Modeling Subsurface Dispersant Applications for Response Planning and Preparation

ABSTRACT The increase in oil and gas development activity at increasing water depths has highlighted the need for modeling tools to evaluate the unique aspects of accidental deepwater releases, one aspect being the need to assess the impact of subsurface dispersant application to a deepwater blowout. In response to this need, the effect of subsurface dispersant application has been implemented within RPS ASA's blowout model OILMAPDeep. OILMAPDeep was developed to simulate deepwater blowout releases; it predicts the evolution and characteristics of the subsurface plume and estimates the oil droplet size distribution associated with the release. The droplet size distribution dictates the vertical transport of oil within the water column, and impacts the relative volume anticipated to either surface or remain trapped in the water column. Droplet sizes are primarily a function of the energy of the release and the oil-water interfacial tension. The energy of the release is characterized by a reference velocity, typically the exit velocity, and the oil-water interfacial tension as a function of the oil properties. Dispersants mixed with oil reduce the oil-water interfacial tension, which in turn reduces the droplet sizes associated with treated releases serving to delay or eliminate surfacing oil. The present model implementation takes advantage of recent studies that have quantitatively assessed the relationship between the dispersant to oil ratio and surface tension. Here we present a background of the OILMAPDeep module, the governing physical processes of droplet formation, and the relationship between dispersant-to-oil ratio (DOR) and droplet size formation as characterized in the model. A description of the model implementation including model inputs and outputs are provided. Furthermore a set of scenarios are presented that demonstrate the model's capabilities for planning and preparing response activities in the event of a potential oil well blowout. This paper shows how the implementation of subsurface dispersant application within OILMAPDeep provides an effective means of evaluating potential response activities associated with subsurface dispersant application to a deepwater blowout. This includes evaluating the effect of subsurface dispersant application on droplet size distribution, and the ultimate impact on the timing, location and the relative volume of surfacing oil.

Download Full-text

Effect of Shear and Water Cut on Phase Inversion and Droplet Size Distribution in Oil–Water Flow

Journal of Energy Resources Technology ◽

10.1115/1.4041661 ◽

2018 ◽

Vol 141 (3) ◽

Cited By ~ 1

Author(s):

Mo Zhang ◽

Ramin Dabirian ◽

Ram S. Mohan ◽

Ovadia Shoham

Keyword(s):

Size Distribution ◽

Droplet Size ◽

Phase Inversion ◽

Droplet Size Distribution ◽

Continuous Phase ◽

Dispersed Phase ◽

Water Emulsion ◽

Inversion Region ◽

Oil Water ◽

Water Cut

Oil–water dispersed flow occurs commonly in the petroleum industry during the production and transportation of crudes. Phase inversion occurs when the dispersed phase grows into the continuous phase and the continuous phase becomes the dispersed phase caused by changes in the composition, interfacial properties, and other factors. Production equipment, such as pumps and chokes, generates shear in oil–water mixture flow, which has a strong effect on phase inversion phenomena. The objective of this paper is to investigate the effects of shear intensity and water cut (WC) on the phase inversion region and also the droplet size distribution. A state-of-the-art closed-loop two phase (oil–water) flow facility including a multipass gear pump and a differential dielectric sensor (DDS) is used to identify the phase inversion region. Also, the facility utilizes an in-line droplet size analyzer (a high speed camera), to record real-time videos of oil–water emulsion to determine the droplet size distribution. The experimental data for phase inversion confirm that as shear intensity increases, the phase inversion occurs at relatively higher dispersed phase fractions. Also the data show that oil-in-water emulsion requires larger dispersed phase volumetric fraction for phase inversion as compared with that of water-in-oil emulsion under the same shear intensity conditions. Experiments for droplet size distribution confirm that larger droplets are obtained for the water continuous phase, and increasing the dispersed phase volume fraction leads to the creation of larger droplets.

Download Full-text

Droplet Size Distribution of Oil-Water Emulsions by Confocal Laser Scanning Microscopy

ACS Symposium Series - Particle Sizing and Characterization ◽

10.1021/bk-2004-0881.ch005 ◽

2004 ◽

pp. 75-88 ◽

Cited By ~ 1

Author(s):

José M. Benito ◽

Guillermo Ríos ◽

Carmen Pazos ◽

José Coca

Keyword(s):

Size Distribution ◽

Confocal Laser Scanning Microscopy ◽

Droplet Size ◽

Laser Scanning ◽

Droplet Size Distribution ◽

Laser Scanning Microscopy ◽

Confocal Laser Scanning ◽

Scanning Microscopy ◽

Confocal Laser ◽

Oil Water

Download Full-text

A Comprehensive Approach from Interfacial to Bulk Properties of Legume Protein-Stabilized Emulsions

Fluids ◽

10.3390/fluids4020065 ◽

2019 ◽

Vol 4 (2) ◽

pp. 65 ◽

Cited By ~ 2

Author(s):

Manuel Félix ◽

Alberto Romero ◽

Cecilio Carrera-Sanchez ◽

Antonio Guerrero

Keyword(s):

