Uptake Riser for P-25 Platform in Albacora Field in Campos Basin

Author(s):  
Ricardo Franciss ◽  
Anderson Barata Custódio

The P-25 platform is located at 575 m water depth in Campos Basin, offshore Brazil. In the time of its conversion (1996), its process plant was designed to use cold water streaming from the Antartic continent to cool its equipment, accessories and compressing gas plant for exportation. The uptake riser installed in 1997 is 330 m long, 24″ OD pipe, hanging from the pontoon and the cold water flowing through it enters a sea chest located next to the support. This fully rigid riser was recently asked to be replaced. This paper presents the stages of the reanalysis of this compliant structure under conditions of low cost, so that the platform continues to suck cold water. Because of the presence of the uptake riser, the platform does not have a cooling plant that would else request area and weight, two important items in an arrangement, besides the high cost involved. Within the scope of the analyses, the replacement of the material (originally steel) with offloading hoses is tried out, in search for weight savings and lower cost. These hoses were reinforced with steel cables and their behavior was checked. Some tests were performed to verify the mechanical strength of this material and vibrations by VIV that occur in this structure. Monitoring systems were designed to check all forces and displacements during the referred installation. These actions will consolidate the technology for Petrobras leading to another riser system option for production in ultra deep waters.

Author(s):  
Ricardo Franciss ◽  
Enrique Casaprima Gonzales ◽  
Jose´ Carlos Lima de Almeida ◽  
Jairo Bastos de Arau´jo ◽  
Antonio Carlos Fernandes

Due to the 2200m water depth and harsher environmental conditions, one option that Petrobras is considering for the production of the Pre-Salt fields is the use of a subsurface buoy known as a Buoy Supporting Riser (BSR). It is composed of a subsurface tethered buoy, flexible jumpers connecting the Floating Production Unit (FPU) to the BSR and Steel Catenary Risers (SCRs) connecting the BSR to the flowlines on the sea bottom. The main advantages of this system are that it decouples the FPU motions from the SCRs, reducing fatigue damage in the touch down zone. It may also be installed independently of the FPU, except for the flexible jumpers, which would reduce the risers load on the FPU. Petrobras has been studying this concept since 1997 and has established, as a final stage of the study, a field test with the actual installation of the BSR. This was performed through an alternative method using only Petrobras AHTS boats, in order to avoid critical and expensive resources such as lift barges. With the purpose of validating this new installation procedure, Petrobras performed the referred installation of a 27.2m × 27.2m square ring shaped buoy in Congro Field in the Campos Basin over a water depth of 500m. The buoy was positioned at 80m depth, where the incidence of loads caused by waves is negligible, thus increasing the fatigue life of risers. After the BSR installation, the riser pull-in procedure was also conduced. This paper describes why this technology is necessary for these fields and the model tests made to validate the installation procedures. It also discusses how Petrobras tested the pull-in operations for two flexible risers after the actual buoy was installed. Monitoring systems were designed to check all forces and displacements during the referred installation. These actions will consolidate the BSR technology for Petrobras leading to another riser system option for production in ultra deep waters.


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.


2017 ◽  
Vol 13 (1) ◽  
pp. 17-37 ◽  
Author(s):  
Quentin Dubois-Dauphin ◽  
Paolo Montagna ◽  
Giuseppe Siani ◽  
Eric Douville ◽  
Claudia Wienberg ◽  
...  

