Disposable Fibre Optic Intervention System: Case Study of Successful Leak Detection Offshore North Sea

2021 ◽  
Author(s):  
Craig Feherty ◽  
Andrew Garioch ◽  
Annabel Green

Abstract Maintaining well integrity is critical to sustaining production from mature and aging fields. Disposable fibre optic technology has been deployed in wells in the North Sea to locate known tubing leaks in the completion. The disposable fibre optic intervention system releases a probe into the well to enable the deployment of bare fibre optic line. The fibres are released from the probe as it descends into the well. In the presented case study, the probe contained both single-mode and multi-mode fibre optic lines to enable simultaneous Distributed Temperature Sensing (DTS) and Distributed Acoustic Sensing (DAS) surveys to be performed. Once deployed in the well, pressure manipulation programs were performed to activate any tubing or casing leaks while acquiring DTS and DAS data. As a result of the exceptional sensitivity of the bare fibres and the effective coupling of the fibre with the tubing wall the technology is shown to be highly effective in detecting leaks and confirming barrier integrity. In the presented example a leak was located along with the direction and rate of the fluid movement in the ‘B’ annulus. The simplicity of the system and highly efficient operations greatly reduced survey times in comparison to conventional intervention techniques thereby greatly reducing the cost of intervention. It can be demonstrated that the disposable fibre optic deployment system provides a game changing and cost-effective solution for both leak detection and determining liquid levels in the wells. The disposable fibre solution is a unique deployment method which provides an alternative to conventional well surveys, reducing the complexity, time and cost to acquire valuable distributed well data. This is the first case history published for this technology in leak detection application.

Author(s):  
Kathryn M. de Luna

This chapter uses two case studies to explore how historians study language movement and change through comparative historical linguistics. The first case study stands as a short chapter in the larger history of the expansion of Bantu languages across eastern, central, and southern Africa. It focuses on the expansion of proto-Kafue, ca. 950–1250, from a linguistic homeland in the middle Kafue River region to lands beyond the Lukanga swamps to the north and the Zambezi River to the south. This expansion was made possible by a dramatic reconfiguration of ties of kinship. The second case study explores linguistic evidence for ridicule along the Lozi-Botatwe frontier in the mid- to late 19th century. Significantly, the units and scales of language movement and change in precolonial periods rendered visible through comparative historical linguistics bring to our attention alternative approaches to language change and movement in contemporary Africa.


2019 ◽  
Vol 58 (2) ◽  
pp. 315-337 ◽  
Author(s):  
Thomas Cogswell

AbstractHistorians have not paid close attention to the activities of freebooters operating out of Dunkirk in the late 1620s. This essay corrects that omission by first studying the threat from Dunkirk to England's east coast and then addressing how the central government, counties, and coastal towns responded. A surprisingly rich vein of manuscript material from Great Yarmouth and particularly from the Suffolk fishing community of Aldeburgh informs this case study of the impact of this conflict around the North Sea.


2021 ◽  
Author(s):  
Matthew Kelsey ◽  
Magnus Raaholt ◽  
Olav Einervoll ◽  
Rustem Nafikov ◽  
Stian Amble

Abstract Multilateral technology has for nearly three decades extended the production life of fields in the North Sea by delivering a higher recovery factor supported by the cumulative production of the multiple laterals. Additionally, operators continue to look at methods to reduce the environmental impact of drilling and intervention. Taking advantage of the latest multilateral technology can turn otherwise unviable reservoirs into economically sound targets by achieving a longer field life while minimizing construction costs, risk, and environmental impact. This paper will focus on mature fields in the region that have used multilateral applications for wells that were reaching the end of their life and have been extended to further economic production. This paper discusses challenges faced to provide a multilateral solution for drilling new lateral legs in existing wells where there is a lack of available slots to drill new wells. Additionally, discussion will cover completion designs that tie new laterals into existing production casing. The case study will include discussion of workover operations, isolation methods, and lateral creation systems. The paper focuses on the challenges, solutions, and successful case study of a retrofit multilateral well constructed in the North Sea which extended production life in a mature field by using innovative multilateral re-entry methods. The paper also provides insight as to methodology for continually improving reliability of multilateral installations to maximize efficiencies.


2015 ◽  
Vol 19 (6) ◽  
pp. 2663-2672 ◽  
Author(s):  
A.-M. Kurth ◽  
C. Weber ◽  
M. Schirmer

Abstract. In this study, we investigated whether river restoration was successful in re-establishing groundwater–surface water interactions in a degraded urban stream. Restoration measures included morphological changes to the river bed, such as the installation of gravel islands and spur dykes, as well as the planting of site-specific riparian vegetation. Standard distributed temperature sensing (DTS) and novel active and passive DTS approaches were employed to study groundwater–surface water interactions in two reference streams and an experimental reach of an urban stream before and after its restoration. Radon-222 analyses were utilized to validate the losing stream conditions of the urban stream in the experimental reach. Our results indicated that river restoration at the study site was indeed successful in increasing groundwater–surface water interactions. Increased surface water downwelling occurred locally at the tip of a gravel island created during river restoration. Hence, the installation of in-stream structures increased the vertical connectivity and thus groundwater–surface water interactions. With the methods presented in this publication, it would be possible to routinely investigate the success of river restorations in re-establishing vertical connectivity, thereby gaining insight into the effectiveness of specific restoration measures. This, in turn, would enable the optimization of future river restoration projects, rendering them more cost-effective and successful.


