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Experimental Study on the Properties and Displacement Effects of Polymer Surfactant Solution  [PDF]
Ke-Liang Wang,Lei-Lei Zhang,Xue Li,Yang-Yang Ming
Journal of Chemistry , 2013, DOI: 10.1155/2013/956027
Abstract: Based on the characteristics of oil reservoirs and the requirements of further enhancing oil recovery at high water cut stage of Pubei Oilfield, the displacement performance of polymer surfactant is evaluated. Reasonable injection parameters and oil displacement effects after water flooding are also researched. Compared with conventional polymer with intermediate molecular weight, polymer surfactant has the properties of higher viscosity at low concentration condition and lower interfacial tension. Laboratory experiments indicate that the displacement effect of polymer surfactant is much better than that of conventional polymer at a slug size of 0.57?PV. The oil recovery of polymer surfactant increases by more than 10% after water flooding. Considering the actual situation of low-permeability of Pubei Oilfield reservoirs, the system viscosity of 30?mPa·s is chosen. The corresponding concentration of Type III polymer surfactant is 600?mg/L and the injected slug is 0.57?PV and the oil recovery can be increased by 11.69%. 1. Introduction Polymer flooding has already entered the industrial application period in major reservoirs of Daqing Oilfield, and pilot trial has also been conducted in Pubei Oilfield, one of the many oilfields of Daqing Oilfield. Both laboratory and field data have shown that polymer flooding could improve oil recovery by nearly 10%, but this value was not perfect [1]. It was indicated that the oil recovery of ASP flooding was 20% higher than that of water flooding in Daqing Oilfield pilot tests [2, 3]. However, some problems such as formation damage due to alkali scale, production well pollution, and effluent treatment difficulties appeared in ASP development process [4, 5]. Experimental results showed that the oil recovery of binary combination flooding in major reservoirs increased by more than 15% [6]. However, the adsorption, diffusion, and migration properties of different chemical agents in porous media are quite different. This difference may result in the phenomenon of chromatographic separation and negative synergistic effect during the mixture system simultaneous flow [7]. In recent years, some functional groups have been grafted to hydrocarbon main chains to form a multivariate graft copolymer which is called functional polymer surfactant (also referred to as polymer surfactant) [8, 9]. As a new type of polymer, polymer surfactant is a single component oil displacement agent. In addition to the general nature of polymer, polymer surfactant can improve solubilization and emulsification capacity of crude oil in the absence of
Analysis and Formation of Hazardous Substances from Surfactant-Grafted Polyacrylamide Powder for Oilfield Production  [PDF]
Tingting Jiang, Haiyu Wang, Baohui Wang
Open Journal of Applied Sciences (OJAppS) , 2014, DOI: 10.4236/ojapps.2014.49047
Abstract: Surfactant-grafted Polyacrylamide (S-PAM) serves as a kind of economical and efficient flooding agents for its single component in the enhanced oil recovery in Daqing oilfield in China. The oil displacement experiments using S-PAM in multi-blocks revealed that in-use S-PAMs differ greatly from ordinary polymers. Aiming at making clear hazardous substances of S-PAM powder, this study characterized two commonly used S-PAMs in oil field through chemical analysis and instrumental analysis, and analyzed the toxic and hazardous gases of the two S-PAM powders.
Comparative studies on enhanced oil recovery by alkali–surfactant and polymer flooding
Abhijit Samanta,Achinta Bera,Keka Ojha,Ajay Mandal
Journal of Petroleum Exploration and Production Technologies , 2012, DOI: 10.1007/s13202-012-0021-2
Abstract: Chemical flooding methods are now getting importance in enhanced oil recovery to recover the trapped oil after conventional recovery. In the present study, a comprehensive study has been carried out on alkali, surfactant and polymer flooding. The chemicals with different compositions and combinations were used to recover the oil after conventional water flooding. It has been observed that increase in concentration of alkali, surfactant and polymer increases the additional recovery, but beyond a certain limit, the increase in recovery is only marginal. A series of flooding experiments using the combination of the above methods have been performed with additional recoveries more than 25 %. An analysis has been made on the relative cost of the different chemical slugs injected and the corresponding additional oil recovery. Based on the analysis, an optimum composition of the alkali–surfactant–polymer system has been recommended.
