scholarly journals Study on Demulsification-Flocculation Mechanism of Oil-Water Emulsion in Produced Water from Alkali/Surfactant/Polymer Flooding

Polymers ◽  
2019 ◽  
Vol 11 (3) ◽  
pp. 395 ◽  
Author(s):  
Bin Huang ◽  
Xiaohui Li ◽  
Wei Zhang ◽  
Cheng Fu ◽  
Ying Wang ◽  
...  

The issue of pipeline scaling and oil-water separation caused by treating produced water in Alkali/Surfactant/Polymer (ASP) flooding greatly limits the wide use of ASP flooding technology. Therefore, this study of the demulsification-flocculation mechanism of oil-water emulsion in ASP flooding produced water is of great importance for ASP produced water treatment and its application. In this paper, the demulsification-flocculation mechanism of produced water is studied by simulating the changes in oil-water interfacial tension, Zeta potential and the size of oil droplets of produced water with an added demulsifier or flocculent by laboratory experiments. The results show that the demulsifier molecules can be adsorbed onto the oil droplets and replace the surfactant absorbed on the surface of oil droplets, reducing interfacial tension and weakening interfacial film strength, resulting in decreased stability of the oil droplets. The demulsifier can also neutralize the negative charge on the surface of oil droplets and reduce the electrostatic repulsion between them which will be beneficial for the accumulation of oil droplets. The flocculent after demulsification of oil droplets by charge neutralization, adsorption bridging, and sweeping all functions together. Thus, the oil droplets form aggregates and the synthetic action by the demulsifier and the flocculent causes the oil drop film to break up and oil droplet coalescence occurs to separate oil water.

2020 ◽  
Vol 4 (4) ◽  
pp. 1-7
Author(s):  
Zhang D

The basic properties of alkali‒surfactant‒polymer (ASP) flooding produced water and effect of oil displacing agent on the stability of flooding produced water were obtained, through measuring and analysing water quality, oil content-settling time relationship and oil displacing agent-oil droplet size relationship of Zhong-106, Zhong-312, Zhong-417, Nan 4-8 and Bei 2-7 flooding produced water from Daqing Oilfield. The addition of ternary oil displacement agent to ASP flooding produced water greatly increases the difficulty of oil-water separation, and higher the concentration, worse the separation effect after standing. The effects of alkali, surfactant, and polymer on oil-water stability in simulated ASP flooding produced water were studied respectively. The ASP flooding produced water after 48 hours of settling formed a trace amount of nano-oil droplets, also accompanied by the accumulation and separation of a part of the oil droplets.


RSC Advances ◽  
2020 ◽  
Vol 10 (26) ◽  
pp. 15124-15131 ◽  
Author(s):  
Hao Sun ◽  
Xin He ◽  
Qian Tang ◽  
Xiaobing Li

A recyclable functional microsphere was developed which significantly enhances oil–water separation and decreases chemical demulsifier consumption.


Processes ◽  
2020 ◽  
Vol 8 (3) ◽  
pp. 315 ◽  
Author(s):  
Bin Huang ◽  
Chen Wang ◽  
Weisen Zhang ◽  
Cheng Fu ◽  
Haibo Liu ◽  
...  