Rheological Properties ◽

Size Distribution ◽

Droplet Size ◽

Electrostatic Interactions ◽

Ph Value ◽

Droplet Size Distribution ◽

Interfacial Properties ◽

Industrial Applications ◽

Droplet Sizes ◽

Legume Protein

The correlation between interfacial properties and emulsion microstructure is a topic of special interest that has many industrial applications. This study deals with the comparison between the rheological properties of oil-water interfaces with adsorbed proteins from legumes (chickpea or faba bean) and the properties of the emulsions using them as the only emulsifier, both at microscopic (droplet size distribution) and macroscopic level (linear viscoelasticity). Two different pH values (2.5 and 7.5) were studied as a function of storage time. Interfaces were characterized by means of dilatational and interfacial shear rheology measurements. Subsequently, the microstructure of the final emulsions obtained was evaluated thorough droplet size distribution (DSD), light scattering and rheological measurements. Results obtained evidenced that pH value has a strong influence on interfacial properties and emulsion microstructure. The best interfacial results were obtained for the lower pH value using chickpea protein, which also corresponded to smaller droplet sizes, higher viscoelastic moduli, and higher emulsion stability. Thus, results put forward the relevance of the interfacial tension values, the adsorption kinetics, the viscoelastic properties of the interfacial film, and the electrostatic interactions among droplets, which depend on pH and the type of protein, on the microstructure, rheological properties, and stability of legume protein-stabilized emulsions.

Download Full-text

Modeling of oil–water separation efficiency in three-phase separators: Effect of emulsion rheology and droplet size distribution

Chemical Engineering Research and Design ◽

10.1016/j.cherd.2020.02.022 ◽

2020 ◽

Vol 159 ◽

pp. 278-290 ◽

Cited By ~ 2

Author(s):

Lanre M. Oshinowo ◽

Regis D. Vilagines

Keyword(s):

Size Distribution ◽

Droplet Size ◽

Separation Efficiency ◽

Droplet Size Distribution ◽

Water Separation ◽

Three Phase ◽

Oil Water Separation ◽

Oil Water ◽

Emulsion Rheology

Download Full-text

Fluid Flow Phenomena and Droplet Size Distribution Along the Feed Spreader of Large Oil/Water Tank Separators

Volume 1: Symposia, Parts A, B and C ◽

10.1115/fedsm2009-78414 ◽

2009 ◽

Author(s):

Jose G. Severino ◽

Luis E. Gomez ◽

Steve J. Leibrandt ◽

Ram S. Mohan ◽

Ovadia Shoham

Keyword(s):

Size Distribution ◽

Droplet Size ◽

Separation Efficiency ◽

Droplet Size Distribution ◽

Separation Performance ◽

Water Tank ◽

Water Dispersion ◽

Flow Phenomena ◽

Oil Water ◽

The Impact

Large gravity separation tanks play an essential role in crude oil production in many fields worldwide. These tanks are used to separate water from an oil-rich stream before safely returning it to the environment. The oil/water dispersion enters the tanks through a feed spreader consisting of an array of pipes with small effluent nozzles. A major challenge is being able to predict oil/water dispersion distribution along the spreader as well as, the maximum water droplet size exiting through the effluent nozzles, under a given set of conditions. The capacity of the studied tank is 80,000 barrels (12,719 m3). Current feed stream is about 60,000 bpd (9,540 m3/day) of wet crude containing about 20% water by volume. A significant increase in flow rates and water volume fraction is anticipated [7], as more wells are added and existing ones mature. This work is aimed at investigating the separation performance of these tanks under current and future flow conditions; focusing primarily on the flow phenomena and droplet size distribution inside the spreader. The main objective is then to identify the impact of the spreader’s geometry and piping configuration on flow behavior and tank’s separation efficiency. The final product provides key information needed for mechanistic modeling the tank separation performance and optimizing tank components’ design. The feed spreader is simulated using Computational Fluid Dynamics (CFD) to assess oil/water flow distribution inside the network. Droplet size distribution along branch-pipes effluent nozzles in, including droplet breakup and coalescence has been studied using the Gomez mechanistic model [2] with input from CFD results. An experimental investigation of the spreader using a scaled prototype was also conducted to better understand flow phenomena and verify the CFD models. Results confirm the occurrence of significant maldistribution of the water and oil phases along the spreader that could impair separation efficiency.

Download Full-text

Aerosol Transmission of SARS-CoV-2: Physical Principles and Implications

Frontiers in Public Health ◽

10.3389/fpubh.2020.590041 ◽

2020 ◽

Vol 8 ◽

Author(s):

Michael C. Jarvis

Keyword(s):

