scholarly journals Decommissioning impacts on biotic assemblages associated with shell mounds beneath southern California offshore oil and gas platforms

2019 ◽  
Vol 95 (4) ◽  
pp. 683-702 ◽  
Author(s):  
Erin L Meyer-Gutbrod ◽  
Milton S Love ◽  
Jeremy T Claisse ◽  
Henry M Page ◽  
Donna M Schroeder ◽  
...  
Keyword(s):  
Species Composition ◽  
Southern California ◽  
Oil And Gas ◽  
Fish Assemblages ◽  
Ecological Value ◽  
Remotely Operated Vehicle ◽  
Wide Range ◽  
Shell Mounds ◽  
Offshore Oil And Gas ◽  
Offshore Oil

The decommissioning of southern California offshore oil and gas platforms will create major economic, engineering, and environmental challenges in the next decade. Platform jackets, conductors, and shell mounds often host a diverse and productive marine community, and among the myriad considerations associated with decommissioning planning, platform operators and federal and state regulatory agencies will consider the ecological value of existing underwater structures as artificial reefs. In the event of partial removal of platform structure, fish assemblages on decommissioned platforms may remain unchanged in areas where structure is left intact. However, on the seafloor beneath the platforms, a mound of debris often called the shell mound will likely change over time if the supply of falling mussels and other organisms from the productive surface part of the structure is removed. In this study, we review shell mound research relevant to decommissioning, including mound formation, contaminant loads, associated biological communities, and transitions following the removal of platform structures at four sites. To address the gap in knowledge of shell mound fish community structure, we used manned submersible and remotely operated vehicle surveys from 1997 to 2013 to estimate the biomass, density, species composition and similarity between shell mounds at 22 southern California platforms. We found a wide range of variability in fish density and shell mound areal extent. Species composition also varied among sites, with three significant community clusters primarily distinguished by species depth preferences. These results will help inform a comprehensive net environmental benefit analysis of southern California offshore platform decommissioning alternatives.

scholarly journals An analysis of the fish assemblages around 23 oil and gas platforms off California with comparisons with natural habitats

2019 ◽  
Vol 95 (4) ◽  
pp. 477-514 ◽  
Author(s):  
Milton S Love ◽  
Jeremy T Claisse ◽  
Alexa Roeper
Keyword(s):  
Oil And Gas ◽  
Fish Assemblages ◽  
Habitat Type ◽  
Geographic Location ◽  
Natural Habitats ◽  
Central California ◽  
Shell Mounds ◽  
Young Of The Year ◽  
Offshore Oil And Gas ◽  
Offshore Oil

Between 1995 and 2013, we surveyed fishes living around 23 California offshore oil and gas platforms (midwaters, bases, and shell mounds) and 70 natural habitats. These platforms were distributed between about Point Arguello, central California, and Huntington Beach, southern California, had seafloor depths between 49 and 363 m, and were surveyed between one and 16 times. A total of 1,526,437 fishes were observed. Fish densities were highest around platform bases, followed by platform midwaters, shell mounds, and natural habitats. Of all fishes observed, 90.4% were in the genus Sebastes. Water depth was the strongest driver of the fish species assemblages, although habitat type and geographic location were also important. Most of the fishes living around platforms and natural habitats were relatively small, primarily ≤20 cm in length. Many of these individuals were the juveniles of larger taxa or the juveniles and adults of dwarf species. Larger fishes were less common and these were most often found around platform bases and on natural habitats. Most young-of-the-year (YOY) fishes occurred at water depths of ≤150 m at all four habitats. At platforms, YOY densities were highest in platform midwaters and bases. On average, densities of these young fishes were somewhat higher compared to natural habitats and it is likely that many, although not all, California platforms play a significant role as nursery grounds for a variety of fishes, particularly for a number of Sebastes species.

scholarly journals Effect of Gain in Soil Friction on the Walking Rate of Subsea Pipelines