With the wide application of ASP (alkali/surfactant/polymer) flooding oil recovery technology, the produced water from ASP flooding has increased greatly. The clay particles carried by crude oil in the process of flow have a synergetic effect with oil displacement agents in the produced water, which increases the treatment difficulty of produced water. The stability of produced water is decided by the stability of oil droplets in the ASP-flooding-produced water system. The oil content, Zeta potential, interfacial tension and oil droplet size are important parameters to characterize the stability of produced water. In this paper, the changes of the oil content, Zeta potential, interfacial tension and oil droplet size of ASP flooding oily wastewater under the synergetic effect of different concentrations of quartz sand particles and oil displacement agents were studied by laboratory experiments. The experimental results show that the negatively charged quartz sand particles can absorb active substances in crude oil and surfactant molecules in the water phase and migrate to the oil–water interface, which increases the repulsion between quartz sand particles, decreasing the oil–water interfacial tension. Thus, the stability of oil droplets is enhanced, and the aggregation difficulty between oil droplets and quartz sand particles is increased. With the continually increasing quartz sand concentration, quartz sand particles combine with surfactant molecules adsorbed on the oil–water interface to form an aggregate. Meanwhile, the polymer molecules crimp from the stretching state, and the number of them surrounding the surface of the flocculation structure is close to saturation, which makes the oil droplets and quartz sand particles prone to aggregation, and the carried active substances desorb from the interface, resulting in the instability of the produced water system. The research on the synergetic effect between quartz sand particles and oil displacement agents is of great significance for deepening the treatment of ASP-produced water.


2021 ◽  
Author(s):  
Abdelhak Ladmia ◽  
Dr. Younes bin Darak Al Blooshi ◽  
Abdullah Alobedli ◽  
Dragoljub Zivanov ◽  
Myrat Kuliyev ◽  
...  

Abstract The expected profiles of the water produced from the mature ADNOC fields in the coming years imply an important increase and the OPEX of the produced and injected water will increase considerably. This requires in-situ water separation and reinjection. The objective of in-situ fluid separation is to reduce the cost of handling produced water and to extend the well natural flow performance resulting in increased and accelerated production. The current practice of handling produced water is inexpensive in the short term, but it can affect the operating cost and the recovery in the long term as the expected water cut for the next 10-15 years is forecasted to incease significantly. A new water management tool called downhole separation technology was developed. It separates oil and & gas from associated water inside the wellbore to be reinjected back into the disposal wells. The Downhole Oil Water Separation (DHOWS) Technology is one of the key development strategies that can reduce considerable amounts of produced water, improve hydrocarbon recovery, and minimize field development cost by eliminating surface water treatment and handling costs. The main benefits of DHOWS include acceleration of oil offtake, reduction of production cost, lessening produced water volumes, and improved utilization of surface facilities. In effect, DHOWS technologies require specific design criteria to meet the objectives of the well. Therefore, multi--discipline input data are needed to install an effective DHOWS with a robust design that economically outperforms and boosts oil and/or gas productions. This paper describes the fundamental criteria and workflow for selecting the most suitable DHOWS design for new and sidetracked wells to deliver ADNOC production mandates in a cost-effective manner while meeting completion requirements and adhering to reservoir management guidelines.


2020 ◽  
Vol 44 (48) ◽  
pp. 20999-21006
Author(s):  
Junda Wu ◽  
Atian Xie ◽  
Jin Yang ◽  
Jiangdong Dai ◽  
Chunxiang Li ◽  
...  

A facile modification of a PVDF membrane using CaCO3 inorganic particles via a layer-by-layer self-assembly process for efficient oil/water separation.


2014 ◽  
Vol 556-562 ◽  
pp. 867-871
Author(s):  
Qiu Shi Zhao

It is significative to study sewage treatment process in low permeable oil fields. It could enhance the oil recovery. The water quality characteristics and oil/water separation characteristics were researched during different period process by GC-MS. It shows that there are about 108 kinds of organic matters, including 45 kinds of aliphatic hydrocarbon, 7 kinds of aine, 5 kinds of sulfocompound and 9 kinds of hexacyclic compounds, such as Benzene, phenol, naphthalene and anthracene. The percent of oil droplets which size was less than 10μm is 57.3%, compared to 91.6% which size was more than 50μm. It is difficult to separate the water and oil. The remaining oil was emulsified oil. The process was hard to decrease COD, and some pollutants were existed in water, such as Arsenic, Selenium, Mercury ,Cadmium and Cr6+. It is further proposed to optimize and develop this process to removal oil and suspended solids.


