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Showing papers on "Submarine pipeline published in 1994"


Patent
11 Jul 1994
TL;DR: In this paper, a tower with adjustable clamps is used to grasp a pipe section from a ready rack and transfer the pipe section into the tower for addition of the pipe piece to the pipeline.
Abstract: An apparatus for near vertical laying of pipeline offshore. A support frame and movable deck on a lay vessel support a tower at the desired angle for pipe laying. The tower has a travel block that is movable between open and closed positions for receiving a pipe section and supporting the weight of the pipe or pipeline. The travel block is adapted for movement along the length of the tower for raising or lowering the pipe and pipeline. A pedestal that is movable between open and closed positions for receiving a pipe section and supporting the weight of the pipeline is positioned near the bottom of the tower and adapted to transfer the weight of the pipeline from the travel block to the pedestal without the need to open the travel block. A strongback with adjustable clamps is used to grasp a pipe section from a ready rack and transfer the pipe section into the tower for addition of the pipe section to the pipeline. The strongback is guided into and up the tower by rails. A stinger extends down from the lower end of the tower and is provided with clamps to grip the pipeline during operations. The main portion of the stinger may be pivoted up adjacent the lay vessel when pipe laying operations are not in progress.

79 citations


Patent
07 Sep 1994
TL;DR: In this article, an offshore fluid transfer system is described, for transferring fluid between stations (12, 14, FIG. 1) that may be many kilometers apart and lie in deep water, which avoids the need for making fluid connections at great underwater depths.
Abstract: An offshore fluid transfer system is described, for transferring fluid between stations (12, 14, FIG. 1) that may be many kilometers apart and lie in deep water, which avoids the need for making fluid connections at great underwater depths. A buoy station (14) includes a buoy (40) anchored to the seafloor to lie a moderate distance below the sea surface, and coupled through a flexible hose (46) to a turret (52) that is attached to a weathervaning vessel (30) and that is anchored to the seafloor. A major conduit portion (34) which extends between the first station and the buoy, includes a long pipeline of series-connected steel pipes that extends along the seafloor to near the buoy station, with an end portion (32) of the pipeline extending in a J-curve and in a primarily upward direction to the underwater buoy.

26 citations


Journal Article
TL;DR: In this article, a series of physical equilibrium conditions, including the major mechanical forces involved in particle movement, are used to derive an analytical model, where x is a function of y, in relation with the offshore wave period (or wave length).
Abstract: The Submarine Profile (SP) is the sea floor profile normal to the coast line, located between the surf zone and wave base and formed by wave action on the clastic sediment. The Submarine Equilibrium Profile (SEP) is a SP where geometry and sediment movement are in a quasi equilibrium status with offshore nominal waves (the large swell dominating this area). The geometry of the SEP has been identified qualitatively and conceptually as a concave upward smooth curve. The slope of SEP becomes gentler and gentler offshore until it is almost horizontal at the so-called wave base. Some empirical equations have been proposed and are used widely in engineering. This report summarizes previous field observations, lab experiments and theories concerning mechanisms involved in the formation of this geometry. A series of physical equilibrium conditions, including the major mechanical forces involved in particle movement, are used to derive an analytical model. This model expresses the geometry of the SEP in an explicit form where x is a function of y, in relation with the offshore wave period (or wave length). The basic idea has been qualitatively tested in a wave tank experiment. The final equation was then tested and calibrated on a number of submarine profiles plotted from three marine basins around the U.S. using a non-linear regression algorithm. The profiles located on the U.S. coasts along the Gulf of Mexico and on southeast U.S. Atlantic coasts were selected following geological and visual criteria which previous researches used to characterize the SEP concept. The comparison between the theoretical equation and the selected Gulf of Mexico and Atlantic profiles by a non-linear computer regression process showed a satisfactory match with high correlation coefficients. The Pacific profiles, located in an area with ongoing active tectonic movement are generally not in SEP status and have more features deviating from the conceptual and SEP physical models. The wave periods obtained from the nonlinear regression process for some SEP's on the Gulf of Mexico coast are further compared with the available hindcast offshore wave data published in 1989. The results of these comparisons are generally encouraging, except those comparisons involving SP's on the U.S. Pacific coast.

16 citations


31 Dec 1994
TL;DR: In this article, a submarine pipeline gas transportation system crossing the Sicily Channel, in the Mediterranean Sea, at a maximum water depth of 610 m, is described, and the critical aspects concerning data acquisition, processing and management are analyzed and the planned developments are presented.
Abstract: TRANSMED is a submarine pipeline gas transportation system crossing the Sicily Channel, in the Mediterranean Sea, at a maximum water depth of 610 m. It went into operation in 1981. Initially composed of three lines, it has been increased to five lines and to a total length of 780 Km in the last year. In the present paper criteria, methodology and equipment used for the periodic inspection surveys of TRANSMED and for the management of gathered data are presented. The twelve years inspection activity and the relevant results of data analysis, mainly the historical evolution of scour induced free spans and the incidence of other hazards, are illustrated. Moreover, the critical aspects concerning data acquisition, processing and management are analyzed and the planned developments are presented.

