Minimum Structure for Well Appraisal in Marginal Fields at 35m Water Depth without Jacket & Mudline Suspension System

2021 ◽  
Author(s):  
Prabir Kumar Chatterjee
Keyword(s):  
Structural Design ◽  
Dynamic Effect ◽  
Well Testing ◽  
Wave Loads ◽  
Environmental Loads ◽  
High Wave ◽  
Drilling Rig ◽  
Mat Foundations ◽  
Wave Induced ◽  
Reserve Strength

ABSTRACT This paper proposes a minimum structure for drilling two appraisal wells. Conductors will be driven into seabed by a crane vessel or drilling-rig crane through a pre-installed lightweight guide-frame placed on seabed. After driving the conductors to required depth, the frame is raised and joined to the conductors at appropriate elevation by bolted and grouted connections. Six tie members connected between the frame and seabed by specially-designed small mat foundations will ensure stability of the structure against environmental loads. A small deck will be installed on the top of conductors to provide space for essential equipment required for prolonged well testing after departure of drilling rig. The platform will be accessed by small boats through a boat landing and ladder. In case of positive drilling outcome, a riser and flexible pipeline will be added to connect with the nearest subsea tie-in point. A detailed structural design of the minimum facility is performed to withstand omnidirectional environmental loads due to 10.0m high wave along with associated wind and current loads. Susceptibility of the structure against dynamic effect of wave loads is also investigated. Demonstration of structural adequacy against wave-induced fatigue loads and reserve strength against extreme environmental loads show the robustness of the minimum structure to perform against design environmental loads.

Numerical Analysis of Ship Wave Loads and Structure Strengthen Analysis on a Wind Power Installation Ship

2011 ◽  
Vol 90-93 ◽  
pp. 2521-2527
Author(s):  
Gang Qiang Li ◽  
Yan Yan Zhao ◽  
Yong He Xie
Keyword(s):  
Wind Power ◽  
Structural Design ◽  
Three Dimensional ◽  
Load Condition ◽  
Wave Loads ◽  
Element Simulation ◽  
Wind Power Installation ◽  
Wave Induced ◽  
Term Response

In a typical load condition of wind power equipment Installation ship, using the three-dimensional potential flow theory to prediction the long-term response of wave induced loads. then using the main load control parameters as a basis for the design wave selection, then application of DNV's SESTRA program make the wave-induced directly to the structure to finite element simulation. The results show that the hull structural design can meet the requirements.

Prediction of Ship Response Statistics in Severe Sea Conditions Using RANS

2012 ◽  
Author(s):  
Jan Oberhagemann ◽  
Jens Ley ◽  
Bettar Ould el Moctar
Keyword(s):  
Structural Design ◽  
International Association ◽  
Rayleigh Distribution ◽  
Ship Motions ◽  
Wave Loads ◽  
Large Wave ◽  
Hull Girder ◽  
New Methods ◽  
Design Loads ◽  
Wave Induced

The International Association of Classification Societies (IACS) promotes the paradigm shift in structural design rules for ships towards risk based approaches. This requires improvements in the assessment of structural design loads and new methods for estimation of wave loads and responses, amongst others with respect to extreme value distributions. In this paper we present a numerical method based on the solution of RANS equations to deal with large wave-induced ship motions and corresponding loads for different ship types. Nonlinearities of wave excitation and ship response are included. Short-term ship response distributions from time domain simulations are compared with model test data. Significant deviations from Rayleigh distribution of amplitudes are observed, especially for hull girder loads including effects of structural elasticity.

Influence of Wave-Induced Uplift Forces on Upheaval Buckling of Pipelines Buried in Sandy Seabeds

2019 ◽  
Vol 141 (4) ◽  
Author(s):  
D. Suresh Kumar ◽  
D. Achani ◽  
M. R. Sunny ◽  
T. Sahoo
Keyword(s):  
Gravity Waves ◽  
Shallow Waters ◽  
Burial Depth ◽  
Theoretical Studies ◽  
Wave Loads ◽  
Upheaval Buckling ◽  
Consolidation Model ◽  
Wave Induced ◽  
Uplift Forces ◽  
Experimental And Theoretical Studies

