The Experts below are selected from a list of 1533 Experts worldwide ranked by ideXlab platform
Samuel J Arey - One of the best experts on this subject based on the ideXlab platform.
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petroleum dynamics in the sea and influence of subsea dispersant injection during deepwater horizon
Proceedings of the National Academy of Sciences of the United States of America, 2017Co-Authors: Christopher M. Reddy, Jonas Gros, Scott A Socolofsky, Anusha L Dissanayake, Inok Jun, Lin Zhao, Michel C Boufadel, Samuel J AreyAbstract:Abstract During the Deepwater Horizon disaster, a substantial fraction of the 600,000–900,000 tons of released petroleum liquid and natural gas became entrapped below the sea surface, but the quantity entrapped and the sequestration mechanisms have remained unclear. We modeled the buoyant jet of petroleum liquid droplets, gas bubbles, and entrained seawater, using 279 simulated chemical components, for a representative day (June 8, 2010) of the period after the sunken platform’s Riser Pipe was pared at the wellhead (June 4–July 15). The model predicts that 27% of the released mass of petroleum fluids dissolved into the sea during ascent from the pared wellhead (1,505 m depth) to the sea surface, thereby matching observed volatile organic compound (VOC) emissions to the atmosphere. Based on combined results from model simulation and water column measurements, 24% of released petroleum fluid mass became channeled into a stable deep-water intrusion at 900- to 1,300-m depth, as aqueously dissolved compounds (∼23%) and suspended petroleum liquid microdroplets (∼0.8%). Dispersant injection at the wellhead decreased the median initial diameters of simulated petroleum liquid droplets and gas bubbles by 3.2-fold and 3.4-fold, respectively, which increased dissolution of ascending petroleum fluids by 25%. Faster dissolution increased the simulated flows of water-soluble compounds into biologically sparse deep water by 55%, while decreasing the flows of several harmful compounds into biologically rich surface water. Dispersant injection also decreased the simulated emissions of VOCs to the atmosphere by 28%, including a 2,000-fold decrease in emissions of benzene, which lowered health risks for response workers.
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floating oil covered debris from deepwater horizon identification and application
Environmental Research Letters, 2012Co-Authors: Catherine A Carmichael, Laura J. Linn, William M Graham, Samuel J Arey, Karin L Lemkau, Robert K Nelson, Christopher M. ReddyAbstract:The discovery of oiled and non-oiled honeycomb material in the Gulf of Mexico surface waters and along coastal beaches shortly after the explosion of Deepwater Horizon sparked debate about its origin and the oil covering it. We show that the unknown pieces of oiled and non-oiled honeycomb material collected in the Gulf of Mexico were pieces of the Riser Pipe buoyancy module of Deepwater Horizon. Biomarker ratios confirmed that the oil had originated from the Macondo oil well and had undergone significant weathering. Using the National Oceanic and Atmospheric Administration's records of the oil spill trajectory at the sea surface, we show that the honeycomb material preceded the front edge of the uncertainty of the oil slick trajectory by several kilometers. We conclude that the observation of debris fields deriving from damaged marine materials may be incorporated into emergency response efforts and forecasting of coastal impacts during future offshore oil spills, and ground truthing predicative models.
Masahiko Ozaki - One of the best experts on this subject based on the ideXlab platform.
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development of new device for reduction of fluctuating lift on Riser Pipe
The Twenty-fifth International Ocean and Polar Engineering Conference, 2015Co-Authors: Sadato Sugiyama, Masahiko Ozaki, Hideyuki Suzuki, Hiroyuki Yamamoto, Akio Usami, Koki Hirano, Masanori Kyo, Eigo MiyazakiAbstract:This paper describes a new technology of suppressing vortex induced vibration. Based on an idea of tubercles at the leading edge of a whale flipper which improve stall characteristics, a new device for reduction of fluctuating lift acting on a Riser Pipe is developed. As a result, the fluctuating lift acting on the stationary cylinder with the tubercles is reduced by 89% from the normal cylinder. In addition, at a mass damping parameter of 1.3, the maximum amplitude of the cylinder with the tubercles is one sixth as much as that of the normal cylinder.
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ship based co2 injection into subseabed geological formations using a flexible Riser Pipe pickup system
Energy Procedia, 2013Co-Authors: Naoki Nakazawa, Kyozo Kikuchi, Kenichi Ishii, Takumi Yamaguchi, Makoto Ohta, Masahiko OzakiAbstract:Abstract This report presents details of one aspect, namely, the flexible Riser Pipe pickup system, of a proposed ship-based carbon dioxide capture and storage (CCS) method. The liquefied CO 2 (LCO 2 ) to be sequestered is directly injected into subseabed geological formations through a flexible Riser Pipe using injection facilities contained onboard an LCO 2 carrier ship. The flexible Riser Pipe remains on the seabed, one end attached to the injection wellhead, until the other end is hoisted up and connected to the (dynamic positioning system (DPS)-controlled) LCO 2 carrier ship arriving at the ocean injection site. This proposed system has various advantages over the use of stationary sea surface structures for ship mooring and CO 2 injection: i) no need for stationary sea surface structures, e.g., ship-mooring-buoy or platform; ii) simplifies ship handling, especially in rougher sea states; and iii) the flexible Riser Pipe can remain on the seabed in rough seas. Details of a pickup buoy system for retrieving the Riser from the seabed and the structure of the flexible Riser Pipe are presented in this paper. The Riser pickup system consists basically of shipboard equipment such as a coupling valve, crane, winches and A-frame and offshore equipment such as a pickup buoy, pickup float, messenger line, sinker and pickup wire rope. The flexible Riser Pipe, outer diameter of 309 mm, was designed with due consideration of the stresses encountered with repeated retrievals from the seabed.
