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

2018 ◽  
Vol 141 (3) ◽  
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.

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

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.

Effects of the Dispersed Phase on Oil/Water Wax Deposition

2013 ◽  
Vol 135 (4) ◽  
Author(s):  
Pengyu Wang ◽  
Wei Wang ◽  
Jing Gong ◽  
Yuanxin Zhou ◽  
Wei Yang
Keyword(s):  
Particle Size ◽  
Crude Oil ◽  
Dispersed Phase ◽  
Wax Deposition ◽  
Waxy Crude Oil ◽  
Water Emulsion ◽  
Oil Emulsion ◽  
Wax Content ◽  
Oil Water ◽  
Water Cut

In the study of the foundation of the oil / water wax deposition experiment, the emulsification characteristics of crude oil emulsion with high wax content have gradually become the hot research area. In the current research of emulsification characteristics of oil/water emulsion, the attention has been focused on the study of the effects of water cut, stirring speed, particle size distribution on the viscosity of waxy crude oil emulsion in the experiment, in which heavy oil and simulated oil are adopted as the working fluids. In this study, the emulsion with different water cut and stirred by different speed was prepared under three different temperature conditions, the temperature above the wax appearance temperature (WAT), near the WAT, and below the WAT. The polarization microscope and rotary viscometer were applied to measure the effects of the particle size of the dispersed phase and waxy crystal distribution on the oil/water emulsion viscosity. The results suggest that preparing the temperature for crude oil emulsion with high wax content has an important influence on the emulsion microstructure. This study lays the foundation for further study of oil/water two phase dynamic wax deposition experiments.

Modeling Subsurface Dispersant Applications for Response Planning and Preparation

2014 ◽  
Vol 2014 (1) ◽  
pp. 933-948 ◽  
Author(s):  
Deborah Crowley ◽  
Daniel Mendelsohn ◽  
Nicole Whittier Mulanaphy ◽  
Zhengkai Li ◽  
Malcolm Spaulding
Keyword(s):  
Interfacial Tension ◽  
Water Column ◽  
Size Distribution ◽  
Droplet Size ◽  
Droplet Size Distribution ◽  
Relative Volume ◽  
Modeling Tools ◽  
Droplet Sizes ◽  
Oil Water ◽  
The Relationship

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.

Influence of Semicontinuous Processing on the Rheology and Droplet Size Distribution of Mayonnaise-like Emulsions

2009 ◽  
Vol 15 (4) ◽  
pp. 367-373 ◽  
Author(s):  
C. Bengoechea ◽  
M.L. López ◽  
F. Cordobés ◽  
A. Guerrero
Keyword(s):  
Size Distribution ◽  
Droplet Size ◽  
Flow Rate ◽  
Droplet Size Distribution ◽  
Egg Yolk ◽  
Continuous Phase ◽  
Agitation Speed ◽  
Viscosity Data ◽  
Pumping System ◽  
Oil In Water

Oil-in-water (o/w) emulsions stabilized by egg yolk, with a composition similar to those found in commercial mayonnaises or salad dressings, were processed in a semicontinuous device. This specially designed emulsification device consists of, basically, a vessel provided with an anchor impeller, where the continuous phase was initially placed; a pumping system that controls the addition of the oily phase; a rotor-stator unit, where the major breaking of the oily droplets takes place, and a recirculation system. The design allowed the introduction of a rotational rheometer to obtain viscosity data along the emulsification process. The most important advantages of this in-line emulsification device, when compared to discontinuous emulsification equipment, are the possibilities of recording viscosity data along the process and the higher values for the storage, G', and loss moduli, G'', of the resulting emulsions. The influence of egg yolk concentration, agitation speed, and flow rate over the rheological properties (G', G'') as well as droplet size distribution were investigated. Higher protein concentration, agitation speed and flow rate generally produce emulsions with higher G' and G'' values.

Droplet Formation Through Centrifugal Pumps for Oil-in-Water Dispersions

SPE Journal ◽  
2012 ◽  
Vol 18 (01) ◽  
pp. 172-178 ◽  
Author(s):  
Rosanel Morales ◽  
Eduardo Pereyra ◽  
Shoubo Wang ◽  
Ovadia Shoham
Keyword(s):  
Size Distribution ◽  
Centrifugal Pump ◽  
Droplet Size ◽  
Flow Rate ◽  
Droplet Size Distribution ◽  
Droplet Formation ◽  
Centrifugal Pumps ◽  
Mixture Flow ◽  
Pump Speed ◽  
Water Cut

Summary Droplet formation in oil/water flow through a centrifugal pump has been studied, experimentally and theoretically, for the first time. Droplet-size distribution at the pump outlet has been measured for water-continuous flow as a function of pump speed, mixture-flow rate, and water cut. The measured droplet-size distribution strongly depends on the pump speed: the higher the pump speed, the smaller the droplet size. Negligible effects of mixture-flow rate, water cut, and inlet droplet-size distribution have been observed. Turbulent breakup has been identified as the main mechanism for droplet formation. A mechanistic model is developed for the prediction of droplet-size distribution in a centrifugal pump, showing a fair agreement with the acquired experimental data.

Shear Effects on Phase Inversion in Oil-Water Flow

2015 ◽  
Author(s):  
Mo Zhang ◽  
Shoubo Wang ◽  
Ram S. Mohan ◽  
Ovadia Shoham ◽  
Haijing Gao
Keyword(s):  
Phase Inversion ◽  
Petroleum Industry ◽  
Continuous Phase ◽  
Production Equipment ◽  
Current Phase ◽  
Dispersed Phase ◽  
Gear Pump ◽  
Water Mixture ◽  
Mixture Flow ◽  
Oil Water

Oil-water dispersed flow, in which one of the phases either water or oil is dispersed into the other phase, which is the continuous phase, occurs commonly in 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, generate shear in oil-water mixture flow, which has a strong effect on phase inversion phenomena. In this study, based on the newly acquired data on a gear pump, the relationship between phase inversion region and shear intensity are discussed and the limitation of current phase inversion prediction model is presented.

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