Journal of Petroleum Exploration and Production Technology
·
2022
·Vol. 12
·期 7
·2067-2081
·
IF 2.508
Elganidi Ibrahim,Elarbe Basem,Ridzuan Norida,Abdullah Norhayati
Wax 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.
研究领域:
石油工程
·
高分子化学
✓ 已验证
DOI
高影响因子
FUEL
·
2024
·
IF 6.7
Shikun Tong,Yuemeng Ren,Kele Yan,Yanxin Jin,Pengfei Li,Jianbo Zhang,Zhiyuan Wang
The coupling deposition and plugging caused by hydrate formation and wax precipitation during the development of deep water natural gas resources bring new industrial challenges and theoretical difficulty. We designed a single-pass pipeline with two types to investigate deposition behavior and systematically performed the coupling deposition and plugging of hydrate and wax experiments in gas–liquid annular flow . The experimental results illustrate that the single solid phase of hydrate is covered layer sheet deposition, while the coupling solid phase of hydrate and wax is bulk aggregations arch bridge deposition. Meanwhile, the natural eddy zone in reducing pipeline accelerates coupling solid particles deposition. Our finds provided the first knowledge on the double effect that wax crystals inhibit particles adhesion and gel network increases aggregations arch bridge blockage. For the low water content in emulsion system, the gel network provides gathering place for hydrate particles, and the arch bridge structure formed by aggregations accelerates the pipeline blockage. The plugging time is shortened by up to 72.6% with the wax concentration increase from 0 wt% to 3 wt%. For the high water content in emulsion system, the majority of wax crystals adsorbed on the hydrate particles and reduce particles cohesion force, which increase the plugging time. Combined with the microscopic morphology evolution perspective of hydrate particles coupled wax, the coupling deposition of hydrate and wax in gas–liquid annular flow has four stages: gas–liquid flow, coupling solid phase formation, coupling solid phase deposition and sloughing, and coupling solid phase plugging. This study can provide theoretical support and design basis for flow assurance program of deep water gas fields and low temperature natural gas transportation pipelines.
研究领域:
石油工程
·
化学工程
✓ 已验证
DOI
高影响因子
CANADIAN JOURNAL OF CHEMICAL ENGINEERING
·
2025
·
IF 1.9
Qianqian Lv,Chuanshuo Wang,Xiaoxuan Xu,Xiaofang Lv,Wen Xia,Jinru Shang,Aokai Qin,Qianli Ma,Yang Liu,Shidong Zhou,Jimiao Duan
Drag reducers have become a common method for reducing resistance and increasing transportation efficiency in pipeline transportation of waxy crude oil. The prominent heat transfer weakening effect of drag reducers may impact the deposition of waxy oil. This study uses cold finger experiments to clarify wax deposition characteristics and mechanisms in drag-reduced waxy oil. The wax deposition mass and components are examined under different temperatures, stirring rates, drag reducer dosages, and types. The results show that a low dosage of drag reducer at high stirring rates can simultaneously reduce the total wax deposition and the overall wax content in high waxy oil. 5 mg/kg drag reducer can reduce total wax deposition by up to 15.66% and overall wax content by 7.26%. A systematic investigation reveals that adding drag reducers changes the carbon number distribution in the wax deposition layer. This change is similar to the effect of increasing wall temperature. The heat insulation and transfer weakening effects of drag-reducing fluids are likely the main mechanisms inhibiting the increase in wax deposition mass and wax content. The heat insulation effect reduces the temperature gradient near the pipe wall, while the transfer weakening effect decreases radial heat transfer. However, under low stirring rates and high dosages, the deposition mass of the drag-reduced waxy oil system increases, with the adhesive effect of polymer-type drag reducers becoming more pronounced. These findings provide a foundation for optimizing drag reducer usage in waxy crude oil pipelines, potentially leading to significant energy savings and improved operational efficiency.