2019 ◽  
Vol 7 (11) ◽  
pp. 401 ◽  
Author(s):  
Zhaohui Hong ◽  
Dengfeng Fu ◽  
Wenbin Liu ◽  
Zefeng Zhou ◽  
Yue Yan ◽  
...  
Keyword(s):  
Oil And Gas ◽  
Oil And Gas Industry ◽  
Pipeline System ◽  
Gas Industry ◽  
Steel Catenary Riser ◽  
Wide Range ◽  
Offshore Oil And Gas ◽  
Subsea Pipelines ◽  
Offshore Oil ◽  
Pipeline Design

Subsea pipelines are commonly employed in the offshore oil and gas industry to transport high-pressure and high-temperature (HPHT) hydrocarbons. The phenomenon of pipeline walking is a topic that has drawn a great deal of attention, and is related to the on-bottom stability of the pipeline, such as directional accumulation with respect to axial movement, which can threaten the security of the entire pipeline system. An accurate assessment of pipeline walking is therefore necessary for offshore pipeline design. This paper reports a comprehensive suite of numerical analyses investigating the performance of pipeline walking, with a focus on the effect of increasing axial soil resistance on walking rates. Three walking-driven modes (steel catenary riser (SCR) tension, downslope, and thermal transient) are considered, covering a wide range of influential parameters. The variation in walking rate with respect to the effect of increased soil friction is well reflected in the development of the effective axial force (EAF) profile. A method based on the previous analytical solution is proposed for predicting the accumulated walking rates throughout the entire service life, where the concept of equivalent soil friction is adopted.

scholarly journals Contesting Political Decisions Involving Environmental Issues: A Case Study in Portugal Based on the Press About Offshore Oil and Gas Drilling

2021 ◽  
Vol 8 ◽  
Author(s):  
Bruno Pinto ◽  
Paula Castro
Keyword(s):  
Oil And Gas ◽  
Oil Companies ◽  
Gas Drilling ◽  
Wide Range ◽  
The Press ◽  
The Government ◽  
Offshore Oil And Gas ◽  
Offshore Oil ◽  
Political Decisions

This paper presents a case study about the drilling of offshore oil and gas in mainland Portugal, a process that ended with the cancelation of all contracts. It aimed to better understand the argumentative and value dynamics involved in how municipalities, populations, civic organizations, and others successfully contested the central government decision of prospection. Since the press was one of the main stages for this conflict, it was important to analyze how it presented the respective arguments to society. Articles on this topic were collected from the two widely read national newspapers “Correio da Manhã” and “Público” in the culmination period of this confrontation, which occurred between June 2016 and December 2018. In total, 155 articles were found, 61.3% (n = 95) from “Público” and 38.7% (n = 60) from “Correio da Manhã.” The quantitative analysis focused on the number of news per month and the frequency of themes, as well as the frequency of actors and arguments used against and in favor of exploitation on the news. Thematic analysis was used to qualitatively assess the articulation of arguments in the two opposing views. Results show that, in both newspapers, the majority of articles focused on the positions and actions of those opposing prospection, as the Government and other actors in favor of drilling were much less active in presenting its arguments. Overall, the analysis suggests two different strategies: (a) a strong argumentative synergy between a wide range of actors against offshore prospection. Their concerted arguments defended multiple values, including public participation in political decisions, protecting local communities and places from environmental risks, countering climate change, and protecting local economic activities. (b) The Government was usually isolated in its arguments with the occasional exception of oil companies or representatives of the national industry. The scarce arguments used by these actors evoked mostly national economic values, with little engagement with other societal goals. This study suggests that the large mobilization of different sectors of society, their use of a convergent and wide range of arguments, and the lack of engagement of the Government in a dialogical argumentation were crucial to delegitimize the latter’s political decision.

scholarly journals Fishes and invertebrates of oil and gas platforms off California: an introduction and summary

2019 ◽  
Vol 95 (4) ◽  
pp. 463-476 ◽  
Author(s):  
Milton S Love
Keyword(s):  
Southern California ◽  
Oil And Gas ◽  
Current Operator ◽  
Outer Continental Shelf ◽  
The Pacific ◽  
Introductory Paper ◽  
Removal Weight ◽  
Offshore Oil And Gas ◽  
Bottom Depth ◽  
Offshore Oil

