scholarly journals OPTIMUM DESIGN OF HIGH-PRESSURE, LARGE-DIAMETER, DIRECT-NUCLEAR-PUMPED, GAS LASERS

1965 ◽  
Author(s):  
J.A. Jr. DeShong
2021 ◽  
Vol 73 (03) ◽  
pp. 60-61
Author(s):  
Judy Feder

This article, written by JPT Technology Editor Judy Feder, contains highlights of paper OTC 30558, “Development and Implementation of Heavy-Wall, High-Strength, Sour-Service Accessory and Risers for HP/HT Application in the Gulf of Mexico,” by Carine Landier, Jonathas Oliveira, and Christelle Gomes, Vallourec, et al., prepared for the 2020 Offshore Technology Conference, originally scheduled to be held in Houston, 4–7 May. The paper has not been peer reviewed. Copyright 2020 Offshore Technology Conference. Reproduced by permission. As oil and gas development in the Gulf of Mexico increasingly requires high-pressure/high-temperature (HP/HT) applications, the need for sour-service (SS) resistance also has grown. To meet these needs, continual innovation and improvement is needed in SS-grade materials from a technical and cost-effectiveness perspective. The complete paper discusses the material properties achieved with several large-diameter, heavy-wall SS pipes. The complete paper presents a detailed, illustrated discussion of the applications for the high-strength SS pipe and its manufacturing process. Applications The authors write that improved materials to meet HP/HT requirements such as those in the Gulf of Mexico are needed particularly for two applications: for risers, which require high-strength, thick-wall sour service; and as a substitute for corrosion-resistant alloy (CRA) with sour carbon material on defined accessories. Vallourec has developed high-strength [125,000-psi specified minimum yield strength (SMYS)] and resistant carbon steel pipes in sizes with outer diameter (OD) up to 23 in. and wall thickness up to 2.5 in. These sizes are common in lower-strength material, but meeting the high-pressure requirements with higher-grade material enables cost savings and eliminates some CRA components. It also enables the use of much-lighter-weight pipe than the 80,000-psi SMYS material that is standard for SS applications in oversize OD and heavy wall. Risers. Most deepwater drilling is performed with classic subsea blowout-preventer (BOP) systems. Access to the well through the BOP is accomplished with low-pressure, large-diameter (19-in. internal diameter) drilling riser pipe. Pipes are supplied in weldable grades (API 5L X65–X80). Large-diameter forged flanges are then welded onto the tubes. Connections are made by multiple bolts. High pressures, required as part of the drilling process, are supplied by small-diameter choke-and-kill lines. This system has served the industry well, but, as well pressures increase, so have cost and feasibility requirements of subsea BOP technology. These costs, driven by the complexity of redundant systems, have driven a desire to explore an alternative solution—a surface BOP with high-pressure drilling riser pipe. Using a surface BOP reduces the complexity and cost of the system significantly because of the ability to inspect it. The drilling riser then carries the pressure to the surface and must be able to contain it. The high-pressure environment that instigated a new solution was based on a 15,000-psi well pressure with NACE Region 2 SS performance. Because of the requirement for weldable grades for attaching the flange as well as SS, the maximum yield strength has been limited to 80,000 psi. At that strength, a very high wall thickness is required to meet 15,000 psi and greater. This becomes very heavy and can be limited by the rig hook-load capacity. Alternatives in weldable grades are nickel-based alloys with SS performance. A full string, however, is prohibitively expensive.


1975 ◽  
Vol 11 (9) ◽  
pp. 881-881 ◽  
Author(s):  
V. Danilychev
Keyword(s):  

Author(s):  
Joe Zhou ◽  
Brian Rothwell ◽  
Wenxing Zhou ◽  
Maher Nessim

Two example onshore gas pipelines were designed using a reliability-based approach. The first example (1219 mm, 17.2 MPa) represents a high-pressure large-diameter pipeline; the second example has a smaller diameter (762 mm) and lower pressure (9.9 MPa). Three steel grades (X70, X80 and X100) were used to develop three design solutions for each example. The wall thickness-related life cycle costs of the designs were evaluated. The design outcomes show that the reliability targets for both examples can be met using X100 steels and high equivalent design factors (0.93 for the first example and 0.9 for the second example). Moreover, ruptures and excessive plastic deformation of a defect free pipe were found to be insignificant integrity threats even when the design uses X100 and relatively high equivalent design factors such as 0.85 and 0.9. The economic assessment results show that the X100 design is the most economical option for the high-pressure large-diameter example. However, using X100 does not show a clear economic advantage over using X80 for the second example mainly because the wall thickness for the design using X100 is governed by the maximum D/t ratio constraint. The study also demonstrates the advantages of the reliability-based approach as a valuable tool in assessing the feasibility and potential benefits of using high-grade steels on a pipeline project.