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Offshore Operational Availability of Onboard Direct Injection of CO2 into Sub-seabed Geological Formations
Energy Procedia, 2013Co-Authors: Tsuyoshi Miyazaki, Makoto Ohta, Hiroyuki Osawa, Masami Matsuura, Masahiko OzakiAbstract:Abstract Offshore operational availability was investigated for the proposed handling system consisting of the carrier vessel equipped with dynamic positioning capability, on-board manual operation of picking-up the sea-surface float connected to the upstream end of the flexible Riser Pipe laid-dawn on sea floor. An offshore site was selected to collect the oceanographic off the southern part of Japan facing to the Pacific Ocean. The response amplitude operator of the proposed CO 2 carrier vessel was calculated based on 3-D Singularity Distribution Method. Based on the result of the interview survey with captains of research vessels which showed that for offshore operations a vessel's pitch motion and service deck wetness are dominant factors which define a vessel's operational availability, the RAO of the pitch and relative wave elevation was evaluated. The hull motions and the relative wave elevation in unidirectional irregular waves and in multidirectional irregular waves were calculated by a conventional method based on the seakeeping theory using the RAOs, the wave spectrum and the directional wave spectrum. Under the assumption that the operational availability of the proposed CO 2 carrier vessel is constrained by the pitch motion and the service deck wetness, the allowable upper limit values of the significant wave height were calculated by a conventional method based on the sea keeping theorem using the 1/10 maximum expected response value of pitch motion and the relative wave elevation evaluated in the above-mentioned calculation. The threshold value of operation availability was set at the pitch of 3.0 degrees and the relative wave elevation at the freeboard to the service deck, based on the result of the interview survey with captains of research vessels. Finally, the overall operational availability was estimated, on the assumption that the threshold value of operation availability was set at the pitch of 3.0 degrees and the relative wave elevation at the freeboard to the service deck. We concluded that the operational availability of the proposed CO 2 carrier vessel reaches a target value of nearly 90% for both full year and four seasons in the case that freeboard of service deck for offshore buoy picking-up operations set greater than 2.3 m as a service platform.
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influence of inside fluid motion on tension variation of a deep sea drilling Riser in disconnected mode
Journal of the Society of Naval Architects of Japan, 1999Co-Authors: Hironori Yasukawa, Masahiko Ozaki, Kozo IshidaAbstract:Influence of inside fluid mass which exists inside the Riser Pipe on tension variation of the deep sea drilling Riser in disconnected mode is investigated. A simple calculation method of the tension variation is proposed taking the inside mass motion into account based on the lumped mass method. This method is verified through the comparison with the tension variation and the Riser bottom displacement measured in a basin test using a Riser model. The influence of the inside mass on the tension variation is numerically investigated for deep sea drilling Risers with 3 different length using the calculation method. For the deep sea Riser over 2, 000 m length, the mass corresponding to about 50% of the total inside mass acts on the Riser top as the additional tension variation.
Christopher M. Reddy - One of the best experts on this subject based on the ideXlab platform.
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petroleum dynamics in the sea and influence of subsea dispersant injection during deepwater horizon
Proceedings of the National Academy of Sciences of the United States of America, 2017Co-Authors: Christopher M. Reddy, Jonas Gros, Scott A Socolofsky, Anusha L Dissanayake, Inok Jun, Lin Zhao, Michel C Boufadel, Samuel J AreyAbstract:Abstract During the Deepwater Horizon disaster, a substantial fraction of the 600,000–900,000 tons of released petroleum liquid and natural gas became entrapped below the sea surface, but the quantity entrapped and the sequestration mechanisms have remained unclear. We modeled the buoyant jet of petroleum liquid droplets, gas bubbles, and entrained seawater, using 279 simulated chemical components, for a representative day (June 8, 2010) of the period after the sunken platform’s Riser Pipe was pared at the wellhead (June 4–July 15). The model predicts that 27% of the released mass of petroleum fluids dissolved into the sea during ascent from the pared wellhead (1,505 m depth) to the sea surface, thereby matching observed volatile organic compound (VOC) emissions to the atmosphere. Based on combined results from model simulation and water column measurements, 24% of released petroleum fluid mass became channeled into a stable deep-water intrusion at 900- to 1,300-m depth, as aqueously dissolved compounds (∼23%) and suspended petroleum liquid microdroplets (∼0.8%). Dispersant injection at the wellhead decreased the median initial diameters of simulated petroleum liquid droplets and gas bubbles by 3.2-fold and 3.4-fold, respectively, which increased dissolution of ascending petroleum fluids by 25%. Faster dissolution increased the simulated flows of water-soluble compounds into biologically sparse deep water by 55%, while decreasing the flows of several harmful compounds into biologically rich surface water. Dispersant injection also decreased the simulated emissions of VOCs to the atmosphere by 28%, including a 2,000-fold decrease in emissions of benzene, which lowered health risks for response workers.
