The study on temperature field variation and phase transition law after shutdown of buried waxy crude oil pipeline

Cheng, Qinglin; Gan, Yifan; Wang, Peidi; Xu, Ying; Liu, Yang

doi:10.1016/j.csite.2017.10.004

Cited by 19 publications

(14 citation statements)

References 9 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Significant percentage of pipelines worldwide transport waxy crude oils with different amounts of wax contents and, hence, wide range of rheology complexity. In China, for instance, more than 80% of the produced oils are classified as waxy crude [14] with total annual production of over 100 million tons and total annual storage of more than 70 million tons [15]. Worldwide, half of the recoverable oil reserve is classified as heavy crude [16] with the waxy crude contributing about 20% to the total hydrocarbons reserve [17].…”

Section: Transportation Of Waxy Crude Through Pipelinesmentioning

confidence: 99%

Challenges during Operation and Shutdown of Waxy Crude Pipelines

Mohyaldinn¹,

Husin²,

Hasan³

et al. 2019

Processing of Heavy Crude Oils - Challenges and Opportunities

View full text Add to dashboard Cite

Transportation of waxy crude oil faces great challenges due to shear and temperature dependency. At high temperatures, waxy crude exhibits low viscous Newtonian behavior where the resistance to flow due to friction is low, and hence low pumping pressure is required to transport it. At low temperatures, however, the crude exhibits shear thinning non-Newtonian behavior where its apparent viscosity becomes shear-dependent. In such cases, the operated pipeline needs to maintain a high pressure to guarantee a continuous flow. Moreover, due to heat transfer between the internal pipeline and surroundings, oil temperature declines along the pipeline. It follows that the crude viscosity and, hence, frictional resistance increase. If the flow is interrupted for any reason, i.e., emergency or planned shutdown, then the restartability of the pipeline becomes a challenge because of the nonexistence of heating generated from friction. In this chapter, the challenges normally facing transportation of waxy crude oil will be discussed. The chapter will introduce the rheological properties of waxy crude oil and explain and describe how these properties can affect the pressure losses inside the pipeline during its operation and shutdown. The measures that need to be considered when designing a waxy crude pipeline will be discussed.

show abstract

Section: Transportation Of Waxy Crude Through Pipelinesmentioning

confidence: 99%

Challenges during Operation and Shutdown of Waxy Crude Pipelines

Mohyaldinn¹,

Husin²,

Hasan³

et al. 2019

Processing of Heavy Crude Oils - Challenges and Opportunities

View full text Add to dashboard Cite

show abstract

“…With the development of DSC curve to determine the specific heat capacity variation in the phase change process, the application of additional specific heat capacity to describe the phase change problem was an effective way to solve the phase change heat transfer [10,[20][21][22][23]. Zhang [20] regarded the latent heat as an additional specific heat capacity to establish a model, and the solidified cloud maps at different shutdown times were determined.…”

Section: Introductionmentioning

confidence: 99%

“…Liu [21][22] analyzed the temperature distribution of the typical position in a pipeline with an additional latent heat method. Cheng [23] established the temperature drop model for shutdown by apparent heat capacity method, and simulated the distribution of temperature field in pipeline and soil. However, in their models, the non-Newtonian fluid description for crude oil was missing.…”

Section: Introductionmentioning

confidence: 99%

“…Most of the existing studies on the phase change heat transfer of crude oil were to determine the temperature fields or condensate situations at different shutdown times [12][13][14][15][16][17][18][19][20][23][24][25][26][27][28]. In fact, the temperature fields and total freezing time of crude oil in pipeline are two important parameters of oil field operation management, who are closely related to the allowance shutdown time and the pressure required to restart [5,[29][30].…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Sensitivity analysis of crude oil’s physical properties to total freezing time

Liu

et al. 2020

THERM SCI

Self Cite

View full text Add to dashboard Cite

the physical parameters of crude oil are one of the main factors affecting the heat transfer of phase change. A mathematical model for a hot oil overhead pipeline was established, taking latent heat impact, the non-Newtonian properties of crude oil, and nature convection heat transfer into account. Compared with the experimental data, the model and the solution method were correct. And a criterion was made to estimate the crude oil total freezing in a pipeline by tracking the change trajectory of the maximum temperature point. The effects of the crude oil with average properties on the total freezing time in a pipeline were analyzed, and the sensitivity of the different influencing factors was investigated by orthogonal test.

show abstract

“…Computational fluid dynamics (CFD) studies can provide a profound knowledge on the flow and heat-transfer mechanism. 35,40,41 This article describes a mathematical model for crude oil phase change in overhead pipelines that can solve key problems in phase-change heat transfer. According to the phase state of crude oil, the control equations were established between partitions with the latent heat handled by the additional specific heat capacity method, and the analysis of Newtonian and non-Newtonian fluids was performed with the momentum equations.…”

Section: Introductionmentioning

confidence: 99%

Sensitivity analysis of heat dissipation factors in a hot oil pipeline based on orthogonal experiments

Nie

Liu

et al. 2019

Science Progress

Self Cite

View full text Add to dashboard Cite

The study of phase-change heat-transfer characteristics of crude oil has been one of the hot issues in the field of gathering and transportation. The process of phase-change heat transfer of crude oil involves many complicated problems such as natural convection treatment, latent heat treatment, phase-change interface determination and fluid characteristic change. A mathematical model based on the additional capacity heat method is proposed in this article, and the momentum equations of crude oil liquid phase are presented for Newtonian and non-Newtonian fluids. The aim of this study was to investigate the influence of different factors on the heat transfer performance during the shutdown process of an overhead pipe. Experiments were conducted to verify the model and the solution method; the experimental and model results showed good agreement with a maximum relative error of 4.57%. The temperature fields and solidification conditions of crude oil in pipelines under different shutdown conditions were determined, and the sensitivity of the main effect factors was determined through an orthogonal experiment. The results show that the order of influence was oil initial temperature >thickness of insulating layer >air temperature >thickness of wax layer. The results of the study have important guiding significance on the control of shutdown time and the determination of restarting schemes.

show abstract

The study on temperature field variation and phase transition law after shutdown of buried waxy crude oil pipeline

Cited by 19 publications

References 9 publications

Challenges during Operation and Shutdown of Waxy Crude Pipelines

Challenges during Operation and Shutdown of Waxy Crude Pipelines

Sensitivity analysis of crude oil’s physical properties to total freezing time

Sensitivity analysis of heat dissipation factors in a hot oil pipeline based on orthogonal experiments

Contact Info

Product

Resources

About