Wax Deposition in Pipelines: Flow-Loop Experiments and Investigations on a Novel Approach

2008 ◽  
Author(s):  
Benallal Amine ◽  
Philippe Maurel ◽  
Jean Francois Agassant ◽  
Myriam Darbouret ◽  
Guillaume Avril ◽  
...  
Keyword(s):  
Wax Deposition ◽  
Flow Loop ◽  
Novel Approach

Experimental Investigation of Wax Deposition at Different Deposit Locations Through a Detachable Flow Loop Apparatus

2014 ◽  
Author(s):  
Si Li ◽  
Qiyu Huang ◽  
Wenda Wang ◽  
Changhui Wang ◽  
Zhenjun Ding
Keyword(s):  
Temperature Interval ◽  
Flow Rate ◽  
Test Section ◽  
Measurement Techniques ◽  
Operating Conditions ◽  
Temperature Fields ◽  
Wax Deposition ◽  
Flow Loop ◽  
Deposit Thickness ◽  
Wax Content

Wax deposition has always been a focus in the research field of flow assurance. Operating conditions are among the predominant factors that control the deposition rate and the nature of the formed deposits. However, the disadvantages of the available wax thickness measurement techniques applied to laboratory flow loops limit deeper studies on this issue. In this work, the effects of operating conditions, including temperature interval and flow rate, on wax deposition at different deposit locations are experimentally studied using a detachable flow loop apparatus. With the detachable test section, it is achievable to obtain the thickness and the wax content profiles of the deposit as functions of axial location and time. The temperature fields in the test section under both temperature intervals are simulated with CFD software FLUENT to provide more information for the analysis of deposition process. As the results manifest, the low temperature interval tends to intensify deposition, relating to the inner temperature field and wax precipitated property of the oil. The larger flow rate leads to a growth in the deposit thickness under the laminar flow regime and brings about a distinct rise in the wax content of deposit at inlet. In addition, the increase in deposit thickness and wax content indicates the phenomenon of deposit aging, and the wax deposit layer is thinner but with higher wax content at the inlet, due to the strong flow scour.

scholarly journals Review of the Factors that Influence the Condition of Wax Deposition in Subsea Pipelines

2018 ◽  
Vol 3 (1) ◽  
pp. 1-8 ◽  
Author(s):  
Koh Junyi ◽  
Nurul Hasan
Keyword(s):  
Crude Oil ◽  
Residence Time ◽  
Flow Rate ◽  
Temperature Difference ◽  
Wax Deposition ◽  
Flow Loop ◽  
New Models ◽  
Wax Content ◽  
The Difference ◽  
Deep Depth

When crude oil is transported via sub-sea pipeline, the temperature of the pipeline decreases at a deep depth which causes a difference in temperature with the crude oil inside. This causes the crude oil to dissipate its heat to the surrounding until thermal equilibrium is achieved. This is also known as the cloud point where wax begins to precipitate and solidifies at the walls of the pipeline which obstruct the flow of fluid. The main objective of this review is to quantify the factors that influence wax deposition such as temperature difference between the wall of the pipeline and the fluid flowing within, the flow rate of the fluid in the pipeline and residence time of the fluid in the pipeline. It is found the main factor that causes wax deposition in the pipeline is the difference in temperature between the petroleum pipeline and the fluid flowing within. Most Literature deduces that decreasing temperature difference results in lower wax content deposited on the wall of the pipeline. The wax content increases with rising flow rate. As for the residence time, the amount of deposited wax initially increases when residence time increases until it reaches a peak value and gradually decreases. Flow-loop system and cold finger apparatus were used in literature investigations to determine the trends above. Three new models are generated through a regression analysis based on the results from other authors. These new models form a relationship between temperature difference, flow rate, residence time and Reynolds number with wax deposition. These models have high values of R-square and adjusted R-square which demonstrate the reliability of these models.

Flow Rate Effect on Wax Deposition Behavior in Single-Phase Laminar Flow

2018 ◽  
Vol 141 (3) ◽  
Author(s):  
Pan-Sang Kang ◽  
Ji Yu Hwang ◽  
Jong-Se Lim
Keyword(s):  
Laminar Flow ◽  
Flow Rate ◽  
Single Phase ◽  
Measured Data ◽  
Model Parameters ◽  
Wax Deposition ◽  
Flow Loop ◽  
Deposit Thickness ◽  
Depletion Effect ◽  
Study Results

Wax deposition is an extremely common occurrence affecting flow assurance in oil fields. Under the laminar flow condition, the effect of the flow rate on wax deposition is still unclear. In this study, a flow loop test was conducted by considering the depletion effect to investigate the flow effect on wax deposition in single-phase laminar flow. The measured data were compared with the estimated data using models (wax deposition, hydrodynamic, and heat transfer models). The data obtained from the models were matched with the measured data; thus, thereby model parameters were tuned and the wax deposit thickness along the pipeline was estimated with respect to flow rate. The study results indicate that the wax deposit thickness decreases when the flow rate increases at the thickest spot (TS). The volume of wax deposits increases when the flow rate increases. An increase in the flow rate increases the distance between the inlet and the location of the TS.

scholarly journals A model of wax deposition under oil-gas two-phase stratified flow in horizontal pipe

2018 ◽  
Vol 73 ◽  
pp. 80 ◽  
Author(s):  
Jimiao Duan ◽  
Jiang Li ◽  
Huishu Liu ◽  
Kecheng Gu ◽  
Jinfa Guan ◽  
...  
Keyword(s):  
Mass Flux ◽  
Molecular Diffusion ◽  
Diffusion Mechanism ◽  
Interface Temperature ◽  
Solubility Curve ◽  
Wax Deposition ◽  
Flow Loop ◽  
Two Phase ◽  
Horizontal Pipe ◽  
Oil Gas

A model of wax deposition based on molecular diffusion mechanism, for oil-gas two-phase stratified pipe flow is developed. In the model, unidirectional fully developed flow analyses of momentum, heat and mass transfer are presented. And, a cube cage model is used to describe the wax deposit structure considering the effect of oil flow shear on the deposit. Calculation of wax deposit is compared well with a flow loop experiment. In particular, the model could give the wax deposit forming a crescent shape at the cross section of pipe, which is observed in different experiments. Furthermore, the cause of forming a crescent shape is revealed, which is indicated by the non-uniform circumferential distribution of mass flux for wax deposition along the pipe wall wetted by the oil. The mass flux from oil bulk flow to the oil-deposit interface is closely related to three parameters, diffusivity at oil-deposit interface, the temperature gradient at the oil-deposit interface at different time, and the slope of the wax solubility curve at oil-deposit interface temperature.

Effect of operating conditions on wax deposition in a laboratory flow loop characterized with DSC technique

2014 ◽  
Vol 119 (1) ◽  
pp. 471-485 ◽  
Author(s):  
Wenda Wang ◽  
Qiyu Huang ◽  
Changhui Wang ◽  
Si Li ◽  
Wenxing Qu ◽  
...  
Keyword(s):  
Operating Conditions ◽  
Wax Deposition ◽  
Flow Loop
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