Wax inhibitor performance comparison for waxy crude oil from Fang oilfield

In petroleum chemistry, waxy oil from paraffins can cause operating problems for oil production. The chemical method is used to remove by using chemicals or additives to prevent the wax problem. In this study, the performance of wax inhibitor are evaluated by the measurement of pour-point reduction and wax deposition of crude oil from Mae Soon area, Fang oilfield. Wax deposition is determined by cold finger technique. Wax inhibitors, hexane, Poly(maleic anhydride-alt-1-octadecene) (PMAO) and monoethanolamine (MEA) are mixed in oil sample at various concentrations. From the experiment, it is presented that hexane is used to reduce pour-point temperature up to 19.55 % and to reduce wax deposit up to 92.56 %. Moreover, MEA and PMAO have less effect on pour-point reduction. However, they have high efficiency to prevent wax deposition. PMAO provide the better wax deposition performance than MEA. The amount of wax deposit is lower at the same conditions. The percentage of wax deposit is from 39.19 % to 83.02 % for MEA and from 58.54 % to 88.51 % for PMAO. Furthermore, from the results, the preferred concentration of hexane can be at 10 % and PMAO can be 7500 ppm at low temperature or 5000 ppm for higher temperature. The results of this research can be applied to the practical way for wax deposition prevention operation in Mae Soon area in Fang oilfield to reduce the wax problem in the future.

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Synthesis, characterisation and pre-evaluation of a novel terpolymer as pour point depressants to improve the Malaysian crude oil flowability

Journal of Petroleum Exploration and Production Technology ◽

10.1007/s13202-021-01445-2 ◽

2022 ◽

Author(s):

Ibrahim Elganidi ◽

Basem Elarbe ◽

Norida Ridzuan ◽

Norhayati Abdullah

Keyword(s):

Reaction Time ◽

Crude Oil ◽

Pour Point ◽

Maximum Efficiency ◽

Initiator Concentration ◽

Wax Deposition ◽

Oil Viscosity ◽

Cold Finger ◽

Waxy Crude Oil ◽

Pour Point Depressants

AbstractWax deposition is considered one of the most serious operational issues in the crude oil pipelines. This issue occurs when the crude oil temperature decreases below the temperature of wax appearance and paraffin wax starts to precipitate on the pipelines’ inner walls. As a result, the crude oil flow is impeded because of the precipitated wax. The use of polymeric pour point depressants has obtained significant interest among researchers as an approach of wax control for enhancing the flowability of the waxy crude oil. PPD of poly(behenyl acrylate -co-stearyl methacrylate-co- maleic anhydride) (BA-co-SMA-co-MA) was facilely synthesised by the use of free radical polymerisation. The variation of the PPD structure was studied by choosing several essential parameters like monomers ratio, reaction time, initiator concentration, and reaction temperature. Furthermore, viscosity measurement, pour point, and cold finger apparatus have been employed to evaluate the efficiency of the synthesised Polymer. The chemical structure of poly(BA-co-SMA-co-MA) has been identified through the use of Fourier transform infrared as well as nuclear magnetic resonance. The experimental findings demonstrated that the ideal conditions for obtaining the highest yield were 1.5% initiator concentration, reaction time and temperature of 8 h and 100 °C, respectively, and monomer ratio of 1:1:1 (BA:SMA:MA). Under these ideal conditions, the prepared terpolymer reduced the crude oil viscosity at 30 °C and 1500 ppm from 7.2 to 3.2 mPa.s. The cold finger experiment demonstrated that after poly(BA-co-SMA-co-MA) was used as a wax inhibitor, the maximum efficiency of paraffin inhibition of 45.6% was achieved at 200 rpm and 5 °C. Besides, the best performance in depressing the pour point by ΔPP 14 ℃ observed at the concentration of 1500 ppm, which can change the growth characteristics of wax crystals and delay the aggregation of asphaltene and resin, thus effectively improving the flowability of crude oil.

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Review on the gelation of wax and pour point depressant in crude oil multiphase system

International Journal of Modern Physics B ◽

10.1142/s021797922130005x ◽

2021 ◽

Vol 35 (12) ◽

pp. 2130005

Author(s):

Hongmei Xu ◽

Yanpu Wang ◽

Kun Wang

Keyword(s):

Crude Oil ◽

Pour Point ◽

Molecular Design ◽

Research Progress ◽

Multiphase System ◽

Wax Deposition ◽

Pour Point Depressant ◽

Waxy Crude Oil ◽

Waxy Crude ◽

Point Depressant

The gelation of waxy crude oil multiphase system can result in the formation of network cementitious structure, which seriously impacts the safe and economic production of crude oil. This paper reviews current experimental, theoretical and numerical results on the gelation of wax in crude oil. For the experimental side, the most important problems are in situ measurement and measurement accuracy. On the theoretical side, the present methods own defects of low accuracy and limited application scope. Numerically, the models are of oversimplification, which are hardly applied to the real production. Besides, as a promising solution, the research progress of crude oil pour point depressant is also reviewed. The molecular design is a powerful approach to develop the optimized pour point depressant. The goals of this paper are to bridge the microscale atomic interactions and the macroscale physicochemical properties of waxy crude oil and pour point depressant, so as to lay a solid theoretical basis for preventing and controlling wax deposition in crude oil. These are beneficial to the future efficient, clean and safe energy production system.

