna-2, and Zubair-Mishrif fields. The finite element method is utilized to conduct a stress analysis process, adopting an elastic–plastic constitutive relation for soil, based on Drucker-Prager's yield criterion. The maximum contact pressure applied on soil (under the working loads) is compared to its bearing capacity. When a rigid method is used to calculate the contact pressure, it is compared with the ultimate soil-bearing capacity, as calculated by Reddy and Srinivasan's method for cohesive soils, with allowable bearing capacity taken from the Peck, Hanson, and Thornburn's method for cohesionless soils. The contact pressure calculated via the finite element method is compared with the ultimate soil-bearing capacity calculated using the same method, based on a settlement of 50 mm. The extreme values of the bending moments and shear forces developed in the well-pad sections (under the factored loads), are compared with the section capacities calculated by using the ultimate strength design method. Regarding the geotechnical side, the results indicate insufficient safety factors against soil shear failure for some cases, especially for cohesive soil profiles.  For cohesionless soil profiles, the provided safety factors are sufficient. The finite element method reveals higher contact pressures compared to the conventional rigid method. For cohesionless soil profiles, the Peck, Hanson, and Thornburn's method, gives a bigger safety margin than the finite element method. The immediate settlement values are almost tolerable. Regarding the structural side, it has been identified that a uniform section is adopted for all locations of each pad, for individual wells. In most cases, the provided reinforcing steel is less than the minimum code requirement. This leads to a violation of the section capacity of bending, at least near the cellar. The beam shear capacity is rarely violated. Using strip footings beneath the rig skids, permits utilizing a heavy section that satisfies the requirements of structural safety, without violating the economic considerations.

Effect of Traffic Flow on Characteristics of Piezoelectric Harvesting Unit

2014 ◽  
Vol 672-674 ◽  
pp. 902-905 ◽  
Author(s):  
Chun Hua Sun ◽  
Guang Qing Shang
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Electric Power ◽  
Traffic Flow ◽  
Contact Pressure ◽  
Green Energy ◽  
The Finite Element Method ◽  
Oil Resources ◽  
Element Method

To protect dwindling coal and oil resources and open up a new way of renewable green energy, the technology of piezoelectric harvesting from pavement is proposed. Effect of traffic flow, including contact pressure and speed of a vehicle, on characteristics of a piezoelectric harvesting unit is discussed with the finite element method. Results show that the harvested electric power is approximately linear with the contact pressure and a vehicle’s speed. The contact pressure takes more effect on the harvested electric power and stress on pavement than the vehicle’s speed. A PHU of 280*280*20mm can harvest about 10mJ electric power when the contact pressure is 0.85MPa. That shows that application of the piezoelectric harvesting unit has very nice optimistic prospects.

Slope Stability Analysis of Jiu-Fen Using Finite Element Method and Limit Equilibrium Method

2012 ◽  
Vol 170-173 ◽  
pp. 1064-1067
Author(s):  
Shong Loong Chen ◽  
Chun Fu Lin
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Slope Stability ◽  
Displacement Vector ◽  
Limit Equilibrium ◽  
Limit Equilibrium Method ◽  
The Finite Element Method ◽  
Safety Factors ◽  
Equilibrium Method ◽  
Element Method

This study simulates the slope stability at Jiu-Fen, using the limit equilibrium method and the finite element method. The limit equilibrium method can find potential slide surfaces and safety factors rapidly. The advantage of the finite element method is that it utilizes more reasonable soil behavior and boundary conditions. A critical slide surface obtained by the limit equilibrium method can be compared with the displacement vector, stress field and location of plastic zone obtained by the finite element method. Furthermore, we can compare the safety factors produced by the two methods. This study shows that the safety factor from the limit equilibrium method is higher than that from the finite element method. The displacement analysis by the finite element method agrees well with the progressive slope failure. So, if we combine the two methods using monitored data in the field, we can analyze slope stability clearly.

