Ffshr ilins and i-In Sls - Essay Example

FFSHОRЕ РIРЕLINЕS АND ТIЕ-IN SРООLS Name Course Institution Instructor Date ОFFSHОRЕ РIРЕLINЕS АND ТIЕ-IN SРООLS Pipelines Although rarely considered, pipes form the ubiquitous substrate that supports humanity as we hurdle towards the future with ever-increasing rapidity. They are one of the simplest forms of technology, created simply by enclosing space and separating the contents within from the rest of the environment. Due in part to their apparent simplicity, there are a latticework of pipelines traversing an unseen world beneath our very feet. Humanity’s relationship to the immense complexity of these structures takes a variety of forms; the reactions and effects of pipes on lived human experience is shaped by how visible (or invisible) these pipes are to a critical human gaze. Because of its material qualities, the visibility of a pipe has an array of implications when the corrosive forces of nature are taken into consideration. These forces are constantly in play in the life of every pipe, and are neglected at great peril (Bai, & Bai, 2005 Pipes are also unlike most other forms of infrastructure in that they exist as a diffuse network, and their tendril like manifestations permeate the very fabric of our world. In consideration of the importance of pipes, one group of materials is of particular significance, petroleum. Benefits of pipelines and why are they preferred over other transport systems A common notion of the role that pipes play in modern society, envisions them as benign conduits enabling the flow of useful and pragmatic liquids to a specific location. Despite such a naïve vision, pipelines are also used convey some of the most hazardous liquids in the contemporary world. Modern industry and commerce relies upon the efficiency and relative safety of pipelines to transport their raison d’être. One of the most pervasive forms of pipelines in use in the world today literally fuels the engines of modern industrial capitalism around the globe. These are Petroleum Pipelines. These pipeline networks efficiently transport oil and natural gas throughout their entire life cycle, from their point of exploitation all the way to ultimate consumption. Despite their ubiquitous presence, they are one of the most dangerous forms of infrastructure that exist in the world today. Despite the specter of increased risk, maintenance and inspection duties are still not heavily regulated by public institutions. Private companies initiate their own standards for appraising the integrity of their lines, and implement their own proprietary set of maintenance practices. Because of this, when disaster occurs it seems as though modern energy conglomerates get away with the wanton destruction of local environs (Antak, 2012). Although petroleum pipelines did not immediately emerge at the beginning of the oil industry in the United States, they quickly emerged as the most cost-efficient and safe method to transport petroleum products to sites of production and consumption. Because of its simplicity and efficiency, and “virtually unnoticed by the public, a vast network of pipes was developed between the oil wells and collection points and then between producing areas and refining centers” (Antak, 2012). The speed at which these pipelines emerged near centers of petroleum industry in the United States is directly attributable to the fact that this mode of transportation was significantly more reliable, safe, and inexpensive than prior methods. Much to the delight of its designers, this method of transport also had the ability to become invisible; it could silently and unobtrusively traverse the landscape, carrying with it the life-blood of modern industry. Although many of these pipelines utilized cutting-edge technologies in their implementation and design, by today’s standards they would be considered entirely inadequate and even downright hazardous (Herbich, 2004). Pipeline installation method The reel barges is an offshore pipe lay method is a concept for offshore pipeline and girth welded riser installation which has many advantages compared with traditional installation methods. The method inserts a vertical and a horizontal position to the pipes in which the pipeline is produced, then wound in a flat monolayer spiral floating on the water and finally towed to location to be installed with the help of a simplified lay barge (Chin, 2006). When an S-lay is being performed the pipes are eased down and they curve to form a spiral. This is a limitations of the technology due to the high forces that are needed to build such a floating spiral and to keep it in shape. Furthermore has been put forward that consumption of fatigue resistance for the S welds during storage and transport of the spiral influence the actual fatigue resistance during installation and finally the fatigue life of the pipeline in a way that is unacceptable for the pipeline quality (Bai, & Bai, 2005). The Town in the technology the pipes are suspended by most of the offshore related companies. It non-acceptance has not a technical or economic motivation but rather a strategic one has to do with the enormous change the methodology would have on the offshore pipeline and riser installation industry as a whole and especially the impact it will have on the risk model for these capital intensive companies (Bai, & Bai, n.d.). The method challenges the status quo in the pipeline industry by having a better product, having a lower cost structure, having a faster installation rate and having a safer working environment. Classification Old Corporate Tricks The basic character of pipelines is made to fit the emergence of newer ideologies and standardized operating procedures that have emerged within contemporary petroleum corporations in recent decades. These characterizations address the possible material consequences of pipelines in response to the power of growing environmental conservation concerns (Mohitpour, Golshan, & Murray, 2007). Petroleum companies are thus in support of an ideology which directly correlates a pipelines visibility in the local environment, with the characteristics of a safe and environmentally cognizant piece of infrastructure. By publicly equating a pipelines’ degree of visibility to its capacity for environmentally conservation, companies are further encouraged to hide their pipelines from the critical gaze of a discerning public. Despite its allure, at the crux of this argument lies a terrible fallacy (Palmer & King, 2008). It proclaims that the less a pipeline visually impedes upon a landscape the more unobtrusive its existence is to the local environment. This is then represented as a matter of fact, one that is thoroughly appealing to the governments or members of the local community in direct relation to the pipeline (Chin, 2006). Despite the seductive environmental appeal that burial may impart, it also provides corporations undue power over the health and safety of the local environment through which they run their