scholarly journals Interception Characteristics and Pollution Mechanism of the Filter Medium in Polymer-Flooding Produced Water Filtration Process

Processes ◽  
2019 ◽  
Vol 7 (12) ◽  
pp. 927
Author(s):  
Xingwang Wang ◽  
Xiaoxuan Xu ◽  
Wei Dang ◽  
Zhiwei Tang ◽  
Changchao Hu ◽  
...  

Polymer flooding enhances oil recovery, but during the application of this technology, it also creates a large amount of polymer-contained produced water that poses a threat to the environment. The current processing is mainly focused on being able to meet the re-injection requirements. However, many processes face the challenges of purifying effect, facilities pollution, and economical justification in the field practice. In the present work, to fully understand the structure and principle of the oil field filter tank, and based on geometric similarity and similar flow, a set of self-designed filtration simulation devices is used to study the treatment of polymer-contained produced water in order to facilitate the satisfaction of the water injection requirements for medium- and low-permeability reservoirs. The results show that, due to the existence of polymers in oil field produced water, a stable colloidal system is formed on the surface of the filter medium, which reduces the adsorption of oil droplets and suspended solids by the filter medium. The existence of the polymers also increases the viscosity of water, promotes the emulsification of oil pollution, and increases the difficulty of filtration and separation. As filtration progresses, the adsorption of the polymers by the filter medium bed reaches saturation, and the polymers and oil pollution contents in the filtered water increase gradually. The concentration and particle size of the suspended solids eventually exceed the permissible standards for filtered water quality; this is mainly due to the unreasonable size of the particle in relation to the filter medium gradation and the competitive adsorption between the polymers and the suspended solids on the surface of the filter medium. The oil concentration of the filtered water also exceeds the allowable standards and results from the polymers replace the oil droplets in the pores and on the surfaces of the filter medium. Moreover, the suspended particles of the biomass, composed of dead bacteria, hyphae, and spores, have strong attachment and carrying ability with respect to oil droplets, which cause the suspended solids in the filtered water to exceed the permissible standards and oil droplets to be retained in the filtered effluent at the same time.

Energies ◽  
2020 ◽  
Vol 13 (20) ◽  
pp. 5288
Author(s):  
Xianguo Zhang ◽  
Chengyan Lin ◽  
Yuqi Wu ◽  
Tao Zhang ◽  
Hongwei Wang ◽  
...  

During water and polymer flooding for enhanced oil recovery, pore structures may vary because of the fluid–rock interactions, which can lead to variations in petrophysical properties and affect oil field production. To investigate the effects of fluid flooding on pore structures, six samples were subjected to brine water, dual-system, and alkaline–surfactant–polymer (ASP) polymer displacement experiments. Before and after experiments, samples were scanned by X-ray CT. Thin sections, X-ray diffraction, and high pressure mercury injection tests were also carried out to characterize mineralogy and fractal dimension of pore systems before experiments. Experiment results show that water flooding with low injection pore volume ratio (IPVR) can improve reservoir quality since total porosity and connected porosity of samples rise after the flooding and the proportion of large pores also increases and heterogeneity of pore structure decreases. However, water flooding with high IPVR has reverse effects on pore structures. Polymer flooding reduces the total porosity, connected porosity, the percentage of small pores and enhances the heterogeneity of pore structures. It can be found that pore structures will change in fluid flooding and appropriate water injection can improve reservoir quality while excessive water injection may destroy the reservoir. Meanwhile, injected polymer may block throats and destroy reservoirs. The experimental results can be used as the basis for oil field development.