研究领域:
石油工程
·
化学工程
·
流体力学
·
传热学
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING SCIENCE
·
2024
·
IF 4.1
Xin Lv,Shi Shen,Huiyong Liang,Yanzhen Liu,Haiyuan Yao,Rui Qin,Haihong Chen,Yang Ge,Peng Xiao
Throughout the development of deepwater oil and gas fields, the occurrence of mixed deposition involving wax and hydrate is a prevalent phenomenon. To understand this process, researchers have explored the kinetics and thermodynamic behavior governing the co-deposition of wax and hydrates. It was observed that the Gibbs free energy change of hydrate increases with increasing pressure, while the entropy change experiences a decrease under heightened pressure conditions. The Gibbs free energy change and entropy change of wax crystal precipitation exhibit an increase with rising wax concentration. In a 100 mL sample of simulated crude oil containing 10 vol% moisture and 2.5 wt% wax, the rate of solid phase deposition measures 0.1126 cm 3 /min when the temperature drops from 61 °C to 2 °C. The results exhibit that the dispersion of wax crystals within the oil phase serves to inhibit aggregation phenomenon during hydrate formation and can be effectively used to inhibit hydrate deposition.
研究领域:
石油工程
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
·
2025
·
IF 5.4
Junhuan Zong,Guosheng Ai,Dongyin Yan,Yaming Qi,Long Li,Yuanzhu Mi,Yu Ding,Chunyan Zhang,Xuemin Yan
Wax deposition is a common problem in the transportation of gas condensate and crude oil. Polymers are often used as flow improvers to prevent wax agglomeration. In this work, comb-shaped ternary copolymers poly (imidazole olefin-co-ɑ-olefin-octadecyl maleate) with polar groups and non-polar long chains were synthesized through esterification and free radical polymerization. The influences of the monomer molar ratio of imidazole olefin and the dosage of polymers on the flow properties of gas condensate were studied. The mechanism reveals that the copolymers interacted with wax crystals through adsorption and co-crystallization to modify the van der Waals forces and electrostatic forces between the wax crystal molecules, thereby achieving the purpose of inhibiting wax precipitation. Imidazole olefin, ɑ-olefin and octadecyl maleate with a molar ratio of 1:10:10 exhibits optimal flow performance on waxy gas condensate. The pour point and wax appearance temperature of the condensate oil containing 4% on-site wax after being treated with NCMO-2 was reduced by 22 ℃ and 11 ℃, respectively. This work provides a reference for the synthesis of flow improvers for waxy condensate oil.
研究领域:
石油工程
·
高分子化学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
Energies
·
2021
·Vol. 14
·期 24
·8243
·
IF 3.004
Xinyuan Li,Shu Lu,Meifei Niu,Ruzhen Cheng,Yanjun Gong,Jun Xu
A high content of asphaltene and wax in crude oil leads to difficulties in the recovery and transportation of crude oil due to the precipitation of asphaltenes and the deposition of waxes. Comb-like polymers were found to be capable of inhibiting the aggregation of asphaltenes and crystallization of waxes. In this work, comb-like bipolymers of α-olefins/ultra-long chain (C18, C22 and C28) alkyl acrylate were synthesized and characterized by FT-IR and1H NMR spectra. The results show that, for a model oil containing asphaltene, the initial precipitation point (IPP) of asphaltene was prolonged by UV, and the asphaltene particle size was reduced after adding the biopolymers, as revealed by dynamitic light scattering (DLS). The bipolymer containing the longer alkyl chain had a better asphaltene inhibition effect. However, DSC and rheological results show that the wax appearance temperature (WAT) of the typical high asphaltene and high wax content of crude oil was obviously reduced by adding bipolymers with shorter alkyl chains. The bipolymer (TDA2024-22) with a mediate alkyl chain (C22) reduced the viscosity and thixotropy of the crude oil by a much larger margin than others. Compared with the previously synthesized bipolymer with phenyl pendant (PDV-A-18), TDA2024-22 exhibited a better performance. Therefore, bipolymers with appropriate alkyl side chains can act as not only the asphaltene inhibitors but also wax inhibitors for high asphaltene and wax content of crude oil, which has great potential applications in the oil fields.