This study focuses on the buckling of pipelines in shallow waters subjected to surface gravity waves. The wave-induced uplift forces on pipelines buried in sandy seabeds are investigated using Biot's consolidation model. Empathetic imperfection model proposed by Taylor and Tran (1994, “Experimental and Theoretical Studies in Subsea Pipeline Buckling," Mar. Struct., 9(2), pp. 211–257.) is used for the study. Thereafter, buckling analyses are performed on the pipeline with the combined temperature and the wave-induced loads. The differences in the critical buckling temperatures for the pipe with consideration of wave loads are analyzed within a range of sea states. The influence of wave loads is found significant for low burial depth ratios.

scholarly journals EXPERIMENTAL DATA AND NUMERICAL SIMULATION OF WAVE LOADING AND ITS REDUCTION ON SHELTERED BUILDINGS

2020 ◽  
pp. 21
Author(s):  
Joaquin Moris ◽  
Andrew Kennedy ◽  
Joannes Westerink
Keyword(s):  
Experimental Data ◽  
Numerical Simulation ◽  
Structural Design ◽  
Structural Damage ◽  
Wave Loads ◽  
Wave Loading

Wave loading from inundation events like storms and tsunamis can cause severe structural damage to buildings (Xian et al., 2015); therefore, it is important to predict wave loading as accurately as possible. One uncertainty in estimating wave loads during inundation events is the possible reduction of loads by sheltering from other buildings. Understanding and quantifying this effect could reduce overestimated loads in sheltered buildings and avoid over-conservative structural design. This work aims to quantify the reduction of wave loads in sheltered buildings through the analysis of experimental data and numerical simulations.Recorded Presentation from the vICCE (YouTube Link): https://youtu.be/89QblLjDBnI

scholarly journals WAVE LOADS ON HORIZONTAL CYLINDERS

1978 ◽  
Vol 1 (16) ◽  
pp. 147
Author(s):  
P. Holmes ◽  
J.R. Chaplin
Keyword(s):  
Oscillatory Flow ◽  
Vertical Plane ◽  
Vertical Cylinder ◽  
Irregular Waves ◽  
Wave Loads ◽  
Incident Flow ◽  
Cylinder Axis ◽  
Straight Line ◽  
Horizontal Cylinders ◽  
Wave Induced

The problem of predicting wave induced loads on cylinders is an enormously complex one. It is clear from the scatter present in most experimental determinations of force coefficients that there are many individual factors which influence the mechanisms of flow induced loading. Among these are some, for instance Reynolds number, separation and periodic vortex shedding, which are inter-related and whose influences cannot be studied in isolation. Others, such as shear flow, irregular waves and free surface effects, can at least be eliminated in the laboratory, in order to approach an understanding of the more fundamental characteristics of the flow. A vertical cylinder in uniform waves experiences an incident flow field which can be described in terms of rotating velocity and acceleration vectors, always in the same vertical plane, containing also the cylinder axis, whose magnitudes are functions of time and of position along the length of the cylinder. Some of the essential features of this flow can be studied under two-dimensional oscillatory conditions, in which either the cylinder or the fluid is oscillated relative to the other along a straight line (planar oscillatory flow). The incident velocity and acceleration vectors are then always concurrent, normal to the cylinder axis, and oscillating in magnitude with time.

Design of Hydraulic Station of Crawler Hydraulic Drilling Rig

2014 ◽  
Vol 889-890 ◽  
pp. 380-384
Author(s):  
Zhi Liu ◽  
Peng Fang ◽  
Di Wu ◽  
Dong Li
Keyword(s):  
Design Process ◽  
Structural Design ◽  
Control Technique ◽  
Pumping Station ◽  
Drilling Rig ◽  
Pumping Stations ◽  
Hydraulic Station ◽  
Scheme Selection ◽  
And Control

This article describes the design process of pumping stations of crawler full hydraulic drilling rig. The principle of full hydraulic drilling rig pumping station,scheme selection, hydraulic components selection and structural design of the tank were presented. The system used double loops in which some advanced hydraulic components and control technique were adopt.