2014 ◽  
Vol 945-949 ◽  
pp. 3475-3478
Author(s):  
Bao Jun Liu ◽  
Jing Cheng Shi ◽  
Li Ping Guo ◽  
Yin Peng Li

Adopts the method of adding demulsifiers into the oily wastewater to increase the droplets size to further improve the efficiency of oil-water separation, and puts forward the corresponding optimized indicators and methods of demulsifiers. The optimized selection of the demulsifiers and its additive dosage was carried out by indoor experiments based on the optimized indicators. Using artificial produced water to test the treatment effect of the optimized demulsifier at different action time. The experiments show that demulsifier S1 with additive dosage of 20mg/l can accordance with the requirements of the processing very well, and as the increase of action time, the average size of droplets increase and the amount of the droplets which under 1μm decrease.


2018 ◽  
Vol 5 (5) ◽  
pp. 171979 ◽  
Author(s):  
S. S. Shen ◽  
K. P. Liu ◽  
J. J. Yang ◽  
Y. Li ◽  
R. B. Bai ◽  
...  

A hollow fibre membrane was fabricated by blending polyvinylidene fluoride (PVDF) with a triblock copolymer additive polymer that has both hydrophilic and oleophobic surface properties. The novel membrane was characterized and examined for oil/water separation under various system conditions, including different cross-flow rate, feed temperature, trans-membrane pressure, and its rejection and cleaning efficiency, etc. By applying the membrane into the filtration of synthesized oil/water emulsion, the membrane constantly achieved an oil rejection rate of above 99%, with a relatively constant permeate flux varied in the range of 68.9–59.0 l m −2  h −1 . More importantly, the fouling of the used membrane can be easily removed by simple water flushing. The membrane also demonstrated a wide adaptability for different types of real oily wastewater, even at very high feed oil concentration (approx. 115 000 mg l −1 in terms of chemical oxygen demand (COM)). Hence, the novel triblock copolymer additive-modified PVDF membrane can have a great prospect in the continuing effort to expand the engineering application of polymeric membranes for oily wastewater treatment.


Materials ◽  
2021 ◽  
Vol 14 (20) ◽  
pp. 5916
Author(s):  
Xiaotian Yu ◽  
Xian Zhang ◽  
Yajie Xing ◽  
Hongjing Zhang ◽  
Wuwei Jiang ◽  
...  

A new type of Janus cellulose acetate (CA) fiber membrane was used to separate oil–water emulsions, which was prepared with plasma gas phase grafting by polymerizing octamethylcyclotetrasiloxane (D4) onto a CA fiber membrane prepared by centrifugal spinning. The Janus–CA fiber membrane was described in terms of chemical structure using Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS) analysis, energy dispersive X-ray spectroscopy (EDX) analysis and morphology by field emission scanning electron microscopy (FESEM). In this contribution, we examine the influence of spinning solution concentration, spinning speed and nozzle aperture on the centrifugal spinning process and the fiber morphology. Superhydrophobic/hydrophilic Janus–CA fiber membrane was used to separate water and 1,2-dibromoethane mixture and Toluene-in-water emulsion. Unidirectional water transfer Janus–CA fiber membrane was used to separate n-hexane and water mixture. The separation for the first-time interception rate was about 98.81%, 98.76% and 98.73%, respectively. Experimental results revealed that the Janus cellulose acetate (CA) fiber membrane gave a permeate flux of about 43.32, 331.72 and 275.27 L/(m2·h), respectively. The novel Janus–CA fiber membrane can potentially be used for sustainable W/O emulsion separation. We believe that this is a facile strategy for construction of filtration materials for practical oil–water separation.


2014 ◽  
Vol 2 (30) ◽  
pp. 11830-11838 ◽  
Author(s):  
Xiaoyu Li ◽  
Dan Hu ◽  
Kun Huang ◽  
Chuanfang Yang

Stainless steel felt modified with hierarchically structured coatings and hydrophobicity can achieve a removal efficiency of greater than 99% for oil-in-water emulsion separation.


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