Preventive Maintenance Topic Models for LNG Containment Systems of LNG Marine Carriers Using Dock Specifications

Abstract

The high demand for liquefied natural gas (LNG) requires more LNG carriers (LNGCs) to be in operation. During transportation, there is a high risk due to the required extremely low temperatures and the explosive nature of LNG cargo. Moreover, when there is a lack of experience in operating old LNGCs, there is a serious concern regarding operational accidents. A systematic maintenance strategy, especially for LNG cargo containment systems, is crucial for maintaining safe LNG transportation at sea. The purpose of this study is to develop preventive LNG cargo containment system maintenance models by using LNGC dock specifications from LNGCs of various ages. The dock specifications from a conventional LNGC repairing dock were analyzed using natural language processing techniques in order to develop preventive maintenance models of the LNG cargo containment system. From these results, and by considering the ship’s age, it was found that for young LNGCs, the priority for repair should focus on checking routine consumable spare parts by tank inspections, whereas for older LNGCs, the focus should be on tank condition maintenance rather than on other facilities. These results are expected to be useful in the development of a maintenance strategy of preventive LNG cargo containment systems in maritime LNG transportation.

Environmental Vulnerability in Pre-Salt Oil and Gas Operations

“…In pre-salt fields, the amount of gas that is allowed to burn corresponds to a volume equal to or less than 3% of the monthly natural gas production associated with the field. The main substances emitted are greenhouse gases: CO 2 , CH 4 , N 2 O, and total hydrocarbons, as well as NO x , SO x , CO, and particulate matter [2,50,51].…”

“…In order to extract natural resources, it is necessary to know how the environment reacts to imposed anthropogenic pressures, as well as the degree of support for these pressures [60]. These resources, as discussed above, cause a wide variety of environmental impacts, which irreversibly compromise the ability of future generations to meet their own needs, endangering the environmental vulnerability of the Área Geográfica Bacia de Santos system [2,3,11]. Thus, with regard to the exploitation of natural resources, there are alternatives that can save the environmental factors studied above from these risks [2,3,10].…”

“…These resources, as discussed above, cause a wide variety of environmental impacts, which irreversibly compromise the ability of future generations to meet their own needs, endangering the environmental vulnerability of the Área Geográfica Bacia de Santos system [2,3,11]. Thus, with regard to the exploitation of natural resources, there are alternatives that can save the environmental factors studied above from these risks [2,3,10]. It is known that various reviews and studies are carried out around the world about environmental vulnerability (with varying degrees of analysis and accuracy, published or not), aiming at the diffuse goal of sustainable development and others such as the objectives of the millennium, as found in [13][14][15][16]25,26,28,61,62].…”

“…Fossil resources, such as oil and natural gas (NG), are non-renewable, as their formation is on a millennial scale. Hydrocarbons (HC) damage the planet from the moment of its invasive extraction (that has a risk of spillage) until its use (through the release of greenhouse gases (GHG), for example) [1][2][3][4].…”

“…The main presalt reserve is in the state of São Paulo (approximately 55 to 300 km from its coast). The Geographic Area of the Santos Basin (AGBS, Área Geográfica Bacia de Santos) has an area of 40,663 km 2 and is at a depth of 100 to 3000 m. In 2006, the Brazilian oil company, Petrobras, continued its exploration in order to discover new oil and gas fields, as it hoped to increase its national production: a goal that it successfully achieved. That same year, Petrobras estimated that it would drill 62 wells of the pre-salt reservoirs-25 exploratory and 27 development sites-from 2008 to 2010.…”