This paper serves as an introduction to a symposium on the role that California oil and gas platforms serve as habitats for fishes and invertebrates. As of 2019, there are 27 platforms in state and federal waters off California, and the decommissioning of some of these platforms is imminent. Thus, consideration of whether to completely remove a platform or cut it off at some depth below the sea surface and retain the submerged portion as a reef is a decision that will occur in the near future. The objectives of the 10 papers in this dedicated issue of the Bulletin of Marine Science are to: (1) increase scientific understanding of the inter- and intrarelationships of fish and invertebrate populations at offshore oil and gas platforms and natural reefs within the Southern California Bight; (2) determine the extent of influence of platform assemblages on southern California and the Pacific coast populations of fishes and invertebrates; and (3) synthesize relevant reports, existing peer-reviewed literature, and new data analyses into a single peer-reviewed reference. This introductory paper contains a synopsis of all extant California platforms including information on: (1) the original operator, (2) the current operator of records, (3) the date the platform was installed, (4) the first production date, (5) the platform's distance from shore [including whether it is state or outer continental shelf (OCS) waters], (6) the bottom depth of the platform, (7) the number of well slots, (8) the number of conductors, (9) what the platform produces (oil and/or gas), (10) the platform jacket dimensions [generally at the seafloor (bottom)], (11) the platform's footprint, (12) the midwater surface area, (13) the total removal weight, (14) the platform location, (15) the shell mound size, (16) the shell mound volume, (17) the shell mound height, (18) the center of the shell mound location, and (19) the bottom slope. In addition, we present an overview of all previous research on the biology and ecology of California platform organisms.

Underwater robots: a review of technologies and applications

2015 ◽  
Vol 42 (3) ◽  
pp. 186-191 ◽  
Author(s):  
Robert Bogue
Keyword(s):  
Deep Sea ◽  
Oil And Gas ◽  
Autonomous Underwater Vehicle ◽  
Underwater Robot ◽  
Remotely Operated Vehicle ◽  
Underwater Robots ◽  
Content Type ◽  
Offshore Oil And Gas ◽  
Offshore Oil ◽  
Oil And Gas Sector

Purpose This paper aims to provide details of underwater robot technology and its applications. Design/methodology/approach Following an introduction, this article first discusses remotely operated vehicle (ROV) technology and applications and then considers their use in the emerging field of deep-sea mining. It then discusses autonomous underwater vehicle (AUV) technology and its applications, including sub-sea gliders. Finally, brief concluding comments are drawn. Findings ROVs were first developed in the 1950s for military applications. They are now widely used by the offshore oil and gas sector and other industries and are being developed for deep-sea mining. AUV technology has progressed rapidly in recent years and AUVs, including sub-sea gliders, are now emerging from their original role in oceanographic research and finding growing uses in the defence and offshore energy sectors. Originality/value This provides a detailed insight into underwater robot technologies, products and applications.

Designing, Making, and Testing Syntactic Foam of Precisely Controlled Hydrostatic Strength

2003 ◽  
Author(s):  
Wen-Tsuen Wang ◽  
Lou Watkins
Keyword(s):  
Oil And Gas ◽  
Syntactic Foam ◽  
Confined Space ◽  
Foam Material ◽  
Gas Wells ◽  
Wide Range ◽  
Oil And Gas Wells ◽  
Temperature And Pressure ◽  
Offshore Oil And Gas ◽  
Offshore Oil

This paper describes a recently developed syntactic foam material designed to collapse under precisely defined conditions of temperature and pressure to protect ultra-deep high pressure offshore oil and gas wells. Each grade of syntactic foam is engineered to have a specific set of characteristics, tailored for the region of the well it occupies. In the startup phase, the materials remain intact, with no significant volume change. As pressure and temperature in the well rise during operations, the materials begin to compress and relieve pressure in the narrow, confined space of the annulus. Finally, when conditions reach preset limits, the syntactic foam undergoes a sudden and dramatic collapse, preventing excessive overpressure, and protecting the steel casing. An important advantage of this material is that it is passive, requiring no controls or active intervention. It responds automatically to protect the well casing from overpressures and temperature spikes. The properties of the material can be adjusted to suit a wide range of conditions inside a given well, or from one well to another.

