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A Study on Alkali Consumption Regularity in Minerals of Reservoirs During Alkali(NaoH)/Surfactant/Polymer Flooding in Daqing Oilfield
Zhenhai JIANG,Qingjie ZHANG,Jianguang WEI,Yunsong GAO
Advances in Petroleum Exploration and Development , 2012, DOI: 10.3968/2404
Abstract: In the process of oil displacement of ASP (Alkali/ Surfactant/Polymer) flooding , when Alkali interacts with the fluid and minerals of the reservoir, the alkali is subject to be consumed. The consumption regularity is the key factor affecting ASP ingredient, injection plan, scaling regularity for production wells and oil displacement effectiveness. Therefore to study the alkali consumption is of great significance in guiding ASP ingredient, injection project design, and the analysis for oil displacement mechanism. In this paper, aiming at the main components of minerals in the reservoir in Daqing Oilfield, the laboratory study on static alkali consumption for five kinds of minerals (kaolinite, grundite, chlorite, feldspar and quartz) in ASP system and single component NaOH solution are done respectively. The alkali consumption regularities for five kinds of minerals in ASP and single component NaOH solution are concluded. The research indicates that the amount of alkali consumption for kaolinite, grundite, chlorite, feldspar and quartz is changing from larger to less accordingly, but is mainly caused by clay minerals; the average alkali consumption is 18.3% higher than that by matrix minerals. In single component NaOH solution, the alkali consumption styles of clay minerals and the matrix minerals take the chemical reaction as the lead, and the physical adsorption as the second. In ASP system solution, the alkali consumption style of clay minerals, takes the physical adsorption as the lead, and of matrix minerals takes the chemical reaction as the lead. In ASP solution, compared with single component solution, polymer and surfactant have the functions of restraint to alkali consumption in minerals of the reservoir, and the amount of alkali consumption decreases evidently. Key words: Alkali; Surfactan; Polymer; ASPl; Oil displacement
Surfactant and Surfactant-Polymer Flooding for Enhanced Oil Recovery  [cached]
Abhijit Samanta,Keka Ojha,Ashis Sarkar,Ajay Mandal
Advances in Petroleum Exploration and Development , 2011, DOI: 10.3968/10.3968/ j.aped.1925543820110201.608
Abstract: Investigation has been made to characterize the surfactant solution in terms of its ability to reduce the surface tension and the interaction between surfactant and polymer in its aqueous solution. A series of flooding experiments have been carried out to find the additional recovery using surfactant and surfactant polymer slug. Approximately 0.5 pore volume (PV) surfactant (Sodium dodecylsulfate) slug was injected in surfactant flooding, while 0.3 PV surfactant slug and 0.2 PV polymer (partially hydrolyzed polyacrylamide) slug were injected for surfactant-polymer flooding. In each case chase water was used to maintain the pressure gradient. The additional recovery in surfactant and polymer augmented surfactant flooding were found around 20% and 23% respectively.Key words: Enhanced oil recovery; Surfactant; Polymer; Surface tension; Flooding
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
An experimental study on ASP process using a new polymeric surfactant
Khaled Abdalla Elraies
Journal of Petroleum Exploration and Production Technologies , 2012, DOI: 10.1007/s13202-012-0039-5
Abstract: This paper presents an alternative chemical formulation using a new polymeric surfactant to improve the conventional alkali/surfactant/polymer (ASP) flooding. It is a one-component system for interfacial tension reduction and viscosity control. To simulate the conventional ASP flooding, the performance of the polymeric surfactant was studied in the absence and presence of sodium carbonate. The most outstanding feature of the new polymeric surfactant lies in its viscosity insensitivity towards an increasing alkali concentration up to 1.2 wt%. This feature makes the new formula superior to the conventional ASP process. A combination of alkali and surfactant with a concentration of 0.8 and 0.4 wt% was found to significantly reduce the interfacial tension while maintaining the desired solution viscosity. The optimal polymeric surfactant concentration was then validated in coreflood experiments using different surfactant concentrations. Using the optimum surfactant and alkali concentrations, tertiary oil recovery could reach 16.3 % of the original oil in place by injecting a 0.5 pore volume of the formulated slug. This makes the new polymeric surfactant promising because it has structural feature that can be modified to give a width range of interfacial tension reduction and viscosity control to suit reservoir conditions.