2018 ◽  
Vol 156 (07) ◽  
pp. 1265-1284
Author(s):  
EVA VAN DER VOET ◽  
LEONORA HEIJNEN ◽  
JOHN J. G. REIJMER

AbstractIn contrast to the Norwegian and Danish sectors, where significant hydrocarbon reserves were found in chalk reservoirs, limited studies exist analysing the chalk evolution in the Dutch part of the North Sea. To provide a better understanding of this evolution, a tectono-sedimentary study of the Late Cretaceous to Early Palaeogene Chalk Group in the northern Dutch North Sea was performed, facilitated by a relatively new 3D seismic survey. Integrating seismic and biostratigraphic well data, seven chronostratigraphic units were mapped, allowing a reconstruction of intra-chalk geological events.The southwestward thickening of the Turonian sequence is interpreted to result from tilting, and the absence of Coniacian and Santonian sediments in the western part of the study area is probably the result of non-deposition. Seismic truncations show evidence of a widespread inversion phase, the timing of which differs between the structural elements. It started at the end of the Campanian followed by a second pulse during the Maastrichtian, a new finding not reported before. After subsidence during the Maastrichtian and Danian, renewed inversion and erosion occurred at the end of the Danian. Halokinesis processes resulted in thickness variations of chalk units of different ages.In summary, variations in sedimentation patterns in the northern Dutch North Sea relate to the Sub-Hercynian inversion phase during the Campanian and Maastrichtian, the Laramide inversion phase at the end of the Danian, and halokinesis processes. Additionally, the Late Cretaceous sea floor was characterized by erosion through contour bottom currents at different scales and resedimentation by slope failures.


2018 ◽  
Vol 45 ◽  
pp. 01001
Author(s):  
Yasser Arab ◽  
Ahmad Sanusi Hassan ◽  
Bushra Qanaa

The study investigates apartment’s façade thermal performance with neo-minimalist architectural style in Penang, Malaysia. Neo-minimalist style is considered as the most popular style in Malaysia in 2010s. The style is rediscovering from early modern minimalist movement with a design concept “less is more”. It applies minimal and efficient design of architectural character in defining form and space. Penang Island the second most important city in Malaysia after Kuala Lumpur. It is located at the north-western part of the country. The first case studies is the Light Linear apartment which has sixteen stories located on the east cost of Penang Island at Pantai Street, Penang. The second case study is BayStar apartment building, the eleven stories building tis located in Bayan Lepas at the seaside facing Jerejak Island. In order to conduct this study Fluke Ti20 thermal imager was used to capture thermal images for the west facades of the selected case study hourly from 12:00 to 6:00 pm on 15th March 2017. The study finds that the recessed wall, balconies and the shading devices were the important elements to provide shades on the façades for good thermal performance.


2020 ◽  
Author(s):  
Alec P. Christie

AbstractSeabird movements and diet during the non-breeding season are poorly studied, yet understanding these aspects of seabird ecology is extremely important to effectively conserve these protected species. Stable isotope analyses (SIA) provide a cost-effective solution to filling these knowledge gaps, yielding information on diet and foraging locations of animals. This study aimed to use SIA to investigate whether Common Guillemots (Uria aalge) from different age classes and locations in the UK had contrasting diets and foraging areas during the post-breeding moult (July-September). SIA of secondary feathers and a newly-developed North Sea isoscape were used to identify the likeliest foraging areas and diets of deceased guillemots recovered from beaches in eastern Scotland and mixed fisheries in Cornwall and the Celtic Sea. Overall, guillemots foraged widely in the western, eastern and southern North Sea, consuming a variety of clupeid, gadoid and invertebrate prey. There were negligible dietary differences between age classes and birds from different recovery locations. Juveniles showed a wider range in foraging areas, but both age classes foraged in similar parts of the North Sea. Guillemots recovered from Scotland may have foraged further north, only overlapping with guillemots recovered from the southwestern UK in the southern and eastern North Sea. Their winter recovery locations also implied that they exhibited different movement strategies during the non-breeding season, meriting further investigation. Conservation efforts should target foraging areas in the southern and eastern North Sea which are highly threatened by gillnet fishing, shipping traffic and oil infrastructure.


Author(s):  
R. Veenhof ◽  
T.J. Moser ◽  
I. Sturzu ◽  
D. Dowell ◽  
A.M. Popovici ◽  
...  

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