Abstract. We present the neodymium isotopic composition (εNd) of mixed planktonic foraminifera species from a sediment core collected at 622 m water depth in the Balearic Sea, as well as εNd of scleractinian cold-water corals (CWC; Madrepora oculata, Lophelia pertusa) retrieved between 280 and 442 m water depth in the Alboran Sea and at 414 m depth in the southern Sardinian continental margin. The aim is to constrain hydrological variations at intermediate depths in the western Mediterranean Sea during the last 20 kyr. Planktonic (Globigerina bulloides) and benthic (Cibicidoides pachyderma) foraminifera from the Balearic Sea were also analyzed for stable oxygen (δ18O) and carbon (δ13C) isotopes. The foraminiferal and coral εNd values from the Balearic and Alboran seas are comparable over the last  ∼  13 kyr, with mean values of −8.94 ± 0.26 (1σ; n =  24) and −8.91 ± 0.18 (1σ; n =  25), respectively. Before 13 ka BP, the foraminiferal εNd values are slightly lower (−9.28 ± 0.15) and tend to reflect higher mixing between intermediate and deep waters, which are characterized by more unradiogenic εNd values. The slight εNd increase after 13 ka BP is associated with a decoupling in the benthic foraminiferal δ13C composition between intermediate and deeper depths, which started at  ∼  16 ka BP. This suggests an earlier stratification of the water masses and a subsequent reduced contribution of unradiogenic εNd from deep waters. The CWC from the Sardinia Channel show a much larger scatter of εNd values, from −8.66 ± 0.30 to −5.99 ± 0.50, and a lower average (−7.31 ± 0.73; n =  19) compared to the CWC and foraminifera from the Alboran and Balearic seas, indicative of intermediate waters sourced from the Levantine basin. At the time of sapropel S1 deposition (10.2 to 6.4 ka), the εNd values of the Sardinian CWC become more unradiogenic (−8.38 ± 0.47; n =  3 at  ∼  8.7 ka BP), suggesting a significant contribution of intermediate waters originated from the western basin. We propose that western Mediterranean intermediate waters replaced the Levantine Intermediate Water (LIW), and thus there was a strong reduction of the LIW during the mid-sapropel ( ∼  8.7 ka BP). This observation supports a notable change of Mediterranean circulation pattern centered on sapropel S1 that needs further investigation to be confirmed.


Author(s):  
Murat Fidan ◽  
Alper Bayrak ◽  
Umid Karli

In this study, a low-cost and adaptable isometric strength measurement and exercise development system are described. The implemented system consists of mechanical structure, force measurement sensor, electronic circuit, and computer software. Isometric-isotonic (via spring resistance) strength analysis and various exercise programs can be applied with the system. The developed system has a lower cost compared to its counterparts in the literature and has a structure that can be adapted to different machines and measuring methods. The operability and reliability of the isometric strength measurement and exercise development system have been proven by calibration tests.


Sensors ◽  
2021 ◽  
Vol 21 (9) ◽  
pp. 3056
Author(s):  
Baiqian Shi ◽  
Stephen Catsamas ◽  
Peter Kolotelo ◽  
Miao Wang ◽  
Anna Lintern ◽  
...  

High-resolution data collection of the urban stormwater network is crucial for future asset management and illicit discharge detection, but often too expensive as sensors and ongoing frequent maintenance works are not affordable. We developed an integrated water depth, electrical conductivity (EC), and temperature sensor that is inexpensive (USD 25), low power, and easily implemented in urban drainage networks. Our low-cost sensor reliably measures the rate-of-change of water level without any re-calibration by comparing with industry-standard instruments such as HACH and HORIBA’s probes. To overcome the observed drift of level sensors, we developed an automated re-calibration approach, which significantly improved its accuracy. For applications like monitoring stormwater drains, such an approach will make higher-resolution sensing feasible from the budget control considerations, since the regular sensor re-calibration will no longer be required. For other applications like monitoring wetlands or wastewater networks, a manual re-calibration every two weeks is required to limit the sensor’s inaccuracies to ±10 mm. Apart from only being used as a calibrator for the level sensor, the conductivity sensor in this study adequately monitored EC between 0 and 10 mS/cm with a 17% relative uncertainty, which is sufficient for stormwater monitoring, especially for real-time detection of poor stormwater quality inputs. Overall, our proposed sensor can be rapidly and densely deployed in the urban drainage network for revolutionised high-density monitoring that cannot be achieved before with high-end loggers and sensors.


Author(s):  
Marcos Donato Ferreira ◽  
Mauro Costa de Oliveira ◽  
Rafaella Cristina Carvalho ◽  
Sergio Hamilton Sphaier

In the development of the mooring design of FPSOs in spread mooring system (SMS) configuration, it was observed that the utilization of asymmetric riser arrangement in deep waters might lead to an asymmetrical roll response of the FPSO. In particular, concentrating all riser connections on the portside, it could be observed that roll and heave coupling under the influence of the riser dynamics might lead to a much lower roll response associated with waves coming from portside than from the starboard direction. Simulations were carried using an in-house time domain simulator, where the ship hydrodynamic behavior was represented through the use of impulse response functions and the lines dynamic through the use of non-linear finite element method, using an explicit integration scheme and a lumped mass approach. Non-linear viscous effects could be easily associated to the ship and line velocities. Measured motion responses of an actual FPSO in operation in Campos Basin are compared with the computations.


