7 results on '"Mohd Hairil Mohd"'
Search Results
2. Improving Biological Reefing Viability Index as a Predictive Tool for Assessment of Potential Reefing Site in the Tropical Shallow Offshore Environment
- Author
-
Mohd Asamudin A. Rahman, Mohd Izzat Mohd Thiyahuddin, Chun Hong Tan, Yii Siang Hii, and Mohd Hairil Mohd
- Subjects
Hydrology ,Index (economics) ,Environmental science ,Submarine pipeline - Abstract
The current study improved the predictive capability of the biological reefing viability index (BRVI) calibrated using local data. The prediction capability of the BRVI improved from 61% to 76% accuracy out of the 181 locations where the underwater videos available for verification. The BRVI includes corals larvae density, age of larvae at site, sea current, sea temperature, chlorophyll-a, water depth and sediment type to predict biological productivity of an area. Among the parameters, corals larvae density and age of the larvae are the most critical parameters that influent establishment of new biological ecosystem. The BRVI uses settlement of corals larvae as the precursors for the establishment of new habitats in the offshore environment because scleractinian corals is known to be able to form backbone of a new habitat in the environment. In this approach, the BRVI focuses on habitat creation instead of just being a fish aggregating device (FAD) when an artificial reef is deployed in an area. The BRVI can be used as a rapid screening tool to identified potential area for deployment of artificial reefs. The BRVI could reduce the chances of artificial reefs deployment that failed to address its objectives and intended outcomes.
- Published
- 2021
3. Marine Life Assemblage Assessment at Oil & Gas Platform in the South China Sea Offshore Malaysia
- Author
-
Emily Hazelwood, Mohd Izzat Mohd Thiyahuddin, Azam Abdul Rahman, Amberlea Sparks, Mohd Hairil Mohd, Mark Benfield, Mohd Asamudin A. Rahman, Y. Yusuf, and Chun Hong Tan
- Subjects
Oceanography ,South china ,Assemblage (archaeology) ,Environmental science ,Marine life ,Submarine pipeline - Abstract
In Malaysia, numerous offshore oil and gas platforms are approaching the end of their operational lifespans and will soon be scheduled for decommissioning. Traditional decommissioning typically involves the complete removal of the platform from the seabed, consequently resulting in the destruction of the established marine life communities present on the structure. A Rigs-to-Reefs strategy provides an alternative to the complete removal of obsolete, non-productive offshore oil and gas platforms, by converting the platform into a permanent artificial reef by utilizing one of the following three methods: partial removal or topple-in-place (in-situ), or tow and place (ex-situ). In-situ reefing provides a means of conserving the marine communities found on the platform by decommissioning the platform jacket in place as an artificial reef. However, not all platforms are good candidates for a Rigs-to-Reef conversion. Thus, pre-decommissioning biological assessments should be undertaken to determine the most appropriate decommissioning strategy on a case-by-case basis. In this study, a biological assessment was developed to catalog the marine life assemblages present on two offshore oil and gas platforms in Malaysia using remotely operated vehicles. Given the limited amount of biological data available on the marine ecosystems found on Malaysia’s platforms, this data may be useful for minimizing adverse impacts of platform removal, while enhancing benefits to the marine environment.
- Published
- 2021
4. Reefing Viability Index for Rigs-to-Reefs (R2R) in Malaysia
- Author
-
Baharim Mustapa, Chuin Siew Lim, Mohd Hairil Mohd, Yuzwan Mohamad, Chun Hong Tan, Hasrizal Shaari, Do Kyun Kim, Yii Siang Hii, Mohd Asamudin A. Rahman, and Muhammad Nadzrin Nazri
- Subjects
0106 biological sciences ,Technology ,Article Subject ,Coral ,Oceans and Seas ,Science ,Oil and Gas Industry ,Marine Biology ,Remotely operated vehicle ,010603 evolutionary biology ,01 natural sciences ,General Biochemistry, Genetics and Molecular Biology ,Humans ,Marine ecosystem ,Oil and Gas Fields ,Petroleum Pollution ,Reef ,Ecosystem ,General Environmental Science ,geography ,geography.geographical_feature_category ,Coral Reefs ,010604 marine biology & hydrobiology ,Malaysia ,Pelagic zone ,General Medicine ,Coral reef ,Fishery ,Environmental science ,Medicine ,Submarine pipeline ,Artificial reef ,Research Article - Abstract
Decommissioning of the offshore platform as an artificial reef, known as Rigs-to-Reefs (R2R), has become a sustainable approach for oil companies. The platform was reused to serve the underwater ecosystem as an artificial reef for a new marine ecosystem which helps to tackle food security issue. This paper presents the findings of the formulation of the reefing viability index to recognize an offshore region that can be used for R2R projects within the South China Sea. The combined effects of spatial data, numerical modelling, and geographic system (GIS) are proposed to study the relationship of spawning ground coral reefs, diversity, and planula larvae in the process of colonization to establish a map of the reef potential environment. Coral connectivity and spawning behaviour were studied to determine the possible source of coral seedling released during the spawning season, twice a year. A geographic reef viability index was established consisting of seven parameters which are coral larval density, pelagic larval length, sea currents, temperature, chlorophyll-a, depth, and substrate availability. The ocean hydrodynamic model was designed to resemble the pattern of larval scattering. By using the simulations and rankings, there were 95 (21%) sites which could probably be used for in situ reefing, whereas 358 (79%) sites were likely ideal for ex situ reefing. Validation of the viability index was carried out using media footage assessment of remotely operated vehicle (ROV).
