Polymeric Surfaces for Heavy Oil Pipelines To Inhibit Wax Deposition:  PP, EVA28, and HDPE

The results of investigations of the main causes and the most significant factors of intensification of paraffin deposition in main oil pipelines are presented. A comprehensive analysis of the composition and properties of commercial oils and their sediments was carried out, according to which phase diagrams of equilibrium of oil dispersed systems were obtained using the example of commercial oils from Bashkir fields. Based on the phase diagrams, a curve of wax oil saturation was constructed, the analysis of which confirms that the existing thermobaric conditions during the operation of main oil pipelines do not allow transporting oil without the risk of waxing. It was noted a special influence of the value of the temperature gradient in the near-wall zone and the imbalance of the ratio of high-molecular oil components in commercial batches formed in the process of joint pumping on the intensity of waxing of sections of oil pipelines complicated by deposits, which was confirmed by statistical data on the frequency of pigging. The regularities obtained in this way are proposed to be used as an express method for predicting complications associated with intensive waxing of main oil pipelines. In order to quickly assess the risks of waxing of sections of main oil pipelines, an indicator is introduced that characterizes the ratio of the content of solid paraffins to the total content of resins and asphaltenes of oil, called the criterion of instability of a commercial oil batch.

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Synergistic Effect of Factors Influencing the External Corrosion of Heavy Oil Pipelines in Reed Pond Soil

Journal of Materials Engineering and Performance ◽

10.1007/s11665-021-05678-4 ◽

2021 ◽

Author(s):

YuMing Su ◽

Fei Xie ◽

Dan Wang

Keyword(s):

Synergistic Effect ◽

Heavy Oil ◽

Factors Influencing ◽

Oil Pipelines ◽

External Corrosion

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Role of Shearing Dispersion and Stripping in Wax Deposition in Crude Oil Pipelines

Energies ◽

10.3390/en12224325 ◽

2019 ◽

Vol 12 (22) ◽

pp. 4325

Author(s):

Zhihua Wang ◽

Yunfei Xu ◽

Yi Zhao ◽

Zhimin Li ◽

Yang Liu ◽

...

Keyword(s):

Crude Oil ◽

Flow Rate ◽

Critical Flow ◽

Wax Deposition ◽

Dominant Effect ◽

Critical Flow Rate ◽

Oil Pipelines ◽

Oil Flow ◽

Shearing Mechanism

Wax deposition during crude oil transmission can cause a series of negative effects and lead to problems associated with pipeline safety. A considerable number of previous works have investigated the wax deposition mechanism, inhibition technology, and remediation methods. However, studies on the shearing mechanism of wax deposition have focused largely on the characterization of this phenomena. The role of the shearing mechanism on wax deposition has not been completely clarified. This mechanism can be divided into the shearing dispersion effect caused by radial migration of wax particles and the shearing stripping effect caused by hydrodynamic scouring. From the perspective of energy analysis, a novel wax deposition model was proposed that considered the flow parameters of waxy crude oil in pipelines instead of its rheological parameters. Considering the two effects of shearing dispersion and shearing stripping coexist, with either one of them being the dominant mechanism, a shearing dispersion flux model and a shearing stripping model were established. Furthermore, a quantitative method to distinguish between the roles of shearing dispersion and shearing stripping in wax deposition was developed. The results indicated that the shearing mechanism can contribute an average of approximately 10% and a maximum of nearly 30% to the wax deposition process. With an increase in the oil flow rate, the effect of the shearing mechanism on wax deposition is enhanced, and its contribution was demonstrated to be negative; shear stripping was observed to be the dominant mechanism. A critical flow rate was observed when the dominant effect changes. When the oil flow rate is lower than the critical flow rate, the shearing dispersion effect is the dominant effect; its contribution rate increases with an increase in the oil flow temperature. When the oil flow rate is higher than the critical flow rate, the shearing stripping effect is the dominant effect; its contribution rate increases with an increase in the oil flow temperature. This understanding can be used to design operational parameters of the actual crude oil pipelines and address the potential flow assurance problems. The results of this study are of great significance for understanding the wax deposition theory of crude oil and accelerating the development of petroleum industry pipelines.

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The Use of Biobased Surfactant Obtained by Enzymatic Syntheses for Wax Deposition Inhibition and Drag Reduction in Crude Oil Pipelines

Catalysts ◽

10.3390/catal6050061 ◽

2016 ◽

Vol 6 (5) ◽

pp. 61 ◽

Cited By ~ 9

Author(s):

Zhihua Wang ◽

Xueying Yu ◽

Jiaxu Li ◽

Jigang Wang ◽

Lei Zhang

Keyword(s):

Drag Reduction ◽

Crude Oil ◽

Wax Deposition ◽

Biobased Surfactant ◽

Oil Pipelines

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Dynamic modeling and prediction of wax deposition thickness in crude oil pipelines

Journal of King Saud University - Engineering Sciences ◽

10.1016/j.jksues.2020.05.003 ◽

2020 ◽

Author(s):

