Study on the Yield-Thixotropy of Waxy Crude Oil under Uniform Sweeping Rate of Share Rate

2013 ◽  
Vol 706-708 ◽  
pp. 297-300
Author(s):  
Li Ping Guo ◽  
Mo Xiao Liu ◽  
Gui Ying Xu
Keyword(s):  
Crude Oil ◽  
Time Dependent ◽  
Waxy Crude Oil ◽  
Waxy Crude ◽  
Different Types ◽  
Wax Crystal ◽  
Thixotropic Behavior ◽  
Important Time ◽  
Relationship Of ◽  
The Relationship

Yield-thixotropy is an important time dependent rheological behavior of gelled waxy crude oil. In order to study the yield-thixotropic behavior of gelled waxy crude oil under cyclic shearing of linear increasing and decreasing of shear rate, four different types of waxy crude oil were studied experimentally by using RS150H rheometer. It is found that because the recovery rate of wax crystal structure is slow, study should be focus on the first loop. At a certain temperature, the hysteresis loop moves away from the share rate axis and the area of the loop becomes larger with increased rate of share rate sweep; and vice versa, the loop moves toward the share rate axis and the area of the loop becomes smaller with decreased rate of share rate sweep. And the yield stress is also reduced and the yielding time increased with decreased rate of share rate sweep. In addition, based on the experimental results an empirical correlation is developed to describe the relationship of yielding time and rate of share rate sweep.

scholarly journals The studies of thixotropic properties of waxy crude oil from White Tiger and Rong fields

1996 ◽  
Vol 18 (4) ◽  
pp. 23-28
Author(s):  
Ha Van Bich
Keyword(s):  
Crude Oil ◽  
Time Dependent ◽  
Hyperbolic Functions ◽  
Waxy Crude Oil ◽  
Waxy Crude ◽  
Acceptable Accuracy ◽  
Dependent Behavior ◽  
White Tiger ◽  
Newtonian Liquids

As in production and transport of waxy crude oil, and as in practical rheological studies of non-Newtonian liquids, it is very important to find and characterize its thixotropic properties. There are some ways to study this phenomenon, but still existing equations can not quantifiably describe the time dependent behavior of thixotropic liquids with acceptable accuracy, using in this case an exponential or hyperbolic functions.

scholarly journals Pour point depression and flow improvement of waxy crude oil using polyethylene glycol esters of cashew nut shell liquid

2021 ◽  
Author(s):  
William Iheanyi Eke ◽  
Sampson Kofi Kyei ◽  
Ozioma Achugasim ◽  
Joseph Atubokiki Ajienka ◽  
Onyewuchi Akaranta
Keyword(s):  
Crude Oil ◽  
Pour Point ◽  
Crystal Morphology ◽  
Micro Structure ◽  
Waxy Crude Oil ◽  
Cashew Nut Shell Liquid ◽  
Waxy Crude ◽  
Cashew Nut ◽  
Wax Crystal ◽  
Cashew Nut Shell

AbstractWax crystallization and deposition is a major flow assurance problem in production and transportation of waxy crude oil. Conventional flow improvers are mainly high molecular weight synthetic polymers, many of which are eco-toxic. Bio-based flow improvers derived from natural products are promising as inexpensive, eco-friendly alternatives to existing products. In this study, natural cashew nut shell liquid (CNSL) extracted from waste shells of Anacardium occidentale was esterified with polyethylene glycol (PEG). CNSL derivative reduced the pour point of waxy crude oil by 12 °C at 1000 ppm. The effects of CNSL derivatives on wax crystal morphology and micro-structure were studied by cross-polarized microscopy. Micrographs were processed and analyzed with ImageJ software. Addition of CNSL derivatives to oil resulted in changes in wax crystal morphology and micro-structure evidenced by a reduction in average crystal Feret diameter and aspect ratio and increase in boundary fractal dimension, indicative of formation of increasing number of smaller, rounder crystals. Effect of the additives on flow properties of the waxy oil was determined using a co-axial cylinder rotational viscometer. Dynamic viscosity of oil at shear rate of 17 s−1 was reduced by 79.7–90.5%. CNSL-PEG esters show good prospects as low-cost additives for production, storage and pipeline transportation of waxy crude oil.

A Novel Method for Characterizing the Aggregation of Wax Crystals and An Improvement in Wax Deposition Modeling

2020 ◽  
Vol 142 (10) ◽  
Author(s):  
Zhihua Wang ◽  
Hankun Wang ◽  
Chaoliang Zhu ◽  
Zhenhua Rui ◽  
Yang Liu
Keyword(s):  
Fractal Dimension ◽  
Crude Oil ◽  
Aggregation Behavior ◽  
Wax Deposition ◽  
Waxy Crude Oil ◽  
Waxy Crude ◽  
Wax Crystal ◽  
Novel Method ◽  
Improved Model ◽  
Wax Crystals