Non Linear Effect on Wave-Induced Loads for Hull Structural Design -Vehicles Carrier, Bulk Carrier, Container Carrier-

2021 ◽  
Author(s):  
Kei Sugimoto ◽  
Yusuke Fukumoto ◽  
Hiroshi Kawabe ◽  
Kinya Ishibashi ◽  
Hidetaka Houtani ◽  
...  
Keyword(s):  
Structural Design ◽  
Bulk Carrier ◽  
Linear Effect ◽  
Non Linear Effect ◽  
Non Linear ◽  
Wave Induced

Probabilistic Analysis of the Combined Slamming and Wave-Induced Responses

1985 ◽  
Vol 29 (03) ◽  
pp. 170-188
Author(s):  
G. Ferro ◽  
A. E. Mansour
Keyword(s):  
Sensitivity Analysis ◽  
Stochastic Modeling ◽  
Structural Design ◽  
Arrival Time ◽  
Extreme Value ◽  
Induced Responses ◽  
Combined Load ◽  
Random Intensity ◽  
Important Input ◽  
Wave Induced

The success of implementing reliability analysis in structural design depends to a large extent on the ability to combine the loads acting on the structure, and on extrapolating their magnitudes to obtain the extreme value of the total combined load. In this paper, a new theory is proposed to combine the slamming and wave-induced responses of a ship moving in irregular seas. The slamming and wave-induced responses are both considered as stochastic processes, and the properties of the combined response are determined on that basis. The slamming loads alone are considered as a train of impulses of random intensity and random arrival time as has been shown by Mansour and Lozow [1],3 but the dependence between the intensity and arrival time is considered in the stochastic modeling. The extreme value of the combined response is then investigated for use in design applications. An example of application to a cargo ship is given and a sensitivity analysis is conducted to determine how sensitive the results are to some of the important input parameters.

Hydrodynamic Response of Multiple Fish Cages Under Wave Loads

2014 ◽  
Author(s):  
Ke Hu ◽  
Shixiao Fu ◽  
Yuwang Xu ◽  
Leixin Ma ◽  
Yifan Chen
Keyword(s):  
Element Model ◽  
Mooring Line ◽  
Wave Loads ◽  
Fish Farms ◽  
Mooring Lines ◽  
Marine Aquaculture ◽  
Wave Propagation Direction ◽  
Environmental Loads ◽  
Hydrodynamic Response ◽  
Fish Cages

Nowadays, marine aquaculture is playing an important role in meeting people’s ever increasing need for sea foods high in protein. The multiple fish cages are commonly used in large fish farms currently. Mooring systems in these fish cages should be strong enough to withstand extreme environmental loads. Thus, a reliable mooring system is required in designing safe structures. In this paper, a finite element model is built. The floating collar is simulated by the beam element, the twine of the net and the mooring lines are simulated by the truss elements. The geometric nonlinearity of the net model and the material nonlinearity of the mooring line are considered. In this analysis, the hydrodynamic forces estimated by Morison equations are applied to the model. The hydrodynamic response of multiple fish cages under the wave loads by considering the pretension of mooring line is carefully studied. The maximum tension in mooring lines under different wave propagation direction is also analyzed in this study.

Advanced Integrated Design Method for Fatigue Assessment of Large Elastic Ship Structures

2013 ◽  
Vol 371 ◽  
pp. 443-447
Author(s):  
Ionica Rubanenco ◽  
Iulia Mirciu ◽  
Leonard Domnisoru
Keyword(s):  
Service Life ◽  
Hot Spot ◽  
Ratio Method ◽  
Wave Loads ◽  
Ship Structures ◽  
Fatigue Assessment ◽  
Integrated Method ◽  
Oscillation Analysis ◽  
Non Linear ◽  
Wave Induced

This paper is focused on an advanced method for ship structures fatigue assessment. The ships classification societies standard rules for fatigue analysis are based on simplified procedures, with wave induced loads obtained by linear oscillation analysis (low frequency, around 0.1 Hz), or equivalent statistical wave loads. In the case of large elastic ship structures, with hull length over 150 m, the global wave induced vibration response (high frequency, around 1 Hz) becomes significant. The developed integrated method for large ships fatigue assessment includes three interlinked analyses, as follows: the hot-spot stresses evaluation by 3D finite element models, wave induced loads by short term linear and non-linear hydroelastic dynamic analysis, ship service life and fatigue assessment by damage cumulative ratio method. As testing ship, it is considered a double hull LPG Liquefied Petroleum Gas carrier, with total length 239 m, for a set of structural details with stress hot-spots. Based on the non-linear hydroelastic wave loads, the integrated method of fatigue assessment becomes more accurate, predicting for the amidships structure 14 years of ship service life, instead of over 20 years according to the rules standard approach, so that the confidence on ship structure fatigue evaluation can be increased in the design process.

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