Recovery of Waterflood Residual Oil Using Alkali, Surfactant and Polymer Slugs in Radial Cores Récupération d'huile résiduelle par injection d'eau améliorée de produits alcalins, de tensio-actifs et de polymères dans des carottes radiales  [cached]
Nasr-El-Din H. A.,Hawkins B. F.
Oil & Gas Science and Technology , 2006, DOI: 10.2516/ogst:1991009
Abstract: An experimental study has been conducted to examine mobilization and recovery of waterflood residual oil in radial cores. Alkali, surfactant, and polymer slugs of various compositions, sizes and sequences were tested. Core flood experiments were conducted with unfired radial Berea sandstone disks at a flow rate of 8 cm3/h. David Lloydminster crude oil (total acid number of 0. 45 mg KOH/g oil) was used. The results of the present work showed that the composition and sequence of the injected chemical slug play an important role in mobilization and recovery of residual oil. For slugs lacking either mobility control, or low interfacial tension, no oil bank was formed and tertiary oil recovery was less than 20% Sor. A significant oil bank and tertiary oil recovery up to 70 % Sor were obtained with slugs having mobility control and low interfacial tension. However, maximum oil cut, incre-mental oil recovery and surfactant propagation were found to be functions of the alkali content in the slug. The incremental oil recovery, oil cut and slug injectivity greatly improved as the alkali concentration (sodium carbonate) in the combined slug was increased. A slight delay in surfactant breakthrough and a significantly slower rate of surfactant propagation were observed at higher sodium carbonate concentrations. Une étude expérimentale ayant pour but d'examiner la mobilisation et la récupération assistée d'huile résiduelle, à la suite d'un déplacement par l'eau en milieu poreux, a été conduite. Des bouchons de produit alcalin, de surfactant et de polymère, ayant des compositions, grosseurs et séquences d'injection variées, furent essayés. Les déplacements en milieu poreux furent conduits en utilisant des carottes de grès berea (non traités à haute température) et un débit de 8,0 cm3/h. Pour ce faire, on utilisa de l'huile de David Lloydminster (ayant un nombre acide de 0,45 mg KOH/g d'huile). Les résultats de ce travail ont démontré que la composition et séquence des bouchons chimiques jouent un r le important dans la mobilisation et la récupération des huiles résiduelles. Les bouchons qui avaient peu de contr le de mobilité, ou une tension d'interface basse, ne formaient pas de banque d'huile et la récupération tertiaire de l'huile était moins de 20% d'huile résiduelle. Une banque d'huile importante, ainsi qu'une récupération tertiaire allant jusqu'à 70% d'huile résiduelle, furent obtenues avec les bouchons possédant un bon contr le de mobilité ainsi qu'une tension d'interface basse. Cependant, la fraction maximale d'huile, la récupération accrue d'huile et la propa
Study of the multiple-profile control system to enhance oil recovery after polymer flooding
Q. H. Feng,X. C. Chen,M. D. Sun
Journal of Petroleum Exploration and Production Technologies , 2012, DOI: 10.1007/s13202-012-0029-7
Abstract: There is still half oil remaining in the reservoir after polymer flooding. This paper has carried out the laboratory studies on multi-profile control and displacement system to enhance oil recovery after polymer flooding. First of all, the multiple system comprising a gel particle, cross-linking agent and high effective surfactant, is screened according to specific criteria. Then the profile control experiments on binary and ternary system after polymer flooding are separately carried out to verify the potential of enhanced oil recovery. The results show that the multiple injection system not only blocks the high permeable layers and channels, but also makes full use of medium and low permeability layers, finally improving the whole sweep efficiency. Owing to the surfactant injection, the displacement efficiency is simultaneously improved to some extent, and thus greatly improves the oil recovery after polymer flooding.
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
Scientific research and field applications of polymer flooding in heavy oil recovery
Chang Hong Gao
Journal of Petroleum Exploration and Production Technologies , 2011, DOI: 10.1007/s13202-011-0014-6
Abstract: According to past experiences, polymer flood was not recommended for oil viscosity higher than 100 centipoises. In recent years, polymer flood becomes a promising technology for heavy oil recovery thanks to the widespread use of horizontal wells. This paper highlights the research advances of polymer in heavy oil recovery since 1977. In laboratory tests, polymer achieved tertiary recovery of more than 20% for heavy oil. A few field cases in China, Canada, Turkey, Suriname and Oman are also reviewed and analysed. Some field pilots have shown positive results. Field experiences indicate the major challenge facing polymer flooding effectiveness is to maintain good viscosity of polymer solution.
