DeepSpill––Field Study of a Simulated Oil and Gas Blowout in Deep Water

Johansen, Øistein; Rye, Henrik; Cooper, Cortis

doi:10.1016/s1353-2561(02)00123-8

Cited by 156 publications

(102 citation statements)

References 4 publications

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“…The BPM predicts a trap depth of 740 m, which is very close to the predicted trap depth of 745 m for the CDOG model. For the case with marine diesel in a stronger current (not shown), the BPM predicts a trap depth of 795 m, which lies between predictions from Johansen et al [67] of 674 m and Chen and Yapa [27] of 824 m. The trajectories of the bubbles above the separation height agree well with the acoustic measurements, with the bubbles rising to similar heights as the observations and following the main trends of the acoustic data. Differences between the model trajectories and the acoustic signals are similar across all models (BPM, DeepBlow, and CDOG) and can be attributed to using crossflow information from a single ADCP in the vicinity of the measurements which may not represent the true velocities along the bubble trajectories.…”

Section: Multiphase Plume Validation: Feld Experimentssupporting

confidence: 76%

“…The experiment simulated an accidental oil-well blowout and involved the release of natural gas (approximately 99% methane) together with seawater, marine diesel, or crude oil from a multiphase discharge at 844 m depth [67]. The primary subsurface observations were of the oil droplet and bubble size distribution at the release using cameras on a remotely operated vehicle (ROV) and of the distribution of gas bubbles in the water column from acoustic backscatter using the echo sounder on the support vessel.…”

Section: Multiphase Plume Validation: Feld Experimentsmentioning

confidence: 99%

“…13, we present results for a release rate of 0:7 Nm 3 =s of natural gas and 60 m 3 =h of seawater, which formed a bubbly jet of gas and water. The colored blocks in the figure are the acoustic backscatter intensities measured from the echo sounder [67,68]. The crossflow data are taken from a moored acoustic Doppler current profiler (ADCP) that was recording during the experiments.…”

Section: Multiphase Plume Validation: Feld Experimentsmentioning

confidence: 99%

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Integral models for bubble, droplet, and multiphase plume dynamics in stratification and crossflow

2018

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We present the development and validation of a numerical modeling suite for bubble and droplet dynamics of multiphase plumes in the environment. This modeling suite includes real-fluid equations of state, Lagrangian particle tracking, and two different integral plume models: an Eulerian model for a double-plume integral model in quiescent stratification and a Lagrangian integral model for multiphase plumes in stratified crossflows. Here, we report a particle tracking algorithm for dispersed-phase particles within the Lagrangian integral plume model and a comprehensive validation of the Lagrangian plume model for single-and multiphase buoyant jets. The model utilizes literature values for all entrainment and spreading coefficients and has one remaining calibration parameter j, which reduces the buoyant force of dispersed phase particles as they approach the edge of a Lagrangian plume element, eventually separating from the plume as it bends over in a crossflow. We report the calibrated form j ¼ ½ðb À rÞ=b 4 , where b is the plume halfwidth, and r is the distance of a particle from the plume centerline. We apply the validated modeling suite to simulate two test cases of a subsea oil well blowout in a stratificationdominated crossflow. These tests confirm that errors from overlapping plume elements in the Lagrangian integral model during intrusion formation for a weak crossflow are negligible for predicting intrusion depth and the fate of oil droplets in the plume. The Lagrangian integral model has the added advantages of being able to account for entrainment from an arbitrary crossflow, predict the intrusion of small gas bubbles and oil droplets when appropriate, and track the pathways of individual bubbles and droplets after they separate from the main plume or intrusion layer.

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Section: Multiphase Plume Validation: Feld Experimentssupporting

confidence: 76%

Section: Multiphase Plume Validation: Feld Experimentsmentioning

confidence: 99%

Section: Multiphase Plume Validation: Feld Experimentsmentioning

confidence: 99%

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Integral models for bubble, droplet, and multiphase plume dynamics in stratification and crossflow

