scholarly journals STABILITY AND ENGINEERING EFFECT OF SHOALS AND CHANNELS IN CAOFEIDIAN DEEP-WATER HARBOR AREA, CHINA

2011 ◽  
Vol 1 (32) ◽  
pp. 38 ◽  
Author(s):  
Yongjun Lu ◽  
Rongyao Ji ◽  
Liqin Zuo
Keyword(s):  
Deep Water ◽  
Tidal Currents ◽  
Bohai Bay ◽  
Natural Conditions ◽  
Coastal System ◽  
System Formation ◽  
Seabed Evolution ◽  
The Stability ◽  
Sea Area ◽  
Harbor Area

Caofeidian sea area is the only natural site suitable for building a large-sized berth of 300 000 tons without excavation of waterways and harbor basins in Bohai Bay. In Caofeidian harbor area, the stability of the shoals-inlets coastal system under natural conditions is a key point. The harbor could be developed only if the coastal system is stable. In this paper the characteristics of waves, tidal currents, sedimentation and seabed evolution in the Caofeidian shoal area is briefly described, and the trend of stability of shoals and channels is predicted based on research on the coastal system formation. Engineering effect of some projects, such as the dam linking the Caofeidian Island and the coastline, the shoal reclamation and ore terminal construction, is also studied. The analysis show that deposition and erosion of the seabed in front of Caofeidian foreland will reach its equilibrium in 2～3 years after the implementation of the proposed scheme.

Analysis on the Tidal Current Characteristics of the Caofeidian Sea Area

2011 ◽  
Vol 250-253 ◽  
pp. 3050-3054
Author(s):  
Cui Ping Kuang ◽  
Kai Hua Yao ◽  
Jie Gu ◽  
Huang Jing ◽  
Xu Liu
Keyword(s):  
Deep Water ◽  
Tidal Current ◽  
Reverse Flow ◽  
Eastern Coast ◽  
Bohai Bay ◽  
Field Observations ◽  
Current Characteristics ◽  
Flood Current ◽  
Under Construction ◽  
Sea Area

Caofeidian harbor is a large size deep-water harbor currently under construction in the Bohai Bay, the eastern coast of north China. The construction began in 2003. The characteristics of tides and tidal currents in the Caofeidian area are analyzed with field data from comprehensive field observations from 2008 to 2010. The field observations and analysis show that the tide is the irregular semi-diurnal and tidal current is characterized as a type of reverse flow with moving west during flood tides and east during ebb tides. In general, the flood current is slightly stronger than the ebb current, and the strongest tidal current appears in the Caofeidian foreland, which is the predominant driving force to maintain the deep water depth.

scholarly journals Elements constituent for the design of a riser system in areas deep water and extreme deep water applied for offshore drilling

2020 ◽  
Vol 6 (3) ◽  
pp. 127-144
Author(s):  
Marius STAN ◽  
◽  
Valentin Paul TUDORACHE ◽  
Lazăr AVRAM ◽  
Mohamed Iyad AL NABOULSI ◽  
...  
Keyword(s):  
Working Conditions ◽  
Water Depth ◽  
Deep Water ◽  
Environmental Conditions ◽  
Oil And Gas ◽  
Operational Mode ◽  
Exploration And Exploitation ◽  
Offshore Drilling ◽  
The Stability ◽  
Marine Platform

Riser systems are integral components of the offshore developments used to recover oil and gas stored in the reservoirs below the earth’s oceans and seas. These riser systems are used in all facets of the development offshore process including exploration and exploitation wells completion/intervention, and production of the hydrocarbons. Their primary function is to facilitate the safe transportation of material, oil and gases between the seafloor oceans and seas and the marine platform. As the water depth increases, the working conditions of this system becomes challenging due to the complex forces and extreme environmental conditions which are impacting the operational mode as well as the stability. In this paper several aspects concerning riser mechanics and the behaviour of the riser column will be evaluated against different operational situations.