Behavior of Square Hollow Section Steel Tubes Filled with Concrete under Different Loading Conditions

2014 ◽  
Vol 577 ◽  
pp. 1097-1103
Author(s):  
Tian De Jin ◽  
Lan Hui Guo
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Yield Strength ◽  
Bearing Capacity ◽  
Area Ratio ◽  
Loading Conditions ◽  
The Finite Element Method ◽  
Hollow Section ◽  
Core Concrete ◽  
Element Method

In this paper, the behavior of composite stub columns under different loading conditions is studied using the finite element method. The accuracy of the theoretical method is validated by comparing with the experimental results. The behavior of specimen under different loading conditions is analyzed. Then, based on the finite element method, the comparison of mechanical behavior under three typical loading conditions is studied. The results show that the difference on bearing capacity will become larger with the increase of steel area to concrete area ratio. For the core concrete loaded specimen with lower steel area-to-concrete area ratio, whose bearing capacity is the lowest, but its ductility is very good. With the increase of the steel yield strength, the bearing capacity will increase evidently for specimen loaded simultaneously. While for the specimen with only core concrete loaded, the steel yield strength has little influence except increase of ductility.

scholarly journals Method of Calculation Flexural Stiffness Over Natural Oscillations Frequencies

2018 ◽  
Vol 64 (4) ◽  
pp. 89-103
Author(s):  
A. Nesterenko ◽  
G. Stolpovskiy ◽  
M. Nesterenko
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Bearing Capacity ◽  
Flexural Stiffness ◽  
The Finite Element Method ◽  
Load Bearing Capacity ◽  
Natural Oscillations ◽  
Load Bearing ◽  
Resonance Frequencies ◽  
Element Method

AbstractThe actual load-bearing capacity of elements of a building system can be calculated by dynamic parameters, in particular by resonant frequency and compliance. The prerequisites for solving such a problem by the finite element method (FEM) are presented in the article. First, modern vibration tests demonstrate high accuracy in determination of these parameters, which reflects reliability of the diagnosis. Secondly, most modern computational complexes do not include a functional for calculating the load-bearing capacity of an element according to the input values of resonance frequencies. Thirdly, FEM is the basis for development of software tools for automating the computation process. The article presents the method for calculating flexural stiffness and moment of inertia of a beam construction system by its own frequencies. The method includes calculation algorithm realizing the finite element method.

Comparison of Analytical Solutions with Finite Element Solutions for Ultimate Bearing Capacity of Strip Footings

2013 ◽  
Vol 353-356 ◽  
pp. 3294-3303
Author(s):  
Zi Hang Dai ◽  
Xiang Xu
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Bearing Capacity ◽  
Analytical Solutions ◽  
Numerical Solutions ◽  
Slip Surface ◽  
Ultimate Bearing Capacity ◽  
The Finite Element Method ◽  
Strip Footings ◽  
Element Method

The finite element method is used to compute the ultimate bearing capacity of a fictitious strip footing resting on the surface of c-φ weightless soils and a real strip footing buried in the c-φ soils with weight. In order to compare the numerical solutions with analytical solutions, the mainly existing analytical methods are briefly introduced and analyzed. To ensure the precision, most of analytical solutions are obtained by the corresponding formulas rather than table look-up. The first example shows that for c-φ weightless soil, the ABAQUS finite element solution is almost identical to the Prandtls closed solutions. Up to date, though no closed analytical solution is obtained for strip footings buried in c-φ soils with weight, the numerical approximate solutions obtained by the finite element method should be the closest to the real solutions. Apparently, the slip surface disclosed by the finite element method looks like Meyerhofs slip surface, but there are still some differences between the two. For example, the former having an upwarping curve may be another log spiral line, which begins from the water level of footing base to ground surface rather than a straight line like the latter. And the latter is more contractive than the former. Just because these reasons, Meyerhofs ultimate bearing capacity is lower than that of the numerical solution. Comparison between analytical and numerical solutions indicates that they have relatively large gaps. Therefore, finite element method can be a feasible and reliable method for computations of ultimate bearing capacity of practical strip footings.

Finite Element Analysis for Unstiffened Overlapped CHS K-Joints Welded in Different Ways

2012 ◽  
Vol 446-449 ◽  
pp. 533-536
Author(s):  
Xiu Li Wang ◽  
Peng Chen ◽  
Wen Wei Yang
Keyword(s):  
Finite Element Method ◽  
Finite Element Analysis ◽  
Finite Element ◽  
Bearing Capacity ◽  
Ultimate Bearing Capacity ◽  
Ultimate Capacity ◽  
The Finite Element Method ◽  
Element Analysis ◽  
Element Method

In this paper，the ultimate bearing capacity of unstifened overlapped CHS K-joints is investigated by using the finite element method with influence of weld and non-weld on joint ultimate capacity under brace different bearing capacity. with angle of chord and brace is increasing ultimate capacity to lowed more and more small，which hidden weld is non-weld by one brace is pulled and other is pressured. ultimate capacity no influence to hidden welded and non-welded by both brace is pulled.