- Published
- 2020
- Full Text
- View/download PDF
5. Risk Assessment of Fishing Trawl Activities to Subsea Pipelines of Sabah and Labuan Waters
- Author
-
Ahmad Faizal Ahmad Fuad, Mohd Asamudin A. Rahman, Mohd Hairil Mohd, Ismail Zainol, Khalid Samo, and Mohd Hafizi Said
- Subjects
0106 biological sciences ,Technology ,Article Subject ,Oceans and Seas ,Science ,Fishing ,Fisheries ,020101 civil engineering ,02 engineering and technology ,Risk Assessment ,01 natural sciences ,General Biochemistry, Genetics and Molecular Biology ,0201 civil engineering ,Seabed ,General Environmental Science ,Shore ,geography ,geography.geographical_feature_category ,Trawling ,010604 marine biology & hydrobiology ,Malaysia ,General Medicine ,Models, Theoretical ,Bottom trawling ,Pipeline transport ,Fishery ,Environmental science ,Medicine ,Submarine pipeline ,Algorithms ,Research Article ,Subsea - Abstract
Introduction. Trawling is a method of catching fish in a large volume where fish nets are pulled through water using one or two boats. Bottom trawling is where the nets are pulled over on the seabed. The gear of the bottom trawling would impact the exposed subsea pipeline, on the seabed. Subsea pipelines transport crude oil and gas from the offshore platform to shore facility. This study assesses the risk of fish trawling activities to the subsea pipelines at Sabah and Labuan offshore. The specification of trawl equipment used by local trawlers in Sabah was determined by the on-site survey. The frequency of a fish trawler crossing over the pipelines was calculated based interview on operation and site survey. The calculation of the pull-over load of the otter board was calculated using the DNVGL algorithm. The severity and frequency index of the risk matrix was developed based on literature review. Results showed that the pull-over load of the otter board would not damage the pipelines. The risk posed by the fish trawler activity to the pipelines is low and moderate.
- Published
- 2020
6. Potential of Offshore Structure as Artificial Reefs in Shallow Tropical Water
- Author
-
Chun Hong Tan, Mohd Shahir Liew, Wesam Salah Alaloul, Lim Eu Shawn, Iraj Toloue, Hasrizal Shaari, Noor Amila Wan Abdullah Zawawi, Baharim Mustapa, Yii Siang Hii, Muhammad Nadzrin Nazri, Mohd Hairil Mohd, Mohd Asamudin A. Rahman, M Nasahie Akbar Ali, M Izzat Thiyauddin, Marcella Abdul Karim, Yuzwan Mohamad, and Chuin-Siew Lim
- Subjects
021103 operations research ,Oceanography ,020209 energy ,0211 other engineering and technologies ,0202 electrical engineering, electronic engineering, information engineering ,Submarine pipeline ,02 engineering and technology ,Tropical waters ,Geology ,Artificial reefs - Abstract
Reefing of Oil and Gas structure has become as one of the emerging options for decommissioning of an O&G Structure offshore and requires expert input beyond engineering such as biomarine and environmental sciences. This paper will present the interdisciplinary collaborative effort by industries with academia in Malaysia in developing a reef viability index as the first high level screening to assess the suitability of decommissioning using the reefing option in the region. The results of the reef viability index formulation to identify an offshore area that potential to be used for Rigs-to-Reefs (RTR) program in the South China Sea. The integration of data collection, numerical modelling and Geographic Information System (GIS) aims to review the relationship of coral reefs spawning ground, diversity and planula larvae in the colonization process which to produce a reefing area map. Coral connectivity and spawning behaviour were investigated to reveal the potential source of coral seedling as well as the number of coral larvae based on different taxa released during the spawning seasons. A spatial reef viability index was developed based on seven parameters, i.e. coral larval density, pelagic larval duration, sea currents, temperature, chlorophyll-a, depth, and substrate availability. Hydrodynamic model was developed to emulate the pattern of larval scattering. Based on the simulation and rankings, there were 95 (21%) sites that are most likely for in-situ reefing while the remaining 358 (79%) sites were probably suitable for ex-situ reefing or decommissioning. Validation of the viability index was done using Remotely Operated Vehicle (ROV) media footage assessment.
- Published
- 2019
7. Ultimate bending capacity of aged fixed platform by considering the effect of marine fouling
- Author
-
M. A. Zalaya, Mohd Hairil Mohd, Mohamed Latheef, Do Kyun Kim, H.S. Choi, and Mohd Asamudin A. Rahman
- Subjects
Fouling ,Mechanical Engineering ,Aerospace Engineering ,Ocean Engineering ,Turbine ,Corrosion ,Offshore wind power ,Mechanics of Materials ,Automotive Engineering ,Service life ,Environmental science ,General Materials Science ,Submarine pipeline ,Structural health monitoring ,Size effect on structural strength ,Civil and Structural Engineering ,Marine engineering - Abstract
For offshore structures, especially jacket supported structure such as fixed platform and offshore wind turbine, the underwater area provides an ideal site for corrosion formation and marine fouling. In this marine environment, the structures are exposed to particularly aggressive corrosion and colonized by marine organisms involving a diversity of species. In this paper, a number of cases are conducted where an existing fixed platform is subjected to uniform corrosion. Furthermore, the platform is also subjected to marine fouling. The platform is assessed to investigate the effects of corrosion and marine fouling on its structural strength by determining the Reserve Strength Ratio (RSR) value. It is found the platform is limited to at least 50 years of service life when subjected to average corrosion. However, the platform is no longer considered as safe after 37 years when subjected to severe corrosion. Moreover, there is an RSR loss of 38% when marine fouling is introduced at the first 5 years which is detrimental to the overall safety of the platform. On the other hand, there is minimum RSR loss of only 5% for most cases when marine fouling is introduced but still detrimental to the overall safety of the platform. The obtained outcomes were documented and will be useful information to conduct condition assessment (or structural health monitoring) of aged fixed jacket structures.
- Published
- 2019
Catalog
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.