Polyvinyl Alcohol with Superior Flooding Properties to Enhance Oil Recovery Process  [cached]
O. Arjmand,S. Izadi,M. Mousavi,V. Rahmanian
Research Journal of Applied Sciences, Engineering and Technology , 2012,
Abstract: Polymer flooding is one of most important Enhance Oil Recovery (EOR) processes. This study concerns two key parameters influencing polymer flooding efficiency. As it is expected, some of key parameters such as: salinity and reservoir temperature and pressure, play important roles in improving oil recovery through polymer flooding. Regarding the fact that Hydrolyzed Poly Acryl Amid (HPAM) decomposes in high temperature and pressure conditions, only reservoirs with medium temperature and pressure are suitable for polymer flooding technique. On the other hand, viscosity of polymer solution decreases in high reservoir salinity, therefore HPAM is not effective for reservoirs with high salinity and temperature .We strongly believe that Poly vinyl Alcohol (PVA), as a viscous surfactant and IFT reducer, would be stable in extreme conditions of high salinity and high temperature (above 480o F) and therefore, it can be used for reservoirs with high salinity and temperature.
The Alkali/Surfactant/ Polymer Process: Effects of Slug Size, Core Length and a Chase Polymer Le procédé alkali/surfactant/polymère : effets de la taille du bouchon, de la longueur de la carotte et d'un polymère de déplacement  [cached]
Nasr-El-Din H. A.,Green K. A.,Schramm L. L.
Oil & Gas Science and Technology , 2006, DOI: 10.2516/ogst:1994021
Abstract: An experimental study was conducted to examine the effects of slug size, core length, and a chase polymer on the effectiveness of the alkali/surfactant/polymer (A/S/P) process in recovering waterflood residual oil. Core flood experiments were conducted with unfired linear Berea sandstone cores. The tertiary oil recovery, oil cut, pressure drop, and chemical propagation were measured for each flood. Tertiary oil recovery significantly increased with the slug size up to 0. 5 of a pore volume. Increasing the slug size further resulted in a smaller incremental increase in oil recovery. A slight increase in tertiary oil recovery was obtained when small size A/S/P slugs were followed with achase polymer having a viscosity higher than the slug. The lack of oil recovery with small A/S/P slugs was due to the consumption and dilution of the injected chemicals, especially the synthetic surfactant, due to adsorption and dispersion. Increasing the core length by a factor of 4. 5 (from 9 to 40. 6 cm) had no significant effect on tertiary oil recovery. Chemical propagation was found to be a function of core length (i. e. , core Peclet number) and the size of the chase polymer slug. Increasing core length and employing a chase polymer maintained the integrity of the A/S/P slug by decreasing the effect of dispersion and minimizing the influence of viscous fingering at the tail of the A/S/P slug. Une étude expérimentale a été effectuée pour examiner les effets de la taille du bouchon, de la longueur de la carotte et de l'emploi d'un polymère de déplacement sur l'efficacité du procédé A/S/P (alkali/surfactant/polymère) dans la récupération d'huile résiduelle par injection d'eau. Les expériences d'injection ont été faites avec des carottes rectilignes en grès de Berea vert. La récupération tertiaire du pétrole, la présence d'eau, la perte de charge et la propagation chimique ont été mesurées pour chaque injection. La récupération tertiaire du pétrole augmentait de manière significative avec la taille du bouchon, jusqu'à 0,5 du volume d'un pore. Ensuite, l'augmentation de la taille du bouchon provoquait une plus faible augmentation incrémentielle de la récupération. Un léger accroissement de la récupération tertiaire a été obtenu avec l'emploi de bouchons A/S/P de petite taille suivis d'un polymère de déplacement d'une viscosité supérieure à celle du bouchon. L'absence de récupération d'huile avec des bouchons A/S/P de petite taille était due à la perte et à la dilution des produits chimiques injectés, en particulier de l'agent tensio-actif synthétique, par adsorption et di
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