The Research on Weak Alkali ASP Compound Flooding System for Shengli Heavy Oil  [cached]
CHEN Ting,ZHANG Guicai,GE Jijiang,YANG Hong
Advances in Petroleum Exploration and Development , 2013, DOI: 10.3968/j.aped.1925543820130501.1123
Abstract: In order to avoid the disadvantages caused by strong alkali used in enhanced oil recovery, sodium metaborate was compounded with nonionic surfactant nonylphenol polyoxyethlene polyoxypropylene ether sulfate and hydrolyzed polyacrylamide for the first time as a chemical displacement agent for Shengli heavy oil. The interfacial tension between crude oil and aqueous solutions, emulsification tests, microscopic displacement properties and sandpack flooding were investigated. It can be observed that the interfacial tension was reduced to ultra-low value due to the synergy effect between the weak alkali and surfactant. The microscopic displacement tests showed that there was an optimum surfactant concentration for alkali-surfactant flooding system to obtain larger sweep efficiency. And the recovery efficiency can be further increased by addition of hydrolyzed polyacrylamide. The oil recovery increased with the increasing of hydrolyzed polyacrylamide concentration. The newly designed compound system was proven to have the application potential on pilot tests. Key words: Weak alkali; Sodium metaborate; Compound flooding system; Nonylphenol polyoxyethlene polyoxypropylene ether sulfate; Heavy oil
The Performance of Polymer Solution Added with Viscosity Stabilizer and the Evaluation of Its Oil Displacement Efficiency in Daqing Oilfield  [cached]
Jianguang WEI,Qingjie ZHANG,Zhenhai JIANG,Haijun ZHANG
Advances in Petroleum Exploration and Development , 2012, DOI: 10.3968/2401
Abstract: Aiming at the low viscosity of polymer solution, which is compounded with fresh water but diluted with produced water, and at the problems concerning oil displacement efficiency, an onsite test on polymer solution with viscosity stabilizer (PSVS) is carried out. As a result, it has great and guiding significance to the application and popularization of viscosity stabilizer by studying the performance of polymer solution with viscosity stabilizer and its influence on oil displacement efficiency. In this paper, aiming at two different kinds of polymer solutions among which one is compounded with fresh water but diluted with fresh produced water and the other with aerated produced water, two laboratory evaluative tests concerning viscosity stabilization, anti-shear stability, fluidity, and absorbability of polymer solution as well as its oil displacement efficiency are done. The results of onsite application of PSVS are traced and analyzed. The viscosity stabilization of the polymer solution adding with viscosity stabilizer becomes much better than that of the normal polymer solution. The resistance and the residual resistance factors, the static oil sand adsorption rate and the dynamic core adsorption rate of the solution are all increased markedly. The working viscosity and oil displacement efficiency are improved markedly as well. In comparison with the polymer solution diluted with fresh produced water, the polymer solution diluted with aerated produced water is much better in terms of viscosity stabilization. Comparing with the normal polymer solution with viscosity stabilizer before sheared, the polymer solution which is sheared before adding with viscosity stabilizer performs obviously better in terms of viscosity stability. In contrast to the adjacent block injected with normal polymer solution, the block under onsite flooding test with injection of PSVS features that the average injection pressure increases slightly but keeps steady, the recovery speed of the average monthly water cut of production wells slows down, the thickness of the absorptive layers increases, and the periodic recovery rate improves as well. Key words: Polymer solution; Viscosity stabilizer; Daqing oilfield
Research and Application of CO2 Flooding Enhanced Oil Recovery in Low Permeability Oilfield  [PDF]
Qigui Cheng, Zhongxin Li, Guangshe Zhu, Hongtao Zhang
Open Journal of Geology (OJG) , 2017, DOI: 10.4236/ojg.2017.79095
Abstract: This paper discusses the new progress and field application of CO2 flooding in low permeability reservoirs enhanced oil recovery. The study shows that CO2 flooding can improve the oil recovery rate of low permeability oilfield by more than 10%. The practice shows that the liquid CO2 injection in low permeability reservoir is easier than water injection, and the reservoir generally has better CO2 storage.