15 citations


Journal Article
TL;DR: The Kutubu pipeline as discussed by the authors was built for Chevron Niugini, Papua, New Guinea to transport oil from a remote oil production facility in the Southern Highlands to an offshore loading facility.
Abstract: The 261-km long 500-mm diam Kutubu pipeline, which runs through dense jungle swamps in Papua, New Guinea, was built for Chevron Niugini to transport oil from the remote Kutubu oil production facility in the Southern Highlands to an offshore loading facility. The pipeline was laid with a section in the bed of a wide, fast-flowing river. This section was subject to substantial telluric effects and current density variations from changing water resistivities. The cathodic protection system's effectiveness was monitored by coupon off'' potentials and required an innovative approach.

4 citations


Journal Article
TL;DR: The first phase of the Zeepipe pipeline development included a 814km (506 mile), 40in gas pipeline from the Sleipner Field in the Norwegian North Sea to Zeebrugge, Belgium as discussed by the authors.
Abstract: The first phase of the Zeepipe development included a 814-km (506-mile), 40-in gas pipeline from the Sleipner Field in the Norwegian North Sea to Zeebrugge, Belgium The pipeline, which is more than twice as long as the next largest single-section offshore pipeline in the world, was constructed and commissioned in 1991--1993 Commissioning concepts developed for Zeepipe included a sophisticated pipeline de-watering method and a novel high-pressure gas drying concept The successful operations during start-up of the Zeepipe pipeline have set new standards for commissioning long-distance gas pipelines On the basis of the Zeepipe experience, pigging and commissioning of coated pipeline sections more than 1,000 km (620 miles) long is feasible without expensive intermediate pigging stations The Zeepipe is internally coated with epoxy to reduce pipe wall roughness and minimize corrosion during storage and construction The high-pressure drying concept eliminates flaring of drying gas, reducing the environmental impact, and significantly shortens commissioning time This allows gas deliveries to begin immediately after the dewatering operation is completed The corrosion inhibition method used resulted in lower chemical consumption than with conventional techniques, reducing costs and environmental problems

3 citations


Journal Article
TL;DR: A 30-inch oil pipeline, presently under construction through mountainous terrain in central Colombia, transports petroleum from the Cusiana oil field to the coast as mentioned in this paper, and a major area of concern is the restoration and protection of the pipeline right-of-way against slope failures and erosion.
Abstract: A 30-inch oil pipeline, presently under construction through mountainous terrain in central Colombia, transports petroleum from the Cusiana oil field to the coast. The discovery of the Cusiana oil field 100 miles east of Bogota has been described as the largest find in the Americas since the Prudhoe Bay field in Alaska in 1969. High rainfall, steep unstable slopes, difficult access, environmental constraints, and attacks by guerrilla forces characterize the pipeline construction project. The basic routing strategy has been to follow ridge lines where possible or to locate the pipeline on midslope, cut benches. Even so numerous stream crossings are required, and the right-of-way plunges up and down repeatedly. A major area of concern is the restoration and protection of the pipeline right-of-way against slope failures and erosion. Basic principles of erosion/sediment control have been invoked effectively during construction of the pipeline during its various phases. Handling excess runoff and mitigating the impact of disturbed hillside hydrology following clearing and grading operations along the pipeline right-of-way have been key factors in minimizing adverse environmental impacts of the pipeline construction. Conventional erosion control measures, appropriately modified to meet local site conditions, have been successful for the most part. These range from the widespread use of cross slope drains to surface vegetative treatments.

3 citations


31 Dec 1994
TL;DR: In this article, the authors outline a design methodology that is based on phenomenological studies of ice scoured terrain, both modern and relict, laboratory tests, centrifuge modeling, and numerical analysis.
Abstract: Large areas of the continental shelf of northern oceans are frequently scoured or gouged by moving bodies of ice such as icebergs and sea ice keels associated with pressure ridges. This phenomenon presents a formidable challenge when the route of a submarine pipeline is intersected by the scouring ice. It is generally acknowledged that if a pipeline, laid on the seabed, were hit by an iceberg or a pressure ridge keel, the forces imposed on the pipeline would be much greater than it could practically withstand. The pipeline must therefore be buried to avoid direct contact with ice, but it is very important to determine with some assurance the minimum depth required for safety for both economical and environmental reasons. The safe burial depth of a pipeline, however, cannot be determined directly from the relatively straight forward measurement of maximum scour depth. The major design consideration is the determination of the potential sub-scour deformation of the ice scoured soil. Forces transmitted through the soil and soil displacement around the pipeline could load the pipeline to failure if not taken into account in the design. If the designer can predict the forces transmitted through the soil, the pipeline can be designedmore » to withstand these external forces using conventional design practice. In this paper, the authors outline a design methodology that is based on phenomenological studies of ice scoured terrain, both modern and relict, laboratory tests, centrifuge modeling, and numerical analysis. The implications of these studies, which could assist in the safe and economical design of pipelines in ice scoured terrain, will also be discussed.« less