2018

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“…High-frequency (>10 kHz) acoustic methods utilizing vesselmounted echo sounders, such as the ones used in this work, are frequently used to image marine organisms in the water column (11) but have also been used to observe controlled experimental discharges of oil and gas mixtures in the Norwegian Sea (12). One of the main advantages of using high-frequency shipboard echo sounders is their ability to generate a synoptic view of the ocean directly beneath the ship, creating an acoustic backscatter "map" extending from the ocean surface to the ocean bottom along the ship's track at normal ship transit speeds.…”

mentioning

confidence: 99%

“…Acoustic observations from all four NOAA ships made with the lower-frequency echo sounders (12,18, and 38 kHz) often indicated the presence of methane seeps rising from the seafloor (13), a capability that was later exploited during wellhead integrity testing after the well was capped in mid-July (14). Gas bubbles in seawater strongly scatter sound, with scattering cross-sections that are several orders of magnitude higher than a similarly sized oil droplet at frequencies close to the mechanical resonance of the bubble (15).…”

mentioning

confidence: 99%

Estimating oil concentration and flow rate with calibrated vessel-mounted acoustic echo sounders

Weber

Robertis

Greenaway

et al. 2011

Proc. Natl. Acad. Sci. U.S.A.

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As part of a larger program aimed at evaluating acoustic techniques for mapping the distribution of subsurface oil and gas associated with the Deepwater Horizon -Macondo oil spill, observations were made on June 24 and 25, 2010 using vessel-mounted calibrated single-beam echo sounders on the National Oceanic and Atmospheric Administration ship Thomas Jefferson . Coincident with visual observations of oil at the sea surface, the 200-kHz echo sounder showed anomalously high-volume scattering strength in the upper 200 m on the western side of the wellhead, more than 100 times higher than the surrounding waters at 1,800-m distance from the wellhead, and weakening with increasing distance out to 5,000 m. Similar high-volume scattering anomalies were not observed at 12 or 38 kHz, although observations of anomalously low-volume scattering strength were made in the deep scattering layer at these frequencies at approximately the same locations. Together with observations of ocean currents, the acoustic observations are consistent with a rising plume of small (< 1-mm radius) oil droplets. Using simplistic but reasonable assumptions about the properties of the oil droplets, an estimate of the flow rate was made that is remarkably consistent with those made at the wellhead by other means. The uncertainty in this acoustically derived estimate is high due to lack of knowledge of the size distribution and rise speed of the oil droplets. If properly constrained, these types of acoustic measurements can be used to rapidly estimate the flow rate of oil reaching the surface over large temporal and spatial scales.

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Split-beam echo sounder observations of natural methane seep variability in the northern Gulf of Mexico

Jerram

Weber

Beaudoin

2015

Geochem. Geophys. Geosyst.

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A method for positioning and characterizing plumes of bubbles from marine gas seeps using an 18 kHz scientific split-beam echo sounder (SBES) was developed and applied to acoustic observations of plumes of presumed methane gas bubbles originating at approximately 1400 m depth in the northern Gulf of Mexico. A total of 161 plume observations from 27 repeat surveys were grouped by proximity into 35 clusters of gas vent positions on the seafloor. Profiles of acoustic target strength per vertical meter of plume height were calculated with compensation for both the SBES beam pattern and the geometry of plume ensonification. These profiles were used as indicators of the relative fluxes and fates of gas bubbles acoustically observable at 18 kHz and showed significant variability between repeat observations at time intervals of 1 h-7.5 months. Active gas venting was observed during approximately one third of the survey passes at each cluster. While gas flux is not estimated directly in this study owing to lack of bubble size distribution data, repeat surveys at active seep sites showed variations in acoustic response that suggest relative changes in gas flux of up to 1 order of magnitude over time scales of hours. The minimum depths of acoustic plume observations at 18 kHz averaged 875 m and frequently coincided with increased amplitudes of acoustic returns in layers of biological scatterers, suggesting acoustic masking of the gas bubble plumes in these layers. Minimum plume depth estimates were limited by the SBES field of view in only five instances.

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DeepSpill––Field Study of a Simulated Oil and Gas Blowout in Deep Water

Cited by 156 publications

References 4 publications

Integral models for bubble, droplet, and multiphase plume dynamics in stratification and crossflow

Integral models for bubble, droplet, and multiphase plume dynamics in stratification and crossflow

Estimating oil concentration and flow rate with calibrated vessel-mounted acoustic echo sounders

Split-beam echo sounder observations of natural methane seep variability in the northern Gulf of Mexico

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