2007 ◽  
Vol 2007.6 (0) ◽  
pp. 329-330
Author(s):  
Kohta HARIYA ◽  
Sergey DMITRIEV ◽  
Nobuhiro YOSHIKAWA

Author(s):  
Hamid Jahed ◽  
Behrooz Farshi ◽  
Morvarid Karimi

Multi-layered pressure vessels are widely used in the field of high pressure technology. To enhance their load bearing capacity and life, different beneficial processes such as shrink-fit and autofrettage are usually employed. Shrink-fit process, increases load capacity but maximum interference is generally limited. Autofrettage, makes steep stress gradients moving away from bore but Bauschinger effect limits maximum feasible compression level. A combination of both, can conceivably give better stress distribution in layered vessels. The optimum design of a three-layer vessel for maximum life expectancy has been considered here, under the combined effects of autofrettage and shrink-fit. The numerical optimization procedure known as the Simplex search method is employed to get the optimum design. The layer thicknesses, shrink-fit pressures, and autofrettage percentages are treated as design variables. Under stress constraints, the operational sequences of the above processes, for assembly of the layered vessel have also been formulated so as to lead to best results. The fatigue life consideration is based on ASME code and standard for high pressure vessel technology defining the allowable final crack depth in multi-layered vessels. The proposed procedure is carried out on a number of examples. The results show that significant life enhancement can be achieved using the optimization procedure with proper combination of operations.


2013 ◽  
Vol 734-737 ◽  
pp. 892-897
Author(s):  
Jian Jun Cao ◽  
Yong Jiang Zhang ◽  
Zun Yu Xu ◽  
Ben Qing Yuan

The effect of gas extraction would be significantly increased by the way of coal section drilling hole diameter expansion. For the existing technical problems and limitating of constructing large diameter borehole directly or using the reaming way of SKP high pressure water jet, and based on heterogeneous crushing mechanism of high pressure water jet, the integrative hydraulic drilling and reaming completely technology is proposed, the system structure of the technology is researched, the main equipments are integrative selected, and the process characteristics and application prospect of the technology are concluded. The results show that the integration technology of the integrative hydraulic drilling and reaming obvious improves the permeability of coal, promotes gas release, realizes continuous drilling between coal and seam and carried out simultaneously with drilling and reaming. It could significantly increase reaming efficiency and adaptability of evil working condition, which has important popularized and applied values.


Author(s):  
G. Demofonti ◽  
G. Mannucci ◽  
L. Barsanti ◽  
C. M. Spinelli ◽  
H. G. Hillenbrand

Actually, the increase in natural gas needs in the European market, foreseen for the beginning of the next century, compels to develop new solutions for the exploitation of gas fields in remote areas. For natural gas transportation over long distances the hypothesis of a large diameter high-pressure pipeline, up to 150 bar (doubling of the actual one) has been found economically attractive, resulting in significant reduction of the transportation cost of the hydrocarbon. In this contest the interest amongst gas companies in the possible applications of high-grade steels (up to API X100) is growing. A research program, partially financed by E.C.S.C. (European Community for Coal and Steel), by a joint co-operation among Centro Sviluppo Materiali (CSM), S.N.A.M. and Europipe in order to investigate the fracture behaviour of large diameter, API X100 grade pipes at very high pressure (up to 150 bar) has been carried out. This paper presents: the current status of technology of API X100 steel with respect to the combination of chemical composition, rolling variables and mechanical properties the results obtained from West Jefferson tests, in order to confirm the ductile-brittle transition behaviour stated from laboratory tests (DWTT), the results obtained concerning the control of long shear propagating fracture and in particular the results of a full scale crack propagation test on line operating at very high hoop stress (470 MPa). Besides, in order to investigate the defect tolerance behaviour of the pipe with respect to axial surface defect, burst tests with water as pressurising medium have been carried out and the relative results are presented and discussed.


Sign in / Sign up

Export Citation Format

Share Document