scholarly journals KAJIAN KEKUATAN BALOK KERATON DENGAN ANALISIS METODE ELEMEN HINGGA

2019 ◽  
Vol 3 (1) ◽  
pp. 113
Author(s):  
Sunarjo Leman ◽  
Fanniwati Itang ◽  
Jemy Wijaya
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Numerical Analysis ◽  
Bearing Capacity ◽  
Laboratory Testing ◽  
Laboratory Tests ◽  
The Finite Element Method ◽  
Numerical Research ◽  
Actual Size ◽  
Element Method

Penelitian numerik sebelumnya mengenai segmen Bata Keraton telah diperoleh kekuatan pikul segmen Bata Keraton adalah lebih kurang 1 ton/m2. Pada penelitian lain uji laboratorium dengan merangkai segmen Bata Keraton menjadi Balok Keraton diperoleh kekuatan pikul untuk bentang 2.0 meter berkisar antara 105-200 Kg dan bentang 3.0 meter berkisar antara 60-170 Kg. Penelitian menggunakan cara uji laboratorium membutuhkan material uji, struktur yang diuji dengan ukuran sebenarnya, sumber daya manusia untuk merakit dari bentuk segmen Bata Keraton tersebut menjadi bentuk Balok Keraton dengan besi tulangan serta membuat adukan spesi untuk merangkai Balok Keraton. Alternatif lain untuk mengetahui kapasitas pikul pada Balok Keraton adalah dengan melakukan analisa numerik menggunakan metode elemen hingga menggunakan perangkat lunak Autodesk Inventor Professional 2017. Pemodelan Balok Keraton untuk analisis numerik dibuat sama dengan kondisi Balok Keraton pada saat diuji di laboratorium dengan bentang 2 meter dan 3 meter. Pola pembebanan pada analisis numerik  dilakukan sama seperti pada uji laboratorium. Tujuan analisis numerik dengan metode elemen hingga ini adalah untuk mengetahui kapasitas pikul Balok Keraton dan membandingkan hasilnya dengan uji laboratorium. Hasil analisis pada penelitian ini diperoleh kapasitas pikul untuk Balok Keraton dengan bentang 2 meter menggunakan tulangan 8 mm dan 10 mm berkisar 80-110 Kg untuk 1 beban di tengah bentang dan untuk 2 beban berkisar 55-80 Kg/ perbeban, sedangkan untuk bentang 3 meter menggunakan tulangan 8 mm dan 10 mm diperoleh untuk 1 beban berkisar 65-85 Kg dan 2 beban berkisar 45-65 Kg/ perbeban. Hasil analisis numerik memberikan hasil kapasitas pikul beban lebih kecil 51-81 % dari pengujian di laboratorium. Previous numerical research on the Keraton Brick segment has obtained the strength of the Keraton Brick segment bearing weight is approximately 1 ton / m2. In another study the laboratory test by stringing the Bata Keraton segment into the Keraton Beam obtained the strength of the pikul for a span of 2.0 meters ranging from 105-200 kg and span of 3.0 meters ranging from 60-170 kg. Research using laboratory testing methods requires test materials, structures that are tested with actual size, human resources to assemble from the shape of the Keraton Bata segment into a Keraton Beam with reinforcing iron and make a specific mixture to assemble the Keraton Beams. Another alternative to determine the bearing capacity of the Keraton Beams is by conducting numerical analysis using the finite element method using Autodesk Inventor Professional 2017. The Keraton Beam Modeling for numerical analysis is made the same as the condition of the Keraton Beams when tested in a laboratory with a span of 2 meters and 3 meters . The pattern of loading in numerical analysis is done the same as in laboratory tests. The purpose of numerical analysis with finite element method is to determine the bearing capacity of the Keraton Beams and compare the results with laboratory tests. The results of the analysis in this study obtained bearing capacity for the KeratonBeams with a span of 2 meters using reinforcement 8 mm and 10 mm ranging from 80-110 kg for 1 load in the middle span and for 2 loads ranging from 55 to 80 kg / load, while for a span of 3 meters using 8 mm and 10 mm reinforcement obtained for 1 load ranging from 65 to 85 kg and 2 loads ranging from 45 to 65 kg / load. The results of numerical analysis give the result of a smaller load bearing capacity of 51-81% than in laboratory testing.

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