3 citations


Book ChapterDOI
01 Jan 1994
TL;DR: In this article, the authors examined the application of innovative technology to significantly reduce the time for a major repair to a 36-inch diameter buried submarine pipeline, and proposed a method to improve the reliability of the pipeline.
Abstract: This paper examines the application of innovative technology to significantly reduce the time for a major repair to a 36 inch diameter buried submarine pipeline.

2 citations



31 Dec 1994
TL;DR: In this article, a procedure for assessing the consequence of an underwater explosion just in the vicinity of a submarine pipeline is presented, where global (beam) and local (shell) response as well as structural integrity assessment is described.
Abstract: The presence of unexploded mines, bombs or torpedoes on the seabed in areas which in the recent past were war theater constitute a potential hazard for the structural integrity of submarine pipelines This paper presents a procedure for assessing the consequence of an underwater explosion just in the vicinity of a submarine pipeline Global (beam) and local (shell) response as well as structural integrity assessment will be described The main parameters will be evaluated and discussed

Journal Article
TL;DR: A real-time dynamic two-phase model of the pipeline system and relevant portions of shore facilities is being installed for Woodside Offshore Petroleum Pty. Ltd.'s North West Shelf gas project.
Abstract: A real-time dynamic two-phase model of the pipeline system and relevant portions of shore facilities is being installed for Woodside Offshore Petroleum Pty. Ltd.'s North West Shelf gas project. The trunkline management system (TMS) which utilizes dynamic pipeline and plant process simulation is scheduled to start up near the end of the first quarter of 1994 at Woodside Offshore's plant at Karratha, Western Australia. The TMS is a real-time dynamic two-phase model of the pipeline system and relevant portions of the onshore facilities. Its budget was approximately $4 million (Australian). This concluding of two articles describes the models incorporated in the system. Part 1 described the operating conditions that prompted the systems's installation.

01 Dec 1994
TL;DR: In this paper, an optimization method for pipe supporting roller setting is presented and computer modelling techniques of the pipelay equipment to improve the installation analysis are also suggested, and various methods of onshore and offshore pipeline initiations are described.
Abstract: Advanced analysis techniques for offshore pipeline installation are introduced. Offshore pipelay equipment is briefly described and an optimization method for pipe supporting roller setting is presented. Computer modelling techniques of the pipelay equipment to improve the installation analysis are also suggested. Various methods of onshore and offshore pipelay initiations are described.

Book ChapterDOI
01 Jan 1994
TL;DR: In particular, nearshore and landfall sections of submarine pipelines need to cross very difficult variable terrain, for example, shallow water, tidal flats, shipping lanes, etc. as discussed by the authors.
Abstract: Worldwide expansion of offshore hydrocarbon exploration and the necessity to transport products to users on land presents many technical and environmental challenges. In particular, nearshore and landfall sections of submarine pipelines need to cross very difficult variable terrain, for example, shallow water, tidal flats, shipping lanes, etc. These areas are often exposed to extreme hydrodynamic conditions, geomorphical activity and other hazards. Furthermore, the increasing concern regarding ecological impact caused by the construction and operation of pipelines represents a major challenge to the industry.

Book ChapterDOI
01 Jan 1994
TL;DR: In this paper, the authors discuss the design of offshore structures used for oil and gas production and the physical processes that govern interactions between the atmosphere and the ocean surface and the effect of the structure on the fluid around it and on the behavior of the seabed foundation.
Abstract: Publisher Summary This chapter discusses the designs of offshore structures used for oil and gas production. A typical steel-framed jacket structure used for offshore oil drilling and production will encounter steady environmental forces from wind and current flows and from the structure's weight. At the same time, the physical processes that govern interactions between the atmosphere and the ocean surface and the effect of the structure on the fluid around it and on the behavior of the seabed foundation are not completely understood in scientific terms. The technical evolution of the modern offshore industry can be measured by increases in the depth at which it has been able to carry out exploration drilling and by the improvements in the structures or vessels that have made such drilling possible. The ocean depth at which exploration drilling is carried out is an indicator of future requirements for oil production. In drilling programs, a decision on oil production is dependent on the prevailing price of oil and the economics of platform construction and fixed platform design based on the use of concrete to create a large, heavy structure, which can rest on the seabed and remain stable under its own weight.