Size Distribution ◽

Droplet Size ◽

Aerosol Particles ◽

Droplet Size Distribution ◽

Research Areas ◽

Droplet Sizes ◽

The Mean ◽

Uv Lamps ◽

Physical Principles ◽

Aerosol Form

Evidence has emerged that SARS-CoV-2, the coronavirus that causes COVID-19, can be transmitted airborne in aerosol particles as well as in larger droplets or by surface deposits. This minireview outlines the underlying aerosol science, making links to aerosol research in other disciplines. SARS-CoV-2 is emitted in aerosol form during normal breathing by both asymptomatic and symptomatic people, remaining viable with a half-life of up to about an hour during which air movement can carry it considerable distances, although it simultaneously disperses. The proportion of the droplet size distribution within the aerosol range depends on the sites of origin within the respiratory tract and on whether the distribution is presented on a number or volume basis. Evaporation and fragmentation reduce the size of the droplets, whereas coalescence increases the mean droplet size. Aerosol particles containing SARS-CoV-2 can also coalesce with pollution particulates, and infection rates correlate with pollution. The operation of ventilation systems in public buildings and transportation can create infection hazards via aerosols, but provides opportunities for reducing the risk of transmission in ways as simple as switching from recirculated to outside air. There are also opportunities to inactivate SARS-CoV-2 in aerosol form with sunlight or UV lamps. The efficiency of masks for blocking aerosol transmission depends strongly on how well they fit. Research areas that urgently need further experimentation include the basis for variation in droplet size distribution and viral load, including droplets emitted by “superspreader” individuals; the evolution of droplet sizes after emission, their interaction with pollutant aerosols and their dispersal by turbulence, which gives a different basis for social distancing.

Download Full-text

A New Mechanism of Droplet Size Distribution Broadening during Diffusional Growth

Journal of the Atmospheric Sciences ◽

10.1175/jas-d-12-0182.1 ◽

2013 ◽

Vol 70 (7) ◽

pp. 2051-2071 ◽

Cited By ~ 22

Author(s):

Alexei Korolev ◽

Mark Pinsky ◽

Alex Khain

Keyword(s):

Size Distribution ◽

Droplet Size ◽

Initial Conditions ◽

Droplet Size Distribution ◽

Cloud Base ◽

Diffusional Growth ◽

Cloud Droplets ◽

Droplet Concentration ◽

Droplet Sizes ◽

Precipitation Formation

Abstract A new mechanism has been developed for size distribution broadening toward large droplet sizes. This mechanism may explain the rapid formation of large cloud droplets, which may subsequently trigger precipitation formation through the collision–coalescence process. The essence of the new mechanism consists of a sequence of mixing events between ascending and descending parcels. When adiabatically ascending and descending parcels having the same initial conditions at the cloud base arrive at the same level, they will have different droplet sizes and temperatures, as well as different supersaturations. Isobaric mixing between such parcels followed by further ascents and descents enables the enhanced growth of large droplets. The numerical simulation of this process suggests that the formation of large 30–40-μm droplets may occur within 20–30 min inside a shallow adiabatic stratiform layer. The dependencies of the rate of the droplet size distribution broadening on the intensity of the vertical fluctuations, their spatial amplitude, rate of mixing, droplet concentration, and other parameters are considered here. The effectiveness of this mechanism in different types of clouds is discussed.

Download Full-text

Effects of Varying Liquid Fuel and Air Co-Flow Rates on Spray Characterisation of an Annular Co-Flow Spray Burner

Volume 4B: Combustion, Fuels, and Emissions ◽

10.1115/gt2019-90989 ◽

2019 ◽

Cited By ~ 1

Author(s):

R. A. Alsulami ◽

S. Nates ◽

W. Wang ◽

S. H. Won ◽

Bret Windom

Keyword(s):

Size Distribution ◽

Droplet Size ◽

Liquid Fuel ◽

Air Flow ◽

Droplet Size Distribution ◽

Droplet Breakup ◽

Flame Stability ◽

Flow Rates ◽

Droplet Sizes ◽

The Impact

Abstract Development of efficient and clean combustion systems requires the understanding of all the processes experienced by a complex liquid fuel in IC engines, such as atomization, vaporization, turbulent mixing, and combustion. Many of these processes are interconnected; the atomization process, which leads to various droplet sizes can enhance or diminish the vaporization rate of the liquid fuel and consequently impact the energy conversion process. Furthermore, the combustion/flame stability of liquid-fueled gas turbine can be influenced by the fuel and the air co-flow rates delivered in the engine. Increasing the fuel and/or air flow rates can enhance droplet breakup and the turbulence of the flow, and as a result sway the droplet size distribution of the spray. This work focuses on investigating the impact of varying the fuel and air flow rates on the spray atomization (e.g. droplet size distribution) of an Annular Co-Flow Spray Burner. This was explored by measuring droplet sizes and velocities of the spray at different radial and axial positions of n-heptane fuel under nonreacting conditions. In addition, the turbulence intensity and the liquid spray droplet distribution were quantified for different fuel and air flow rate conditions. The measurements were obtained by using a Phase Doppler Particle Analyzer/Laser Doppler Velocimeter (PDPA/LDV) at P = 1 atm and T = 298 K. Moreover, the Sauter Mean Diameters for different flow conditions are predicted, using an established correlations, and compared to PDPA/LDV measurements. The results provided a fair understanding of the influence of varying the fuel and air flow rates on the droplet sizes, velocity, and turbulent intensity. Furthermore, the results presented here will support future work that will focus on unraveling the role of phase change on flame stability.

Download Full-text