The Roncador P52 Oil Export System - Hybrid Riser at a 1800m Water Depth

Author(s):  
Francisco Edward Roveri ◽  
Adolfo Guilherme Velten Filho ◽  
Vinicius Costa Mello ◽  
Luciano Faria Marques
Keyword(s):  
Author(s):  
Ken M. Topolinsky ◽  
German D. Ordoñez R.

Shipments began in October 1997 along Oleoducto Central S.A (OCENSA), the 837 km oil export system, consisting of 406, 762 and 914 mm (16”, 30” and 36”) diameter pipe, from eastern Colombia to the country’s north coast on the Carribean Sea. Start-up follows the completion of a phased construction program which began in 1993–94 and ended in September 1997. The system transports production from the Cusiana / Cupiagua oilfields, and several adjacent smaller production fields in the eastern foothills of the Andes to an offshore terminal loading unit 11 km offshore. The authors provide an operating overview of this system designed to handle some 88,410 m3/d (556 kbd) and some of its operating challenges.


Author(s):  
Jim Brooks ◽  
Craig Masson ◽  
David Reeves

Suspended from the Atlantis Production Quarters Semi-submersible in over 7000 ft water depth, the 24-inch diameter Mardi Gras Oil Export Steel Catenary Riser (SCR) presented many challenges for design and installation. In particular the touchdown region of the riser was subject to severe fatigue and extreme loadings. The Engineering Critical Assessment (ECA) at the weld OD generated defect acceptance criteria that would be impractical to apply with the available inspection technology. To mitigate this, the decision was made to remove the weld caps in the most critical portion of the SCR. This paper describes the design drivers that led to this decision and the steps taken to ensure successful implementation.


Author(s):  
Ricardo Franciss ◽  
Elton Ribeiro

Petrobras is going deeper and some fields are feasible only if the production platforms are installed in ultra deep waters, close to the wells. In one case in Campos Basin, for example, the platform will be installed at 1255 m water depth and the solution to allow the production is based on the evolution of flexible lines for high pressure and high loads. For the oil export line, however, a steel rigid line was chosen, due to the large diameter. Some analyses were performed in order to make it feasible the installation of an 18-inch SCR export oil line. Due to fatigue loads, the free hanging catenary configuration did not match with API RP 2RD recommendations, so Petrobras decided to change the original shape to Lazy Wave in order to reduce the top loads and increase the fatigue life. But, some configurations are not feasible to install. High angles close to the installation vessel or high stresses close to the flotation segments are some problems that must be solved. This article will present the steps made to reach a configuration that will make feasible the installation of this riser, in parallel to the static and dynamic analysis, to maintain the stresses in an allowable level, in accordance with API RP 2RD.


Author(s):  
Basim B. Mekha ◽  
Enda O’Sullivan ◽  
Andre Nogueira

The Marco Polo TLP, located in Green Canyon Block 608 in 4300 ft water depth exports oil and gas through 12-inch oil and 18-inch gas export SCRs that are connected to Marco Polo 14-inch oil and 18inch/20-inch gas export pipelines. Following completion of the installation of the 14-inch oil export pipeline and during the installation of the 12-inch oil export SCR on the seabed (with about 3,000 ft or 77 SCR pipe joints still to go), the operation had to be abandoned due to bad weather and the SCR pipe lowered to the seabed. During the abandonment operation, a high tension event occurred, causing the transition joint between the 14-inch and 12-inch pipes to slide by about 820 ft toward the TLP. This would have the effect of changing the touchdown position along the SCR and consequently the Three Layer Polyethylene abrasion coating would not be located at the at the touchdown to perform its function. In order to move the SCR touchdown area at least partially to the TLPE region, it was decided that four extra joints would be welded to the SCR resulting in the SCR departure angle to changing from 12 degrees to 10 degrees. This paper presents the methodology used for the original design of the oil export SCR and the design robustness, flexibility and margins that allowed for the design to be modified in the last minutes without compromising the integrity of the SCR. The paper also discuss the steps taken to ensure that the modified design is acceptable and within the code requirements. Some strength and fatigue results are presented.


Significance The announcement comes after the feasibility study by Toyota Tsusho reportedly concluded that a cross-border oil export pipeline appears economically viable, favouring Lamu as the final destination. However, low oil prices, a slowed exploration rate in Kenya and political barriers raise questions on how development of the region's oil finds can be made economically sound for the companies involved. Impacts South Sudan's inclusion in a regional export system is likely to be suspended until conflict subsides. Production of its higher quality Nile Blend oil from Unity State fields will remain shut for the foreseeable future. The fixed per barrel rate to Sudan, including extra to compensate for the loss of fields after secession, will be renegotiated in 2016.


2020 ◽  
Vol 14 (3) ◽  
pp. 7082-7093
Author(s):  
Jahirwan Ut Jasron ◽  
Sudjito Soeparmani ◽  
Lilis Yuliati ◽  
Djarot B. Darmadi

The hydrodynamic performance of oscillating water column (OWC) depends on the depth of the water, the size of the water column and its arrangement, which affects the oscillation of the water surface in the column. An experimental method was conducted by testing 4 water depths with wave periods of 1-3 s. All data recorded by the sensor is then processed and presented in graphical form. The research focused on analyzing the difference in wave power absorption capabilities of the three geometric types of OWC based on arrangements of water columns. The OWC devices designed as single water column, the double water column in a series arrangement which was perpendicular to the direction of wave propagation, and double water column in which the arrangement of columns was parallel to the direction of wave propagation. This paper discussed several factors affecting the amount of power absorbed by the device. The factors are the ratio of water depth in its relation to wavelength (kh) and the inlet openings ratio (c/h) of the devices. The test results show that if the water depth increases in the range of kh 0.7 to 0.9, then the performance of the double chamber oscillating water column (DCOWC) device is better than the single chamber oscillating water column (SCOWC) device with maximum efficiency for the parallel arrangement 22,4%, series arrangement 20.8% and single column 20.7%. However, when referring to c/h, the maximum energy absorption efficiency for a single column is 27.7%, double column series arrangement is 23.2%, and double column parallel arrangement is 29.5%. Based on the results of the analysis, DCOWC devices in parallel arrangement showed the ability to absorb better wave power in a broader range of wave frequencies. The best wave of power absorption in the three testing models occurred in the wave period T = 1.3 seconds.


10.29007/zx1w ◽  
2018 ◽  
Author(s):  
Dung Tien Tran ◽  
Anh Tuan Le ◽  
Hong Nhung Le ◽  
Viet Hung Ho

A study of average flow in open channel with baffle blocks distributed uniformly has been considered by using channel with varied slopes. In this article, experimental and modelling studies were introduced when the correlation between the water depth and baffle block size is significant. The objective of the work is to give the rudimentary relations between discharge and water level in the channels. When the water depth is large, the effect of bottom channel friction on the flow is relatively small. This paper also gives applications of the software ‘Telemac-2D’ to simulate the flow under different conditions.


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