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floating oil covered debris from deepwater horizon identification and application
Environmental Research Letters, 2012Co-Authors: Catherine A Carmichael, Laura J. Linn, William M Graham, Samuel J Arey, Karin L Lemkau, Robert K Nelson, Christopher M. ReddyAbstract:The discovery of oiled and non-oiled honeycomb material in the Gulf of Mexico surface waters and along coastal beaches shortly after the explosion of Deepwater Horizon sparked debate about its origin and the oil covering it. We show that the unknown pieces of oiled and non-oiled honeycomb material collected in the Gulf of Mexico were pieces of the Riser Pipe buoyancy module of Deepwater Horizon. Biomarker ratios confirmed that the oil had originated from the Macondo oil well and had undergone significant weathering. Using the National Oceanic and Atmospheric Administration's records of the oil spill trajectory at the sea surface, we show that the honeycomb material preceded the front edge of the uncertainty of the oil slick trajectory by several kilometers. We conclude that the observation of debris fields deriving from damaged marine materials may be incorporated into emergency response efforts and forecasting of coastal impacts during future offshore oil spills, and ground truthing predicative models.
Jonas Gros - One of the best experts on this subject based on the ideXlab platform.
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petroleum dynamics in the sea and influence of subsea dispersant injection during deepwater horizon
Proceedings of the National Academy of Sciences of the United States of America, 2017Co-Authors: Christopher M. Reddy, Jonas Gros, Scott A Socolofsky, Anusha L Dissanayake, Inok Jun, Lin Zhao, Michel C Boufadel, Samuel J AreyAbstract:Abstract During the Deepwater Horizon disaster, a substantial fraction of the 600,000–900,000 tons of released petroleum liquid and natural gas became entrapped below the sea surface, but the quantity entrapped and the sequestration mechanisms have remained unclear. We modeled the buoyant jet of petroleum liquid droplets, gas bubbles, and entrained seawater, using 279 simulated chemical components, for a representative day (June 8, 2010) of the period after the sunken platform’s Riser Pipe was pared at the wellhead (June 4–July 15). The model predicts that 27% of the released mass of petroleum fluids dissolved into the sea during ascent from the pared wellhead (1,505 m depth) to the sea surface, thereby matching observed volatile organic compound (VOC) emissions to the atmosphere. Based on combined results from model simulation and water column measurements, 24% of released petroleum fluid mass became channeled into a stable deep-water intrusion at 900- to 1,300-m depth, as aqueously dissolved compounds (∼23%) and suspended petroleum liquid microdroplets (∼0.8%). Dispersant injection at the wellhead decreased the median initial diameters of simulated petroleum liquid droplets and gas bubbles by 3.2-fold and 3.4-fold, respectively, which increased dissolution of ascending petroleum fluids by 25%. Faster dissolution increased the simulated flows of water-soluble compounds into biologically sparse deep water by 55%, while decreasing the flows of several harmful compounds into biologically rich surface water. Dispersant injection also decreased the simulated emissions of VOCs to the atmosphere by 28%, including a 2,000-fold decrease in emissions of benzene, which lowered health risks for response workers.
Catherine A Carmichael - One of the best experts on this subject based on the ideXlab platform.
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floating oil covered debris from deepwater horizon identification and application
Environmental Research Letters, 2012Co-Authors: Catherine A Carmichael, Laura J. Linn, William M Graham, Samuel J Arey, Karin L Lemkau, Robert K Nelson, Christopher M. ReddyAbstract:The discovery of oiled and non-oiled honeycomb material in the Gulf of Mexico surface waters and along coastal beaches shortly after the explosion of Deepwater Horizon sparked debate about its origin and the oil covering it. We show that the unknown pieces of oiled and non-oiled honeycomb material collected in the Gulf of Mexico were pieces of the Riser Pipe buoyancy module of Deepwater Horizon. Biomarker ratios confirmed that the oil had originated from the Macondo oil well and had undergone significant weathering. Using the National Oceanic and Atmospheric Administration's records of the oil spill trajectory at the sea surface, we show that the honeycomb material preceded the front edge of the uncertainty of the oil slick trajectory by several kilometers. We conclude that the observation of debris fields deriving from damaged marine materials may be incorporated into emergency response efforts and forecasting of coastal impacts during future offshore oil spills, and ground truthing predicative models.