2005 ◽  
Vol 48 (spe) ◽  
pp. 135-142 ◽  
Author(s):  
Adriano Aguiar Mendes ◽  
Heizir Ferreira de Castro

The objective of this work was to evaluate the replacement of Gum Arabic for sodium chloride to reduce fat and organic contents in dairy wastewater using two low cost commercially available lipase preparations from animal source (Kin Master - LKM and Nuclear- LNU). The best performance was achieved when lipase Nuclear (LNU) was used as catalyst. In addition, this lipase preparation has also lower cost, which makes its use a quite promising technique for reduction of suspended solids as proteins and lipids contents found in wastewater generated by dairy industries.


2012 ◽  
Vol 459 ◽  
pp. 544-548 ◽  
Author(s):  
Wei Liang ◽  
Jian Bo Xu ◽  
Wei Hong Huang ◽  
Li Peng

Network security technology ensures secure data transmission in network. Meanwhile, it brings extra overhead of security system in terms of cost and performance, which seriously affects the rapid development of existing high-speed encryption systems. The existing encryption technology cannot meet the demand of high security, low cost and high real-time. For solving above problems, an ECC encryption engine architecture based on scalable public key cipher and a high-speed configurable multiplication algorithm are designed. The algorithm was tested on FPGA platform and the experiment results show that the system has better computation speed and lower cost overhead. By comparing with other systems, our system has benefits in terms of hardware overhead and encryption time ratio


Author(s):  
Jairo Bastos de Araujo ◽  
Roge´rio Diniz Machado ◽  
Cipriano Jose de Medeiros Junior

Petrobras developed a new kind of anchoring device known as Torpedo. This is a steel pile of appropriate weight and shape that is launched in a free fall procedure to be used as fixed anchoring point by any type of floating unit. There are two Torpedoes, T-43 and T-98 weighing 43 and 98 metric tons respectively. On October 2002 T-43 was tested offshore Brazil in Campos Basin. The successful results approved and certified by Bureau Veritas, and the need for a feasible anchoring system for new Petrobras Units in deep water fields of Campos Basin led to the development of a Torpedo with High Holding Power. Petrobras FPSO P-50, a VLCC that is being converted with a spread-mooring configuration will be installed in Albacora Leste field in the second semester of 2004. Its mooring analysis showed that the required holding power for the mooring system would be very high. Drag embedment anchors option would require four big Anchor Handling Vessels for anchor tensioning operations at 1400 m water depth. For this purpose T-98 was designed and its field tests were completed in April 2003. This paper discusses T-98 design, building, tests and ABS certification for FPSO P-50.


2008 ◽  
Vol 59 ◽  
pp. 101-107 ◽  
Author(s):  
Rodinei Medeiros Gomes ◽  
Ana Cris R. Veloso ◽  
V.T.L. Buono ◽  
Severino Jackson Guedes de Lima ◽  
Tadeu Antonio de Azevedo Melo

Polycrystalline copper-based shape memory alloys have been of particular interest in relation to Ni-Ti because of their low cost and good shape memory effect. Nevertheless the absence of a pronounced pseudoelasticity effect restricts the number of potential applications. In this work, the influence of Nb and V on the microstructure and the mechanical properties was investigated. Samples of Cu-13.8 Al-Ni containing V and Nb alloy were prepared by induction and solution treated at 850°C and then further quenched into cold water. The addition of Nb and V promotes the formation of precipitates which act as grain refiner and subsequently improve the mechanical properties. The tensile tests were performed at temperatures slightly inferior to Mf and superior to Af, to investigate the shape recovery and pseudoelasticity, respectively. Based on the analyses of the Cu-13,8Al-2Ni-1Nb (wt%) alloy was detected rupture strains greater than 14%, besides observation of the superelasticity of these alloys and quantification of this property by means of cycling, from 0 to strains between 1 and 7%. The studies performed on alloy Cu-13.8Al- 3,5Ni-1V (wt%) made it possible to determine rupture strains in the order of 3% and its superelastic behavior through cycling for deformations between 1 and 3%.


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