Martins Obaseki ◽

Paul T. Elijah

Keyword(s):

Crude Oil ◽

Dynamic Modeling ◽

Wax Deposition ◽

Modeling And Prediction ◽

Oil Pipelines ◽

Deposition Thickness

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Identifying Optimal Pigging Frequency for Oil Pipelines Subject to Non-Uniform Wax Deposition Distribution

Volume 4: Production Pipelines and Flowlines; Project Management; Facilities Integrity Management; Operations and Maintenance; Pipelining in Northern and Offshore Environments; Strain-Based Design; Standards and Regulations ◽

10.1115/ipc2014-33064 ◽

2014 ◽

Cited By ~ 1

Author(s):

Wenda Wang ◽

Qiyu Huang ◽

Si Li ◽

Changhui Wang ◽

Xi Wang

Keyword(s):

Pressure Drop ◽

Model Prediction ◽

Extreme Case ◽

Wax Deposition ◽

Deposition Model ◽

Oil Pipelines ◽

Pump Stations ◽

The Cost

Wax deposition in oil pipelines causes reduced throughput and other associated problems. Periodical pigging program can effectively minimize the cost of wax deposition. This paper shows a typical pigging case study for a field pipeline subject to non-uniform wax deposition distribution by using a developed wax deposition model. The model prediction results prove that the wax is distributed in a short, localized accumulation along the first half pipeline. The resultant pressure drop along the pipeline was examined to reveal the effects of non-uniform wax deposition distribution on the pipeline production. In extreme case, the pressure drop of severe localized section increases by 50%, while this value between pump stations is merely 3%. A maximum wax thickness of 2–4 mm is used as a criterion to determine an optimal pigging frequency. The case study pipeline is recommended to be pigged at a frequency of 10 to 15 days, using by-pass pigs.

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The Model of Wax Precipitation and Experimental Validation

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.463-464.1182 ◽

2012 ◽

Vol 463-464 ◽

pp. 1182-1185 ◽

Cited By ~ 1

Author(s):

Bing Qiang Zhang ◽

Da Shuai Xue ◽

Ji Cheng Yang

Keyword(s):

Rheological Property ◽

Pour Point ◽

Wax Deposition ◽

Wax Precipitation ◽

Oil Pipeline ◽

Waxy Oil ◽

The Past ◽

Oil Pipelines ◽

Experimental Values ◽

Pipeline Safety

A comprehensive review of literature concerning rheological property, and wax deposition during involving the pipeline safety problems is presented. The deposition and gelation of waxy oil pose great flow assurance risks, especially in submarine oil pipeline. Even though there have been a lot of studies and breakthroughs in understanding the wax precipitation and deposition in the past few years, there still continue to be some challenges that have remained unsolved. In order to well understand the rheological property of the crude oil, First of all, the issue need to be solved is study the wax precipitation property of the oil. In this paper, an accurate model of wax precipitation in laboratory condition undergoing a cooling process is established. And then we predicted the wax appearance temperature, pour point and the weight of the wax appearance about the oil sample. Here, the calculated results of model are much close to the experimental values, which shows that the model of wax precipitation developed is correct and reasonable. By accurate prediction the WAT, pour point, we can well understand the rheological property, which will help the operators make an impeccable flow restart plan for the planned or emergency production shut-down of waxy oil pipelines

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Economic pigging cycles for low-throughput pipelines

Advances in Mechanical Engineering ◽

10.1177/1687814018811198 ◽

2018 ◽

Vol 10 (11) ◽

pp. 168781401881119 ◽

Cited By ~ 1

Author(s):

Ying Xie ◽

Diwen Chen ◽

Fangrui Mai

Keyword(s):

Operating Costs ◽

Inlet Temperature ◽

Calculation Methods ◽

Wax Deposition ◽

Waxy Crude Oil ◽

Central Processing ◽

Thermal Constraints ◽

Oil Pipelines ◽

Processing Platform ◽

Power Costs

Wax deposition occurs frequently in waxy crude oil pipelines when the level of flow decreases, and pigging is needed at regular intervals. An economic pigging model is established in accordance with the objective function based on the sum of thermal costs, power costs, and single piping costs. Thus, by compiling a program, the most economical pigging cycle will be determined. Furthermore, the calculation methods for hydraulic and thermal constraints are given. Taking the example of the distance between the central processing platform and the land terminal external piping line of the M-field cluster, the effects of different inlet temperatures, throughput, and remnant wax thicknesses on the economic pigging cycle will be analyzed. The results show that with an increase in the inlet temperature, the total costs of the pipeline operation increase, while the pigging cycle will prolong. As throughput increases, total costs will decrease, while the pigging cycle also extends. When throughput is fixed, a remnant wax thickness of 0.4 mm helps reduce the total operating costs of the pipeline at different inlet temperatures. While throughput varies, a remnant wax thickness from 0.2 to 0.4 mm can reduce total costs at a fixed inlet temperature.

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