936 resultados para Petroleum pipelines
Resumo:
There are different methods of construction of outfall pipelines, all of them have to solve the problem of placing a tube over a known location in sea bed. This process has sometimes to be done in difficult conditions as waves, current or depths greater than 30 metres, where a diver cannot go safely beyond. Also the placement of the pipeline must be carried out without any damage to the tube, therefore a close control of the deflections and stresses in the structure must be performed. The importance of this control should be not diminished because a damage during the construction would imply a very difficult and expensive repair, that should be avoided with a proper design of the construction process. This paper is focused in the analysis of the tube during its placement according to a very well known construction method consisting in placing the tube from a boat, where all the connections between consecutive tube segments are performed, and also the whole process is controlled. This method is used for outfall as well as offshore pipelines, and it will be described in Section 2
Resumo:
O transporte de gás e derivados de petróleo é realizado pelo uso de tubulações, denominadas de oleodutos ou gasodutos, que necessitam de elevados níveis de resistência mecânica e corrosão, aliadas a uma boa tenacidade à fratura e resistência à fadiga. A adição de elementos de liga nesses aços, Ti, V e Nb entre outros, é realizada para o atendimento destes níveis de resistência após o processamento termomecânico das chapas para fabricação destes dutos, utilizando-se a norma API 5L do American Petroleum Institute, API, para a classificação destes aços. A adição de elementos de liga em associação com o processamento termomecânico visa o refino de grão da microestrutura austenítica, o qual é transferido para a estrutura ferrítica resultante. O Brasil é o detentor das maiores reservas mundiais de nióbio, que tem sido apresentado como refinador da microestrutura mais eficiente que outros elementos, como o V e Ti. Neste trabalho dois aços, denominados Normal e Alto Nb foram estudados. A norma API propõe que a soma das concentrações de Nióbio, Vanádio e Titânio devem ser menores que 0,15% no aço. As concentrações no aço contendo mais alto Nb é de 0,107%, contra 0,082% do aço de composição normal, ou seja, ambos atendem o valor especificado pela norma API. Entretanto, os aços são destinados ao uso em dutovias pela PETROBRÁS que impõe limites nos elementos microligantes para os aços aplicados em dutovias. Deste modo estudos foram desenvolvidos para verificar se os parâmetros de resistência à tração, ductilidade, tenacidade ao impacto e resistência à propagação de trinca por fadiga, estariam em acordo com a norma API 5L grau X70 e com os resultados que outros pesquisadores têm encontrado para aços dessa classe. Ainda, como para a formação de uma dutovia os tubos são unidos uns aos outros por processo de soldagem (circunferencial), o estudo de fadiga foi estendido para as regiões da solda e zona termicamente afetada (ZTA). Como conclusão final observa-se que o aço API 5L X70 com Nb modificado, produzido conforme processo desenvolvido pela ArcelorMittal - Tubarão, apresenta os parâmetros de resistência e ductilidade em tração, resistência ao impacto e resistência a propagação de trinca em fadiga (PTF) similar aos aços API 5L X70 com teores de Nb = 0,06 % peso e aqueles da literatura com teores de Nb+Ti+V < 0,15% peso. O metal base, metal de solda e zona termicamente afetada apresentaram curvas da/dN x ΔK similares, com os parâmetros do material C e m, da equação de Paris, respectivamente na faixa de 3,3 - 4,2 e 1.3x10-10 - 5.0x10-10 [(mm/ciclo)/(MPa.m1/2)m].
Resumo:
The UCM Instrumentation Group (GUAIX) is developing currently Data Reduction Pipelines (DRP) for four instruments of the GTC: EMIR, FRIDA, MEGARA and MIRADAS. The purpose of the DRPs is to provide astronomers scientific quality data, removing instrumental biases, calibrating the images in physical units and providing a estimation of the associated uncertainties.
Resumo:
"The pr1.mary purpose of this thea1a waa to learn about and t .o produce a aeries of pa1nt1n~.a that aymbolized. tbe oil induatry 1n Lea. Count,-, New ltexic.o. The secondary purpose waa to learn more about tho oil industry, which is the big business in Le.a Countj, :New Mexico"
Resumo:
Construction companies are interested in adopting environmental methods, such as in situ bioremediation, when conducting remediation at petroleum contaminated sites. This interest is due to both the cost benefits associated with in situ bioremediation methods and the environmental movement. This project creates a comprehensive manual comprised of information about site investigations, treatability studies, design, and implementation of in situ bioremediation at petroleum contaminated sites. The training manual also provides information about regulatory requirements and permitting for petroleum contaminated sites.
Resumo:
This paper deals with the stabilisation of low softening point pitch fibres obtained from petroleum pitches using HNO3 as oxidising agent. This method presents some advantages compared with conventional methods: pitches with low softening point (SP) can be used to prepare carbon fibres (CF), the stabilisation time has been reduced, the CF yields are similar to those obtained after general methods of stabilisation, and the initial treatments to increase SP when low SP pitches are used to prepare CF, are avoided. The parent pitches were characterised by different techniques such as diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS), elemental analysis and solvent extraction with toluene and quinoline. The interaction between HNO3 and the pitch fibres, as well as the changes occurring during the heat treatment, have been followed by DRIFTS.
Resumo:
Results show that it is possible to activate a low softening point isotropic petroleum pitch, without intermediate pre-treatments, by chemical activation with KOH. The chemical activation is carried out by direct heat treatment of a mixture of the isotropic pitch and KOH. It produces activated carbons (ACs) with micropore volumes as high as 1.12 cm3/g, and BET surface areas around 3000 m2/g. The activating agent/precursor ratios studied (from 1/1 to 4/1; wt./wt.) show, as expected, that increasing the ratio enhances the adsorption characteristics of the resulting AC.
Resumo:
A method using iodine has been developed for the stabilisation of low softening point (SP) pitch fibres that avoids air stabilisation in the production of carbon fibres (CF). The interaction between iodine and petroleum pitches has been studied by following the changes in the hydrogen content, aromatic or aliphatic, during the heat treatment of iodine-treated pitch fibres. Two low SP petroleum pitches were used and the iodine-treated pitch fibres were analysed by TGA, DSC, DRIFT, XPS and SEM. The results confirm that using this novel method pitches with low SP can be used to prepare CF with two advantages, compared with conventional methods. The stabilisation time is considerably reduced and treatments to increase the SP, usually required when low SP pitches are used to prepare CF, can be avoided.
Resumo:
The paper provides interesting evidences that a low softening point isotropic petroleum pitch can be used as a good carbon precursor for the preparation of activated carbons. The activation is carried out by KOH and/or NaOH and the resulting activated carbons present well developed porosity. Such hydroxide activations can be done directly on the pristine petroleum pitch (P) or on the pitch that has been submitted to an air stabilisation followed by a N2 heat treatment (TAN). In general, KOH activation produces better results than NaOH, both in terms of porosity and yield, the results obtained for the activation of TAN being impressive because of the good porosity developments and high yields reached. The different treatments carried out over the petroleum pitch precursor clearly show that they significantly influence the extent of microporosity development. This is due to different changes occurring in the porous structure of the precursor as a function of the treatment carried out. The efficiency of the activation process increases as the mesophase content of the precursor decreases, as well as the mesophase formation during the activation process is avoided.