研究领域:
石油工程
·
材料科学
✓ 已验证
DOI
高影响因子
Petroleum Science
·
2023
·
IF 5.6
Bo Yao,Hao-Ran Zhu,Bao-Dong Yan,Chuan-Xian Li,Fei Yang,Guang-Yu Sun,Hong-Bo Zeng
This paper investigated the effects of pre-heating treatment temperatures ( T pre ) on the flowability and wax deposition characteristics of a typical waxy crude oil after adding wax inhibitors. It is found that there is little difference in wax precipitation exothermic characteristics of crude oils at different T pre , as well as the wax crystal solubility coefficient in the temperature range of 25–30 °C. For the undoped crude oil, the flowability after wax precipitation gets much improved and the wax deposition is alleviated as T pre increasing. At T pre = 50 °C, the viscosity and wax deposition rate of crude oil adding wax inhibitors are higher than those of the undoped crude oil. When the T pre increases to 60, 70, and 80 °C, the flowability of the doped crude oil are largely improved and the wax deposition is suppressed with the T pre increase, but the wax content of wax deposit increases gradually. It is speculated that, on the one hand, the T pre increase helps the dispersion of asphaltenes into smaller sizes, which facilitates the co-crystallization with paraffin waxes and generates more aggregated wax crystal flocs. This weakens the low-temperature gel structure and increases the solid concentration required for the crosslink to form the wax deposit. On the other hand, the decrease in viscosity increases the diffusion rate of wax molecules and accelerates the aging of wax deposits. The experimental results have important guiding significance for the pipeline transportation of doped crude oils.
研究领域:
石油工程
·
化学工程
✓ 已验证
DOI
高影响因子
CHEMICAL ENGINEERING SCIENCE
·
2024
·
IF 4.1
Yang Liu,Yan Zhang,Xiaofang Lv,Yisong Yu,Shuang Ren,Qianli Ma,Chuanshuo Wang,Shidong Zhou,Bingcai Sun
As oil and gas extraction increasingly ventures into deep-sea environments, the issues surrounding the flow safety of hydrate and wax deposits have become more critical. There is an urgent need to develop environmentally friendly and adaptable hydrate anti-agglomerants, and to expand the database and knowledge base for risk management strategies to ensure optimal production safety. This study formulated combined anti-agglomerants with varying HLB values using Span 80 and Tween 80 in different ratios. Rheological experiments were conducted to investigate their synergistic anti-agglomeration performance in water-in-oil emulsions and their adaptability in environments with wax, varying water contents, and different continuous phase compositions. The results indicate that, in comparison to a single anti-agglomerant, the combined anti-agglomerants not only increases the critical time for hydrate formation but also reduces peak viscosity and stable viscosity by 23–90 % and 25–85 %, respectively. Additionally, an index for assessing the flow risk of hydrate slurries under specific conditions was proposed, which demonstrates that the combined anti-agglomerant with an HLB value of 8.6 exhibits exceptional performance across various conditions. This finding is significant for refining risk management strategies for hydrates in deep-sea oil and gas transportation processes.
研究领域:
石油工程
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2025
·
IF 13.2
Zhen Long,Aolin Liang,Lexin Zhang,Xuebing Zhou,Jiaqi Wang,Qian Zhang,Deqing Liang
Hydrate blockage and wax deposition have become two major hazards for deep-sea oil gas flow assurance industry. The existing prevention methods are mainly oriented to single solid phase blockage, yet how they affect multi-solid phases is rarely known. Moreover, the interaction of hydrate and wax remains unclear. Recently, adding pour point depressants (PPDs) has been proposed to be a novel technique to efficiently improve the rheology of waxy oil and prevent hydrate formation. In this paper, a series of mono-dispersed polymethylsiloxane (PMSQ) microspheres with different average sizes (0.5, 1.0 and 2.0 μm) were successfully synthesized and studied their effects on the wax deposition of waxy oil and the formation kinetics and aggregation behavior of CH 4 hydrate in the waxy oil–water system. The wax appearance temperature (WAT) test showed that PMSQ with a smaller size was more beneficial to reduce the WAT of waxy oil. Though poor in delaying hydrate nucleation, single PMSQ inhibited the hydrate growth and aggregation well, opposite to the role of wax. A synergistic/antagonistic effect of wax with PMSQ on preventing hydrate nucleation, growth and agglomeration was produced, depending on the wax content, size and dosage of PMSQ. Microstructure measurements indicated that wax and PMSQ were unable to alter the crystal structure of sI CH 4 hydrate, but significantly influenced the distribution of CH 4 in the hydrate cages, particularly large cage. The results give a deeper understanding of the inhibition mechanism and the synergistic potential of various additives, as well as providing a theoretical support for the PPDs used in the pipelines of natural gas production and transportation.