The Application of ROV for the Subsea Christmas Tree Installation in the LiWan3-1 Deepwater Oilfield

2013 ◽  
Vol 331 ◽  
pp. 39-42
Author(s):  
Jin Gan Zhang ◽  
Hui Zheng ◽  
Jian Gen Bu ◽  
Cheng Gang Li
Keyword(s):  
Deep Water ◽  
Oil And Gas ◽  
Production Systems ◽  
Christmas Tree ◽  
Oil Well ◽  
Remotely Operated Vehicle ◽  
Well Production ◽  
Indispensable Tool ◽  
Offshore Oil And Gas ◽  
Offshore Oil

Chinas offshore oil and gas has been developed from shallow water to deep water. Subsea production facilities play more and more role in deepwater oil and gas fields, in which Christmas tree is the key equipment to control and regulate the oil well production of deepwater production systems, but it has great installation costs and risk. For complex underwater environment, it is necessary to find a best way to install the Christmas tree securely and rapidly. ROV (Remotely Operated Vehicle) is wildly used in the field of offshore oil, especially in deep water for its large working depth, safe, efficient and other characteristics, and it has become an indispensable tool for development of deep-sea oil and gas. In one Christmas tree installation at Liwan3-1 deepwater oilfield, the ROV succeeded in assisting the installation of Christmas tree. The solutions for winding and wrong operation risk in installation process are given in the end.

scholarly journals Fish Assemblages Associated With Oil and Gas Platforms in the Gulf of Thailand

2021 ◽  
Vol 8 ◽  
Author(s):  
Euan S. Harvey ◽  
Stephanie L. Watts ◽  
Benjamin J. Saunders ◽  
Damon Driessen ◽  
Laura A. F. Fullwood ◽  
...  
Keyword(s):  
Coral Reef ◽  
Oil And Gas ◽  
Fish Assemblages ◽  
Economic Value ◽  
Offshore Structures ◽  
Economic Benefits ◽  
Gulf Of Thailand ◽  
Reference Sites ◽  
Remotely Operated Vehicle ◽  
Offshore Oil And Gas

Decommissioning of offshore oil and gas structures is either occurring, or imminent in most regions of the world. Most jurisdictions require that offshore structures be removed for onshore disposal. However, there is growing interest in understanding the ecological and socio-economic benefits of leaving structures in the water. Descriptions of how fish utilize the vertical structure created by wellhead platform jackets (platforms) will provide insights into possible outcomes of decommissioning alternatives, such as full removal, leave in situ, or translocation to a designated reefing site. We surveyed fish assemblages associated with seven platforms and five reference sites located ∼150 km offshore in the central Gulf of Thailand. The platforms spanned the entire water column (∼75 m) and were a mix of three and four legged structures. We used a Remotely Operated Vehicle (ROV) fitted with an underwater stereo video system to quantify the abundance, size, biomass, and economic value of fish associated with the platforms. We recorded 43 species of fish on the platforms and five reference sites with most fishes on platforms categorized as coral-reef or coral-reef-associated species. We observed a strong vertical zonation in the fish assemblage on the platforms. The Regal demoiselle (Neopomacentrus cyanomos) was numerically dominant (75% of all fish observed). We measured 3,933 kg of fish on the platforms with Caranx sexfasciatus accounting for 76.12% of that. We conservatively estimate each platform had a scaled mean biomass of ∼2,927 kg and the fished species had scaled mean economic value of 175,500 Thai Baht per platform. We estimated that the biomass of fish associated with the seven platforms was at least four times higher per unit area than some of the world’s most productive coral reefs.

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