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Pour Point Reduction of Waxy Crude Oil by Pyrolysis in Supercritical Methanol

Industrial & Engineering Chemistry Research ◽

10.1021/acs.iecr.8b02409 ◽

2018 ◽

Vol 57 (34) ◽

pp. 11833-11841

Author(s):

Yong Chen ◽

Li-Tao Wang ◽

Hao Qu ◽

Jing-Yi Yang ◽

Pei-Qing Yuan ◽

...

Keyword(s):

Crude Oil ◽

Pour Point ◽

Supercritical Methanol ◽

Waxy Crude Oil ◽

Waxy Crude ◽

Point Reduction

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Study of Wax Deposition Pattern of High Wax-Bearing Crude Oil Based on Cold Finger Experiment

Processes ◽

10.3390/pr10010103 ◽

2022 ◽

Vol 10 (1) ◽

pp. 103

Author(s):

Lixin Wei ◽

Da Li ◽

Chao Liu ◽

Zhaojun He ◽

Yang Ge

Keyword(s):

Crude Oil ◽

Deposition Rate ◽

Rotation Rate ◽

Deposition Time ◽

Wax Deposition ◽

Deposition Pattern ◽

Cold Finger ◽

Waxy Crude Oil ◽

Waxy Crude ◽

Wall Deposition

In order to solve the problem of wax deposition in waxy crude oil from the Daqing oilfield, cold fingers were used in the experimentation. Compared with other methods, the cold finger method is simple, easy to operate, and takes little space. Measurements of wax deposition with temperature, temperature differences between the crude oil and the wall, deposition time, and cold finger rotation rate were made. The results showed that the deposition rate is up to 0.35 g/h at 8–24 h. The maximum deposition rate at 90 rotations/min was 0.26 g/h, which is 3% higher than the minimum deposition rate.

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Effect of Pour Point Depressants on the Impedance Spectroscopy of Waxy Crude Oil

Energy & Fuels ◽

10.1021/acs.energyfuels.0c03378 ◽

2020 ◽

Vol 35 (1) ◽

pp. 433-443

Author(s):

Hongying Li ◽

Chaohui Chen ◽

Qian Huang ◽

Yifei Ding ◽

Yu Zhuang ◽

...

Keyword(s):

Impedance Spectroscopy ◽

Crude Oil ◽

Pour Point ◽

Waxy Crude Oil ◽

Waxy Crude ◽

Pour Point Depressants

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Effects of 4-vinylbenzyl trioctylphosphonium- bentonite containing poly(octadecylacrylate-co-1-vinyldodecanoate) pour point depressants on the cold flow characteristics of waxy crude oil

Fuel ◽

10.1016/j.fuel.2020.118817 ◽

2020 ◽

Vol 282 ◽

pp. 118817

Author(s):

M.A. Betiha ◽

Tahany Mahmoud ◽

A.M. Al-Sabagh

Keyword(s):

Crude Oil ◽

Pour Point ◽

Flow Characteristics ◽

Waxy Crude Oil ◽

Waxy Crude ◽

Cold Flow ◽

Pour Point Depressants

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Application of Synthesized Novel Biodegradable Pour-Point Depressant from Natural Source on Flow Assurance of Indian Waxy Crude Oil and Comparative Studies with Commercial Pour-Point Depressant

SPE Journal ◽

10.2118/208578-pa ◽

2021 ◽

pp. 1-13

Author(s):

Biswadeep Pal ◽

Tarun Kumar Naiya

Keyword(s):

Interfacial Tension ◽

Crude Oil ◽

Pour Point ◽

Microscopic Analysis ◽

Proton Nuclear Magnetic Resonance ◽

Flow Assurance ◽

Pour Point Depressant ◽

Waxy Crude Oil ◽

Waxy Crude ◽

Point Depressant

Summary Pour-point depressants (PPDs) were synthesized from natural sources and used in waxy crude oil transportation to reduce the pour point and improve flow. A biodegradable PPD (BPPD) was synthesized and tested to mitigate crude oil flow assurance problems in the present work. The transesterification process was used to synthesize coconut oil ethyl ester (COEE, termed as BPPD). Fourier transform electron spectroscopy (FTIR), proton nuclear magnetic resonance (H-NMR), and microscopic analysis were performed for better understanding of mechanisms for both BPPD and a commercially available PPD named PPD-A. The pour point of crude oil was reduced by 12 and 9°C after the addition of 800 ppm BPPD and PPD-A, respectively. The microscopic analysis confirms that the crystals of wax converted to very fine and dispersed particles during mixing of additives, which in turn increase flowability. BPPD performs better to reduce interfacial tension than PPD-A. The maximum reduction of 19% in interfacial tension was observed after the addition of 800 ppm BPPD. BPPD alters the wettability of the pipeline surface from intermediate wet to water-wet within 60 seconds, which results in reduced slip velocity and consequently lessens the deposition of wax. As a result, crude oils will not stick to the wall of the pipe surface and will experience less resistance to flow through pipelines. FTIR analysis indicated that long-chain alkane and aromatic groups are responsible for a higher pour point, and their concentration level was reduced after the addition of BPPD. The viscosity of crude oil was reduced by almost 94% after the addition of 800 ppm BPPD with crude oil, which in turn minimizes pumping costs for crude oil. As a result, the total project cost was reduced substantially. Biodegradability tests confirm that the BPPD is biodegradable and nontoxic. Due to its biodegradability and nontoxic nature, BPPD has a promising capacity to be used in the petroleum industry for easier pipeline transportation of waxy crude.

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