Feasibility Study of Secondary Polymer Flooding in Henan Oilfield, China  [cached]
Feng-lan ZHAO,Ji-rui HOU,Hong-sheng LI,Jing Lü
Advances in Natural Science , 2009, DOI: 10.3968/25
Abstract: After polymer flooding, it is necessary to find relay technology to retain oil yield. In this paper, laboratory experiments were conducted to investigate feasibility of secondary polymer flooding, in which injecting more polymer with higher concentration and relative molecular mass. It is necessary to determine enhanced recovery range and optimum concentration. With microscopic visible glass physical models, further start up of oil drops with secondary polymer can be observed distinctly. In the mean time, macroscopic heterogeneous core tests were carried out with permeability range of 2, 5 and 8. Polymer concentration effective and economical for flooding is optimized. Ii is shown that 3%~8% of further enhanced recovery and 20% decreased water cut can be obtained, and water profile can be improved to some extend after secondary polymer flooding. Thence, it is proved that secondary polymer injection after primary polymer can indeed further improve recovery and the technology of secondary flooding is feasible. Moreover, laboratory optimum concentration of 2200mg/L is determined. On the basis of laboratory results, from 2007 to 2008, filed trial with above optimum parameters were implemented. Up to 2008.12, water cut decreased from 92% to 83%, and cumulative increased crude oil of 5.71×104t.The success of secondary polymer flooding technology provides reference for the development of oil fields after primary polymer flooding in China and other regions in the whole world. Key words: secondary polymer flooding; feasibility study; microscopic mechanism; polymer concentration optimization; after polymer flooding
The Outline and General Comments about the Advance of the Resevoir Geophysics Project Implemented in Daqing Oilfield

LI You-ming,

地球物理学进展 , 2006,
Abstract: Shortly after the constitution of this project,in order to verify the feasibility of the theoretical research implementation,we proposed an additional requirement of direct involving in the production of oil and gas reservoirs in the outer part and deep part of Daqing,so that the overall merit of both theoretical research and practical application of this project can be improved.With the successful construction of PC-clusters and development of the seismic data parallel processing system plus assistant software packages in 1998,we built up the 3D wave equation pre-stack depth migration algorithm and the corresponding software in 2000,which is synchronous with international seismic exploration community.Such an achievement greatly improves the capability of seismic imaging in China.In the year of 1999,we assembled an eight-node PC-cluster and processed 150 km-long seismic profiles.In paticular,on the depth map of line 82,we clearly imaged the internal structure and fault character of an uplift in a depression area.After a rearrangement of 3D seismic exploration and with many research works,a great break through was achieved accomanying the drilling of the Xushen No.1 well and leading to the discovery of the huge gas field in Daqing.This success remarkably improves the continuable development foreground of Daqing oilfield.We have also built up two reservoir geophysics research centers in Beijing and Daqing,respectively.It has been proved that proper and reasonable research organization and activity will benefit the integration and application of the products of a great scientific project,and is key to make progress with combined efforts consecutively and efficiently.

CHEN Lin,SUI Xin-guang,TAO Jia-sheng,LI Fu-jun,

腐蚀科学与防护技术 , 2007,
Abstract: By chemical examination in laboratory and test in situ, we found that the CI^- content and SO^2-4 content are higher in Daqing oilfield, and the variation of the soil resistivity is bigger. The soils show strong corrosivity along longitudinal depth to steel equipments. By means of contact test with a reference electrode underground, we measured the distribution of casing protection potential along vertical depth. The results indicate that the casing protection potential curve is smooth, and the protection potential is lower than -850 mV. The casing protection current can polarize up to 10000 cm in depth. The bracelet anode and the casing can installed or repaired simultaneously in the fled with no additional troubles and cost to the conventional field operation, therefore, it is of applicable value.
Preliminary Study of Alkali Activation of Basalt: Effect of NaOH Concentration on Geopolymerization of Basalt  [PDF]
Mohamed El-Shahte Ismaiel Saraya, Ezzat El-Fadaly
Journal of Materials Science and Chemical Engineering (MSCE) , 2017, DOI: 10.4236/msce.2017.511006
Abstract: The main objective of this study is to examine the possibility of using fresh basalt powder in the preparation of geopolymer pastes. Four NaOH concentrations of 2.5, 5, 7.5 and 10 M were used to alkali activation of basalt. In addition, effect of curing temperature at ambient, 45°C and 65°C were studied. The geopolymer pastes were investigated using FTIR, XRD and SEM-EDS techniques as well as compressive strength up to 90 days. The results were shown the compressive strength of prepared geopolymer increased with concentration of alkali activator up to 90 days. On the other hand, the compressive strength of prepared geopolymer pastes were improved with increased curing temperature. The results showed that there was a change in the chemical and mineral structure, due to the reaction of the sodium hydroxide with the different minerals of the basalt. In addition, the Na/Al and Si/Al ratios were completely different from that of the raw basalt. The geopolymerization reactions occurred at the surface basalt and the unreacted basalt particles actually play a supporting role in the geopolymer properties.
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