Independence, dimension and continuity in non-forking frames

2013 ◽  
Vol 78 (2) ◽  
pp. 602-632 ◽  
Author(s):  
Adi Jarden ◽  
Alon Sitton
Keyword(s):  
Continuity Property ◽  
Natural Conditions ◽  
Elementary Class ◽  
Independence Dimension ◽  
The Stability ◽  
Abstract Elementary Class

AbstractThe notion J is independent in (M, M0, N) was established by Shelah, for an AEC (abstract elementary class) which is stable in some cardinal λ and has a non-forking relation, satisfying the good λ-frame axioms and some additional hypotheses. Shelah uses independence to define dimension.Here, we show the connection between the continuity property and dimension: if a non-forking satisfies natural conditions and the continuity property, then the dimension is well-behaved.As a corollary, we weaken the stability hypothesis and two additional hypotheses, that appear in Shelah's theorem.

Effect of the environment on processing and handling materials at sea

1978 ◽  
Vol 290 (1366) ◽  
pp. 161-177 ◽  
Keyword(s):  
Deep Water ◽  
Seasonal Variations ◽  
Deep Sea ◽  
Weather Conditions ◽  
Floating Structure ◽  
Mining Operations ◽  
Waste Products ◽  
The Stability ◽  
Vast Range ◽  
Significant Factors

Compared with conventional land-based mining and processing operations, the exploitation of minerals from the seabed, particularly in deep water, involves a vast range of new problems in conducting the various stages of mining, transportation, processing and disposal of waste products, in a marine environment. In all such operations the ways in which local sea and weather conditions and their seasonal variations affect the stability of the vehicle, be it ship or other floating structure or submersible from which the operations are being conducted, have to be taken into account. The resulting motion together with vibration generated by propulsion and other machinery are significant factors in the performance and behaviour of equipment and materials during processing, handling and transportation operations at sea. In deep-sea mining operations at depths of 2-5 km the effects of associated pressure, salinity and temperature must also be dealt with. The paper reviews the present state of such knowledge as currently practised in continental-shelf operations, and as proposed in various deep-sea mining operations. Associated research requirements for future mineral exploitation in the deep-sea environment are discussed.

Dynamic Stability of FPSO-Shuttle Systems: An Analytical Procedure and Practical Results

2002 ◽  
Author(s):  
Ge´rson B. Matter ◽  
Joel S. Sales ◽  
Sergio H. Sphaier
Keyword(s):  
Dynamic Stability ◽  
Deep Water ◽  
Dynamic Systems ◽  
Time Domain ◽  
Equilibrium Position ◽  
Analytical Procedure ◽  
Time Domain Analysis ◽  
The Stability ◽  
The Time Domain ◽  
Floating Systems

The paper deals with the dynamics of floating systems (FPSO units) moored in deep water in the presence of currents. The offloading operation is carried out in a tandem arrangement from the FPSO to a Shuttle ship of lesser capacity. According to the classical theory of dynamic systems, a study of the behavior of floating units is performed by determining the equilibrium position and then analyzing the stability around this position. The time domain analysis is also used to compare the results. This procedure is extended to the case of systems in a spread mooring configuration and with turret.

Hydraulic Sytem for Wave Compensation of Deep-Water Exploration Ship

2012 ◽  
Vol 192 ◽  
pp. 201-206
Author(s):  
Zhi Xin Chen ◽  
Shuai Liu
Keyword(s):  
Deep Water ◽  
Structural Parameters ◽  
Dynamic Performance ◽  
Wire Rope ◽  
Transmission System ◽  
Compensation System ◽  
Work Condition ◽  
Extraction Equipment ◽  
The Stability ◽  
Heave Motion

In order to reduce the influence of the bench extraction equipment from the working deep-water exploration ship when it has swing or heave movement by wind and waves, according to the work condition and the structural parameters of 3000m deep-water exploration ship, Pump-controlled type and valve-controlled type hydraulic transmission system for waves compensation of deep-water exploration ship bench extraction equipment was researched through analysing and calculating. Wire rope which drags the bench is maintained appropriate tensioning status using this wave compensation system, when bench downs to the bottom of the sea. This system can bind and release wire rope to compensate for heave motion automatically, in order to keep the stability and security of the deep-water exploration ship before bench loading the bottom. Dynamic performance of wave compensation system is improved through controlling supplementation pressure and the accumulator parameters precisely.

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