Operating in remote regions, Russian pipelines not only are subjected to harsh environmental conditions, but also in some of their sections to seismic activity. In order to secure these assets’ integrity, monitoring is mandatory. Due to the long distances to be monitored and to the linear nature of these pipelines, distributed fiber optic sensing is the only solution to provide remote monitoring operation with accurate localization of events. In some cases, it can even take advantage of the telecommunication fibers laid along the pipelines to minimize installation cost. A complete and commercially available solution based on the DITEST Asset Integrity Monitoring (AIM) system combines strain and temperature measurement over 100’s kilometers at meter spatial resolution with dedicated fiber optic cables specifically developed for strain, temperature and ground movement measurement to provide continuous information on any abnormal pipeline behavior, including leak, intrusion, excessive tube deformation and seismic activity. This scalable monitoring solution was adopted to monitor the most critical areas of the Sakhalin-Khabarovsk-Vladivostok pipeline route, which crosses 32 Active Tectonic Faults (ATF) zones. A combination of pipeline deformation monitoring, ground movement detection and leak detection is used to monitor these critical pipeline regions. The early knowledge of abnormal events allows the pipeline owner/operator to take preventive mitigation measures in response to these critical geohazards.
In this study, we look at recent developments in our understanding of the life cycle of the red spiny lobster Panulirus argus (Latreille, 1804) and examine the evidence for connectivity between geographical regions, especially the north-northeast Brazilian continental shelf and the Wider Caribbean. The study also covers aspects of reproduction, phyllosoma density, large-scale oceanic circulation, self-recruitment, settlement patterns, ecological behaviour, and the impact of the Amazon and Orinoco river discharge on recruitment. Our findings support the hypothesis that lobster larvae are transported by ocean currents and free eddies from Brazil to the Caribbean via the Lesser Antilles, outlining a south-to-north connectivity. In addition, we look into the probable existence of hybrids between sympatric lobster species, as evidenced by differences in colour patterns and morphology.
Estimates of spiny lobster stocks (Panulirus argus Latreille, 1804) represent a fundamental input for population assessment models and are, therefore, indispensable for proper management. In this study we analysed methodologies employed in the Gulf of Batabanó (Cuba) and Providencia and Santa Catalina (Colombian Caribbean) to estimate abundance (N) and stock productivity. We found evidence that the relative abundance (CPUE) for trap-like jaulones and skin diving in natural shelters was likely to remain high despite the decline in abundance (hyperstability). In contrast, the proportionality between CPUE and N was satisfactory in artificial shelters (Cuban pesqueros). Stock productivity was greater for jaulones (22 288 kg/km2) than for pesqueros (1309 kg/km2) or natural shelters (15.25 kg/km2), reflecting differences in the productive capacity of each type of fishing gear. In natural shelters the exploitable biomass is under great fishing pressure and the reproductive stock is likely to decrease. Thus, the West zone of Providencia and Santa Catalina, characterized by high-density seagrass and mangrove, should be designated a marine protection area to prevent a lobster fishing collapse. The most effective measure to revert the lobster fishing collapse in Cuba would be to ban the use of jaulones and liftable pesqueros, thereby reducing fishing intensity.
The present work introduces the technology background at the origin of FOPIMS (Fiber Optic Pipeline Integrity Monitoring Systems) with an emphasis on geotechnical monitoring. It shows how temperature sensing can be implemented to control soil erosion or dune migration through event localization and spatial quantification. Arctic pipeline monitoring project illustrates the application of soil erosion detection. Direct measurement of strain in soil also enhances environmental threat detection. Combined with temperature sensing, strain sensing composes the geotechnical monitoring system. Transandean pipeline monitoring examples are presented where the DITEST AIM was implemented for geohazard prevention. These study cases concern new pipeline installation as well as retrofit of existing lines. The technique successfully evidenced early events and allowed preventive measures to be taken. In some applications actual pipeline deformation need to be monitored. Such operation is achieved by measuring distributed strain along sensing cables attached to the structure. We show how such measurements complement the geotechnical measurements. We also describe a real implementation in seismic active area. As a whole, the work focuses on the technique principles, the installation and how the system is being implemented for pipeline preventive maintenance. We intend to present a comprehensive set of design guidelines based on real results and lessons learned from the various projects in what concerns geohazard detection and pipeline deformation monitoring.