2014 ◽  
Vol 18 (01) ◽  
pp. 11-19 ◽  
Author(s):  
J.. Buciak ◽  
G.. Fondevila Sancet ◽  
L.. Del Pozo

Summary This paper deals with the learning curve of a five-plus-year polymer-flooding pilot conducted in a mature waterflood that includes, for example, several works related to injector and producer wells and reservoir management. The scope of this paper is to describe the learning curve during the last 5 years rather than the reservoir response of the polymer-flooding technique; focus is on the aspects related to reduce cost per incremental barrel of oil for a possible extension to other waterflooded areas of the field. Diadema oil field is in the San Jorge Gulf basin in the southern portion of Argentina. The field is operated by CAPSA, an Argentinean oil-producer company; it has 480 producer and 270 injector wells (interwell spacing is 250 m on average). The company has developed waterflooding over more than 18 years (today, this technique represents 82% of oil production in the field) and produces approximately 1600 m3/d of oil and 40 000 m3/d of gross production (96% water cut) with 38 400 m3/d of water injection. The reservoir that is polymer-flooded is characterized by high permeability (average of 500 md), high heterogeneity (10 to 5,000 md), high porosity (30%), very stratified sandstone layers (4 to 12 m of net thickness) with poor lateral continuity (fluvial origin), and 20 °API oil (100 cp at reservoir conditions). Diadema's polymer-flooding pilot started in October 2007 on five water injectors (it includes 13 injectors today) with an injected rate of 1000 m3/d (today, 2000 m3/d). Polymer solution is made with produced water (15,000 ppm brine) and 1,500 ppm of hydrolyzed polyacrylamide polymer reaching 15- to 20-cp fluid-injection viscosity. Oil-production rate from the original “central” producers (wells that are aided with 100% of polymer injection) has increased 100% at the same time as average reduction in water cut is approximately 15%. The main aspects presented in this work are depth profile modification with crosslinked gel injected along with polymer, use of “curlers” to regulate injection in multiple wells with one injection pump without shearing the polymer, and an improved technology on producer wells with progressing-cavity pumps to decrease shut-in time and number of pump failures. The plan for the future is to extend this project to other areas with the acquired knowledge and to improve different aspects, such as water quality and optimization of polymer plant operation. These improvements will allow the company to reduce operating costs per incremental barrel of oil.


2021 ◽  
Author(s):  
Abiola Oyatobo ◽  
Amalachukwu Muoghalu ◽  
Chinaza Ikeokwu ◽  
Wilson Ekpotu

Abstract Ineffective methods of increasing oil recovery have been one of the challenges, whose solutions are constantly sought after in the oil and gas industry as the number of under-produced reservoirs increases daily. Water injection is the most extended technology to increase oil recovery, although excessive water production can pose huge damage ranging from the loss of the well to an increase in cost and capital investment requirement of surface facilities to handle the produced water. To mitigate these challenges and encourage the utilization of local contents, locally produced polymers were used in polymer flooding as an Enhanced Oil Recovery approach to increase the viscosity of the injected fluids for better profile control and reduce cost when compared with foreign polymers as floppan. Hence this experimental research was geared towards increasing the efficiency of oil displacement in sandstone reservoirs using locally sourced polymers in Nigeria and also compared the various polymers for optimum efficiency. Starch, Ewedu, and Gum Arabic were used in flooding an already obtained core samples and comparative analysis of this shows that starch yielded the highest recovery due to higher viscosity value as compared to Ewedu with the lowest mobility ratio to Gum Arabic. Finally, the concentration of Starch or Gum Arabic should be increased for optimum recovery.


2012 ◽  
Vol 550-553 ◽  
pp. 834-837
Author(s):  
Ji Gang Wang ◽  
Quan Qing Du ◽  
Peng Wu ◽  
Shao Li Hu ◽  
Pan Niu

Keywords: Visco-elastic property; polymer flooding; oil recovery Abstract. Polymer flooding and ASP flooding has improved oil recovery a lot in Daqing oil field. In ASP flooding, the existence of alkali decreases the visco-elastic characteristic of polymer, which decreases the oil recovery of polymer flooding. The aim of this paper was to study the visco-elastic characteristic, shear resistance in high concentration and high molecular weight polymer flooding, and analyzed the suitable parameter of it .They can provide the theory of polymer flooding development and application research.