研究领域:
石油工程
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
ENERGY & FUELS
·
2020
·
IF 3.421
Haoran Zhu,Chuanxian Li,Zongming Xiu,Zhiqiang Zhao,Kai Mu,Hui Dai,Feng Wang,Fei Yang,Bo Yao
In this paper, a novel ethylene-vinyl acetate copolymer (EVA)/amino-functionalized polymethylsilsesquioxane (PAMSQ) composite wax inhibitor (WI) was prepared through melt blending, and the rheological and wax depositing properties of the doped crude oil were studied. The EVA/PAMSQ composite can strongly crystallize with wax molecules and trigger the formation of compact wax flocs, which greatly improve the rheological properties of crude: compared to the pure EVA at the same dosage, the composite can further decrease the gel point and apparent viscosity (25 °C) by 14.6 °C and 92.0%, respectively. The wax deposition can also be inhibited by adding the composite: adding EVA inhibits the mass of the wax deposit at 24 h by 62.3%, and this number is suppressed by 77.9% after adding the EVA/PAMSQ composite, but the wax molecule diffusion is accelerated and the wax content in the wax deposit rises because of the improved crude oil rheological characteristics. Here, we develop the gel structure theory to consider the wax deposition process affected by the WI. Adding the WI contributes little to the wax precipitation temperature but decreases the gel structural strength of the oil a lot, and thus, the oil near the pipe wall can only form the wax deposit with a higher wax content to resist the pipe wall shearing. Therefore, the crude oil added EVA/PAMSQ composite possesses not only the lowest wax deposit rate and the highest aging rate but also the highest wax content in the wax deposit.
研究领域:
材料科学
·
石油工程
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF INDUSTRIAL AND ENGINEERING CHEMISTRY
·
2022
·
IF 6.76
Jie Qi,Xiaojiang Li,Xin Lv,Yang Ge,Jinyu Wang,Hongsheng Lu
Wax precipitation leads to destructive harms in the exploitation and transportation of petroleum. Solvent treatments can remove paraffin wax easily but the separation of solvent relying on distillation is admitted inefficient. Aiming at enhancing the separation and recovery performance of paraffin wax, CO 2 -responsive emulsion (SHS/W emulsion) based on switchable hydrophilicity solvents (SHS) is adopted. Since the paraffin wax is dissolved, emulsified, and dispersed by SHS/W emulsion, SHS/W emulsion exhibits better removal performance than SHS. The paraffin wax is recovered effectively upon introducing CO 2 , which attributes to the transformation of SHS from hydrophobic to hydrophilic state. Compared with the SHS system, the recovery of paraffin wax is improved obviously by introducing surfactant Span80. Owing to the deprotonation of SHS by bubbling N 2 and heating, 77.6% SHS is recycled after recovering paraffin wax. Here, the recycled SHS can be used to realize the removal of paraffin wax again. Thus, it is a promising and alternative strategy for realizing the sustainable and rapid removal of paraffin wax in the petroleum industry.
研究领域:
化学工程
·
石油工程
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
ENERGY & FUELS
·
2024
·
IF 5.2
Lexin Zhang,Zhen Long,Yong He,Jinhang Wang,Xuebing Zhou,Lingli Shi,Deqing Liang
Wax deposition and hydrate formation are two unwelcome problems that can threaten the safety of pipeline transportation in the oil and gas industry. The existing prevention methods mainly aim at the flow blockage resulting from single solid phase, but rarely take into account multi-solid-phase systems, such as hydrate-wax, hydrate-sand, etc. Recently, it has been proposed that adding pour point depressants (PPDs) can not only improve the rheological property of waxy oil but also have potential to inhibit hydrate formation. In this study, a series of PPD polymethylsilsesquioxane (PMSQ) microspheres were synthesized by a two-step sol–gel method. First, the effect of PMSQ microspheres on wax deposition in waxy mineral oil was tested by differential scanning calorimetry (DSC). Then, the influence of PMSQ microspheres on the cyclopentane (CP) hydrate formation in waxy oil–water systems at the atmospheric pressure and temperature of −3 °C was investigated by using a self-assembly high-pressure reactor. The experimental results showed that the addition of PMSQ microspheres could reduce the wax appearance temperature (WAT) of waxy oil and prolong the nucleation time of the CP hydrate. Powder X-ray diffraction and laser confocal micro-Raman data indicated that the presence of PMSQ did not affect the sII crystal structure of the CP hydrates. A possible inhibition mechanism of PMSQ microspheres by the steric hindrance effect was proposed.
研究领域:
化学工程
·
材料科学
·
石油工程
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）