Abstract The aggregation behavior and the subsequent deposition behavior of wax crystals own undesirable effects on the production and transportation of waxy crude oil. The understanding and prediction of these behaviors are essential to ensure economic and uninterrupted flow of waxy crude oil when the oil temperature decreases below the wax appearance temperature (WAT). In this paper, a novel method of fractal dimensional analysis was introduced to elucidate the aggregation behavior of wax crystals in different shear flow fields. The fractal methodology for characterizing wax crystal aggregation was then developed, and a blanket algorithm was introduced to compute the fractal dimension of the aggregated wax crystals. Considering the flow characteristics of waxy crude oil in a pipeline can be correlated with the shearing stress work, a modified wax deposition model focusing on shearing energy analysis was established. The results indicate that a quantitative interpretation of the wax crystal aggregation behavior can be realized using the fractal methodology. The aggregation behavior of the wax crystals is closely related to the temperature and shearing experienced by the waxy crude oil. The aggregation behavior will be intensified with decreasing temperature and shearing effect, and a wider fractal dimension distribution appears at lower temperatures when the same shear rate range is used. Furthermore, the improved model provides a method for discussing the effects of the operating conditions on wax deposition. The average relative deviation between the improved model prediction results and experimental results from the literature is 3.01–5.32%.

scholarly journals Rheological Investigation on the Effect of Shear and Time Dependent Behavior of Waxy Crude Oil

2014 ◽  
Vol 13 ◽  
pp. 02034
Author(s):  
A. Japper-Jaafar ◽  
P. Bhaskoro ◽  
M.Z. Sariman ◽  
R. Rozlee
Keyword(s):  
Crude Oil ◽  
Time Dependent ◽  
Waxy Crude Oil ◽  
Waxy Crude ◽  
Dependent Behavior

Time-Dependent Rheology of a Model Waxy Crude Oil with Relevance to Gelled Pipeline Restart†

2009 ◽  
Vol 23 (3) ◽  
pp. 1311-1315 ◽  
Author(s):  
Jules J. Magda ◽  
Husam El-Gendy ◽  
Kyeongseok Oh ◽  
Milind D. Deo ◽  
Alberto Montesi ◽  
...  
Keyword(s):  
Crude Oil ◽  
Time Dependent ◽  
Waxy Crude Oil ◽  
Waxy Crude

EXPERIMENTAL ANALYSIS OF THE FLOW START-UP OF GELLED WAXY CRUDE OIL IN A PIPELINE PREVIOUSLY SUBMITTED TO DIFFERENT PRESSURIZATIONS

2016 ◽  
Author(s):  
Gabriel Tanaka Nunes ◽  
Fernando Kroetz ◽  
Tainan Gabardo ◽  
Nezia de Rosso ◽  
Cezar Otaviano Ribeiro Negrao
Keyword(s):  
Crude Oil ◽  
Experimental Analysis ◽  
Waxy Crude Oil ◽  
Waxy Crude ◽  
Start Up

The role of shearing effect in evolution of the microscopic behavior of wax crystals

2021 ◽  
Author(s):  
Yuanhao Li ◽  
Jian Zhao ◽  
Hang Dong ◽  
Xiangrui Xi
Keyword(s):  
Crude Oil ◽  
Waxy Crude Oil ◽  
Waxy Crude ◽  
Dynamical Behaviors ◽  
Physical Phenomena ◽  
Wax Crystals

The microstructure and dynamical behaviors of wax crystals in waxy crude oil are the fundamental reasons for a series of physical phenomena in the process of transportation. In order to...

Relationship Between Different Types of Violence and Mental Health in High School Students From Northern Mexico

2021 ◽  
pp. 088626052110219
Author(s):  
Oscar Armando Esparza-Del Villar ◽  
Sarah Margarita Chavez-Valdez ◽  
Priscila Montañez-Alvarado ◽  
Marisela Gutiérrez-Vega ◽  
Teresa Gutiérrez-Rosado
Keyword(s):  
Mental Health ◽  
High School ◽  
High School Students ◽  
Partner Violence ◽  
Health Indicators ◽  
School Students ◽  
Social Violence ◽  
Different Types ◽  
Relationship Of ◽  
The Relationship

Different types of violence have been present in Mexico but there have been few studies that have analyzed their relationship with mental health in adolescents, especially in cities with high rates of social violence. It is important to compare different violence types and their relationship with mental health since not all relationships are the same. It appears that social violence has a stronger relationship with mental health, and for this reason it receives more attention, but other types of violence have a stronger relationship and do not receive as much attention. Chihuahua has been one of the most violent states in Mexico, and Juarez has been the most violent city in the world in 2009 and 2010. The purpose of the study is to compare the relationship of different types of violence (social, cyberbullying, partner violence, and child abuse and neglect) with mental health indicators (depression, anxiety, stress, self-esteem, and paranoid thoughts). There were 526 high school students, from the cities of Juarez ( n = 282) and Chihuahua ( n = 244). The mean age was 16.5 ( SD = 1.4) years and 50.6% reported being males. The relationships among the variables were analyzed using Pearson’s correlations and multiple linear regressions. Both cities that have experienced social violence like carjacking, kidnapping, and sexual assault, but they have very small or no relationships with mental health indicators. Other types of violence have stronger correlations. Our findings suggest that interventions should not focus only in preventing and dealing with social violence, but that other types of violence must also be addressed in adolescents.

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