business. The actions of these companies have a direct effect on the health and survival of the ecosystems that reside in close proximity to their operative infrastructures. The burial (or submergence) of a pipeline both literally (and metaphorically) covers up all that can go wrong in its operation. Without a pipeline’s visibility existing as a key element of its construction pipelines, like the Enbridge No. 5 line, are able to exist for years without any type of enforceable regulatory framework scrutinizing claims about their integrity. In pursuit of ever- increasing profits, petroleum companies utilize a powerful weapon, information. Proper management of public perception, whose concern lies primarily with the environmental safety of such an endeavor, is paramount to the operation’s success. The more morally ambivalent a company is about their responsibility to local communities and their environment, the more capacity such a company has to spread misinformation about their pipeline. Because of the physical invisibility of the pipeline, claims can be made about any aspect of the line question. These claims can rarely be substantiated by anyone other than the operators of the pipeline, to which such details are well known. In this way, energy companies are provided with too much power in their ability to deceive the public and distort the truth about the true effects of their activities. Structural analysis of piping A detailed marine survey is required to enable selection of the pipeline route corridor from the pipe launch way to the location for final pipe positioning. The width of the corridor is a function of the accuracy and tolerance of the positioning system and survey equipment. The planned and actual tow routes must be checked for the presence of any maritime hazards. The seabed along the tow route should preferably be relatively flat and straight, and be free of obstructions such as sharp depressions or elevations, rock out crops, ship wrecks, and subsea structures. Allowable span lengths, and minimum horizontal bending of the pipeline must be calculated as criteria for route selection. The two limiting conditions are considered as being when the pipe is at rest without tension, and moving under tow. To ease the task of a design analysis and route selection, it is feasible to reduce possible variety in types of soils along the route by grouping them into convenient categories. This tactic should still enable acceptable forecasting of the lateral and longitudinal friction coefficients needed for calculation of stability on the seabed and the magnitude of the tow forces. For estimating the conditions when the pipe is static; at the start of towing; and the dynamic case where the pipe is being towed; it is necessary to have a knowledge of the extremes of longitudinal coefficient. Because of continuous variations in the seabed configuration and soils along the tow route, there are corresponding variations in the friction coefficients and dynamic tow forces. For a given type of soil, the starting friction forces are larger than the dynamic friction forces. Tie-in Spools In the coastal shallow sea, the subsea Tie-in Spools are exposed to strong sea wave and current actions on the sea bottom. This results in significant outer lateral and vertical hydrodynamic loading on the pipe. In the same time, inner hydrodynamic loading appears due to fluid flow in bended pipe. All these hydrodynamic loading must be taken into consideration together with the pipe gravity loading and bottom sliding friction to estimate the Tie-in Spools stability and safety on the sea bottom in coastal area. The important detail is the geometry of the sea bottom which differs from the pipe flexural line. Sometimes the sea bottom may have different stiffness along the pipeline trace, especially in the case of bottom soil liquefaction (Chin, 2006). The equilibrium position of the subsea pipeline is calculated by the dynamic FEM model consists of the beam finite elements, representing the pipe structure and shell finite elements, modeling the sea bottom. The special beam element was applied in the model because of large displacement/small strain. The contact problem between the pipe and sea bottom is present in the model and the equilibrium position of the pipeline on the sea bottom had to be calculated in time/space domain by iterative procedure. Installation methods The problem of finding the realistic Tie-in Spools position is modelled as a slow collision between the falling Tie-in Spools structure and sea bottom. It is calculated by the dynamic FEM model consists of beam finite elements, representing the pipe structure and shell finite elements, modeling the sea spring elements in the part where liquefaction is expected. The model is characterized by two strong nonlinearities:large displacement/small deformation of the pipe elements, Boundary contact condition between the pipe and sea bottom equilibrate by sliding friction force between (non-linear interactions). These nonlinearities require the appropriate iteration technique which has to be applied to solve the problem with sufficient accuracy Types of Subsea Tie-in System Vertical Tie-in According to Yong and Qiang, (2005) vertical jumpers are adopted directly onto the U-shaped hub during tie-in. Because the Vertical System does not need a pull-in capability, provides a time efficient tie-in operation, it simplifies the tool functions and reduce the length of Rigid Spools. The actuated half of the connector are placed on the upward jumper. Later the connector are landed on the hubs connected to the subsea equipment. Yong and Qiang further urges that connection and stroking is carried out by the Connector itself. Horizontal Tie-in Systems In Bai & Bai, Subsea pipelines and risers (2005), horizontal Tie-in system can be used for both first end and termination-end system of flow lines, Jumper spools. The termination head is hauled in to the Tie-in point by use of a subsea winch. The spool of horizontal system connected to the beam and lowed few meters above the target area. Yong and Qiang further states that horizontal connections leave the flow line in a straight line, and is easy to protect if over trawling should occur. Reference Antak, G. (2012). Piping and Pipeline Engineering Design, Construction, Maintenance, Integrity, and Repair (1st ed.). Bai, Q., & Bai, Y. Subsea pipeline design, analysis, and installation (1st ed.). Bai, Y., & Bai, Q. (2005). Subsea pipelines and risers (1st ed.). Amsterdam: Elsevier. Chin, W. (2006). Computational rheology for pipeline and annular flow (1st ed.). Norwich, NY: Knovel. Herbich, J. (2004). Offshore pipeline design elements (1st ed.). New York: M. Dekker. Mohitpour, M., Golshan, H., & Murray, A. (2007). Pipeline design & construction (1st ed.). New York: ASME Press. Palmer, A., & King, R. (2008). Subsea pipeline engineering (1st ed.). Tulsa, Okla.: PennWell Corporation. Subsea Pipeline Tie-in. (2017). dwinirestu. 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