Applying ultrasonic fields to separate water contained in medium-gravity crude oil emulsions and determining crude oil adhesion coefficients

Applying ultrasonic fields to separate water contained in medium-gravity crude oil emulsions and determining crude oil adhesion coefficients

Crude oil

Demulsification

Pipeline corrosion

Corrosion rate

Emulsions

Adhesion coefficients

Crude oil dewatering, water-in-oil emulsion

Pipe-form ultrasonic field tester

Water plus salt separation

Adhesion

PETROLEUM

WATER storage

ADHESION

EMULSIONS

PIEZOELECTRIC transducers

SALINE water conversion

ULTRASONIC transducers

Ostwald ripening

Oil field equipment

Corrosion prevention

Irradiation

Desalination

Ultrasonic testing

Ultrasonic transducers

Wastewater treatment

Separating produced water is a key part of production processing for most crude oils. It is required for quality reasons, and to avoid unnecessary transportation costs and prevent pipework corrosion rates caused by soluble salts present in the water. A complicating factor is that water is often present in crude oil in the form of emulsions. Experiments were performed to evaluate the performance of ultrasonic fields in demulsifying crude oil emulsions using novel pipe-form equipment. A horn-type piezoelectric ultrasonic transducer with a frequency of 20 kHz and power ranging from 80 W to 1000 W was used for experimental purposes. The influences of the intensity of ultrasonic fields, ultrasonic irradiation time, and the initial water content of crude oils were evaluated to establish the rate of water segregation from oil. The experiments applied ultrasonic-field intensities of 0.25 W/cm3, 0.5 W/cm3, 0.75 W/cm3 and 1 W/cm3 to synthetic emulsions with 10%, 15%, 20%, and 25% of the water in crude oil. Crude oil demulsification occurred for each ultrasonic field intensity tested for all the samples tested. Function β involving adhesion coefficients was expressed in terms of wave-field intensity and initial concentration of water in each of the three crude oil samples tested. The experiments demonstrated that despite the absence of any chemical demulsifier involved, water separation caused by applying ultrasonic fields was effective and occurred rapidly. As the intensity of the ultrasonic field applied increased, the amount of water segregated from crude oil also increased. Subjected to constant field intensity, higher initial water cuts (up to 15% or so) in the crude oil samples and higher ultrasonic irradiation times, resulted in greater segregation of water from crude oil in percentage terms. However, in samples with initial water cuts of 20+% long irradiation times (~5 min), resulted in a decline in water separation compared to 2-min tests. Ultrasonic field treatments offer commercially-viable and environmentally-friendly alternatives to treatments using chemical demulsifiers as they reduce desalination requirements of wastewater.

105303

70

Ultrasonics Sonochemistry

2021

Sadatshojaie, Ali

Wood, David A.

Jokar, Seyyed Mohammad

Rahimpour, Mohammad Reza

journalArticle

1350-4177

10.1016/j.ultsonch.2020.105303

https://www.sciencedirect.com/science/article/pii/S1350417720307112