2008 ◽  
Vol 48 (1) ◽  
pp. 21
Author(s):  
Changhong Gao

Capture of emulsion droplets in porous media can be costly or beneficial. When produced water is injected into reservoir for pressure maintenance, the oil droplets in produced water can plug reservoir rocks and cause the well to lose injectivity. Enhanced oil recovery (EOR) technology takes advantage of this feature and plugs high-injectivity zones with emulsions. Previous studies reveal that interception and straining are the mechanisms of permeability decline. Established models rely on filtration data to determine key parameters. In this work, a network model is proposed to simulate capture of oil droplets in reservoir rocks and resultant permeability reduction. The model is validated with test data and reasonably good results are obtained. The simulation also reveals that the wettability of the tested porous media was altered by injection of emulsions. The new approach considers the characteristics of the porous media and incorporates the damage mechanisms, thus providing more scientific insights into the flow and capture of droplets in porous media.


2018 ◽  
Vol 785 ◽  
pp. 159-170
Author(s):  
Vadim Aleksandrov ◽  
Kirill Galinskij ◽  
Andrey Ponomarev ◽  
Vadim Golozubenko ◽  
Yuriy Sivkov

One of the most important aspects in the activities of oil companies in the Western Siberia is to improve the effectiveness of water-flooding as the main method of impact on the formation. This is due to the fact that at the present time reservoirs of a complex structure with difficult to recover reserves prevail among newly introduced development objects, the extraction of which is extremely difficult using a simple method of water injection volumes regulation. First of all, this refers to reservoirs of Jurassic deposits, which are characterized by the most complex geological structure and porosity and permeability properties. A promising direction in improving the water-flooding system at such objects is the use of physical and chemical technologies to enhance the oil recovery of formations, and primarily, referring to the diverter technology. The research objective is to evaluate the effectiveness of using “hard” type diverter compositions to enhance oil recovery of formations. With the help of detailed oil-field analysis and field-geophysical studies, the nature of the development of oil reserves for Jurassic development sites has been assessed.


2020 ◽  
Vol 194 ◽  
pp. 04046
Author(s):  
Xiulan Zhu ◽  
Yanlong Ran ◽  
Wenjie Guo ◽  
Ke Gai ◽  
Yanju Li ◽  
...  

With the long-term water injection development of Longdong oilfields, most of the oilfield blocks have been fully in the mid-high water cut period, and the amount of oil production wastewater is increasing year by year. In order to prevent the waste of resources and energy of oil production sewage, the oil production sewage after reaching the standard is treated for reinjection, which will ensure the sustainable development of the oil field. Oil production wastewater contains crude oil, solid-phase suspended solids and other pollutants, with high salinity, and problems such as difficulty in oil-water separation, sludge, scaling and corrosion. The sewage treatment system uses a multifunctional water treatment device to effectively remove oil and filter through the “special microorganism + air flotation + filtration” process, and build a sludge sewage tank for sludge discharge and backwashing. The reformed oil recovery wastewater reinjection treatment technology turns “sewage” into “clear flow”, reduces operating costs, improves wastewater treatment efficiency, and meets the water quality requirements of oilfield reinjection water.


2018 ◽  
Author(s):  
Ilyas Khurshid ◽  
Md Monwar Hossain ◽  
Abdulrahman Alraeesi ◽  
Ameera Fares ◽  
Fatima Albalushi ◽  
...  

2013 ◽  
Vol 631-632 ◽  
pp. 140-144
Author(s):  
Li Li

In this paper, the produced water in Daqing oilfield was detected, includes the viscosity and concentration ratio of living polymer (LH-1), interfacial tension and swelling rate of particle polymer (LHP-1). And its adaptability in low permeable fracture core was also tested. The results show that the injection property is good if the living polymer (LH-1) and the particle polymer (LHP-1) are used together, the volume-expansion particle polymer can effectively plugging the high permeable layer in bottom of the reservoir and improve water injection profile. The best injection volume of LH-1is 0.32 PV, and enhances oil recovery rate is 18.4%.


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