The Amazonian tortoise, Geochelone denticulata, has been classified as vulnerable; nevertheless, necessary ecological and demographic information to formulate conservation plans is limited. In this study we present data on population density, habitat preference, diet and morphological measurements of a population inhabiting a lowland rainforest in Colombia. We used line transect methods to estimate population density over three different years, and we measured and marked 73 individuals in two additional years. The estimated population density based on 158 encounters was similar over the three years (41 ± 20, 38 ± 6, 34 ± 8 ind/km 2 ±SE, respectively). However, we found marked differences between seasons within years, because it was easy to detect individuals (particularly males) during mating periods. There was no evidence of large scale seasonal migrations; thus, it is possible that individuals were missed in the non-reproductive season and therefore our figures may underestimate population size. For the same reason, sex ratios during the mating season may be more biased towards males than for whole year estimates (1.7:1 vs. 1.2:1). Monthly density estimates were significantly correlated with mating frequency and with estimates of fruit abundance, but were not associated with rainfall, temperature or sun radiance. These results suggest that males might use available energy from fruit to travel extensively during the mating season in search of females. However, the most productive forest type in terms of fruit was not preferred by tortoises, to the contrary, they were more commonly encountered in forests with a high proportion of gaps. Males tended to have larger and more elongated bodies than females. This result supports the hypothesis that since males must travel more in search of mates, it is an advantage for them to have an elongated carapace in order to move through dense understory. More ecological information is required from other geographical locations to establish which ecological variables are most important in determining the carrying capacity for terrestrial tortoises. So far the demographic structure of the populations suggest that predation of young individuals plays a major role.
The paper describes first the laboratory and qualifications works that were conducted to implement Distributed Fiber Optic Sensors (DOFS) such as Distributed Temperature and Strain Sensing (DTS/DSS) technologies in umbilicals. It also shows how these technologies have been implemented in the field for umbilical thermal and mechanical stresses monitoring. There is value to use DFOS for offshore structure integrity monitoring such as flow lines, risers and umbilicals. Other applications such as rating of power umbilicals, flow assurance or downhole sensing would help optimize field production as well.Currently, the offshore full scale implementation of DFOS technologies still faces challenges of its own. In particular, sensor integration into the structure to be monitored is a minimum requirement which applies to any DFOS. If fiber optic is a common mean of data transmission, subsea conditions imply the use of specific components such as Wet Mate Connectors (WMC) and Fiber Optic Rotary Joints (FORJ). These components present large insertion and return loss characteristics which are detrimental to most of the DFOS. The effect of these components is twofold. First it impacts the sensor optical budget limiting its measurement range. Second, sensor sections remain completely blind due to the high reflection levels leaving the structure without status information over distances that can be as large as several kilometers.The present works describes how DTS/DSS based on Stimulated Brillouin Scattering (SBS) can overcome the limitations imposed by both WMC and FORJ. The DOFS ability is justified theoretically and demonstrated experimentally through qualification trials involving hotspot detection while WMC and FORJ are part of the sensor path. Their effects are quantified through the determination of the measurement dead zone (shorter than 4m), the temperature uncertainty (better than 0.5K) and the resolution (below 0.5K while the measurement time remained unchanged (tens of seconds to minutes). The work also reports the subsequent installation on operational structures as these trials were successful. The DOFS has been installed to continuously monitor the temperature of a 3km long power umbilical and control the heating system of subsea rigid flowlines whose length can be as large a 45km.
The concern of the pipeline industry and general population for a safe and green environment is higher than ever. This highlights the need for efficient leak detection to prevent environmental catastrophes and operational disruption. Therefore, accurate techniques to detect and locate very small leaks that could develop into larger leaks are a valuable asset for the construction of key pipelines. External pipeline leak detection systems based on distributed fiber optic sensing emerge as the most appropriate solution for automatic detection and localization of very small leaks. In the case of the Kinosis pipeline system, two 11km Electrically Heat Traced Pipe-In-Pipe (EHTPIP) pipelines have been built between the Nexen Long lake upgrader and Nexen Kinosis SAGD facilities. The fiber optic sensing cable is directly in contact with the EHTPIP external surface. These pipelines carry Produced Emulsion and Boiler Feed Water at temperatures as high as 120°C and 150°C respectively. The fiber optic distributed sensing system provides temperature feedback information to the operator, not only in operation and in case of a leak but also when the Electrical Heat Trace system is turned on; in this case, the monitoring system can detect and locate overheating problems and/or signs of heating failures. In the case of a leak, the outer temperature of the pipeline will increase; this will automatically be detected and monitored by the DITEST temperature monitoring system and will trigger an alarm to the Nexen LONG LAKE upgrader SCADA system for that specific location. Furthermore, the combination of fiber optic distributed monitoring with the PIP technology enables to detect and locate a leak in the inner pipeline at a very early stage, therefore avoiding any environmental damage (the leak is still contained by the outer PIP tube) and giving time to the pipeline operator to plan a sectional replacement.
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