Studying the Effectiveness of Polyacrylamide (PAM) Application in Hydrocarbon Reservoirs at Different Operational Conditions (original) (raw)
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Heliyon
Polyacrylamides (PAM) are widely used as water-soluble polymers producing gel in oil reservoirs to assist in oil extraction from reservoirs with high levels of heterogeneity. These gels are susceptible to degradation due to hydrolysis in harsh reservoir conditions such as elevated temperature and salinity. This study uses a polymer integration technique in attempting to optimize the performance of PAM in the enhanced oil recovery process for reservoirs with high temperature and salinity. The results show that, at high temperature, hydrolysis is suppressed and gel stability is maintained via the addition of Polyvinylpyrrolidone (PVP) to PAM solutions. The optimum composition was identified as being 20/80 wt% PAM: PVP for oilfield operations at 90 C and a moderate salinity of 43,280 ppm. The degree of hydrolysis at 30 days was suppressed from 75% to 29.9%, with associated increases in viscosity from 11 to 38.2 mPa.s and from 18 to 44.3 mPa.s corresponding to rotational speeds of 30 and 10 rpm respectively. The issue of high salinity was considered by increasing the salinity of the optimised PAM: PVP mixture to 200,000 ppm. Under these conditions the degree of hydrolysis of the optimised solution increased from 29.9 to 46.9% and viscosity decreased from 38.2 to 28.6 and from 44.3 to 40.4 mPa.s for rotational speeds of 30 and 10 rpm respectively. 2-Acrylamido-2-MethylpropaneSulfonic acid (AMPS) was added to the mix to try to improve temperature stability. It was observed that, with an optimum composition of 18/72/10 wt% PAM:PVP:AMPS, the degree of hydrolysis decreased to 22% with viscosity levels of 30.6 and 22.8 mPa.s corresponding to rotational speeds of 10 and 30 rpm respectively.
Characterization and selection of polymers for future research on enhanced oil recovery
2008
Polymer flooding has been applied for petroleum recovery and the main results of this method are the effective increasing in oil production and the reduction of water circulation The objective of this work is to present a methodology for pre-selecting a polymer to be used in future research on enhanced oil recovery (EOR) by injecting polymer solution. A reservoir was selected and characterized. Seven samples of commercial partially hydrolyzed polyacrylamide (PHPA) were also selected and characterized. Polymer solutions were prepared and characterized in terms of filterability , viscosity, stability (under reservoir conditions) and mechanical degradation. Polymer-reservoir interaction was also investigated. The results showed that it is very useful to establish a methodology to pre-select the more suitable polymer for fluid injection operations in oil field. Besides, for the conditions used in this study, the best polymer presents hydrolysis degree of 30%, molar mass of 5·10 6 g /mol...
Characterization of polyacrylamides used in enhanced oil recovery
Journal of Applied Polymer Science, 1985
Polyacrylamides can be readily characterized using techniques such as IR spectroscopy, 13C-NMR, elementary analysis, TGA, and x-ray diffraction. The first three techniques can also be used quantitatively to measure the degree of hydrolysis of the polymers, without the need to know accurately the weight of the sample. The presence of inorganic salts, such as Na2SO4, Na4(CO3)SO4, and Na2CO3, is readily detected via IR or wide-angle x-ray diffraction. No evidence of crystallinity is found in the samples studied.
Journal of Applied Polymer Science, 2004
Acrylamide and tridecyl acrylate copolymers were synthesized by micellar copolymerization to obtain water-soluble, hydrophobically modified polymers. Rheological properties of the obtained polymer solutions were evaluated and compared to those of solutions of a commercial polyacrylamide currently used in the petroleum industry. The behavior of the copolymer solutions was studied as a function of the variation of hydrophobic monomer content incorporated in the copolymer as well as the salt content of the aqueous medium, for diluted and semi-diluted regimens. Comparative studies of such effects on the intrinsic viscosity and the critical concentration of those polymers were conducted. The increase in hydrophobic monomer content produced a sudden increase in the bulk and absolute viscosity of the polymeric solutions, a trend that was more intense from a certain concentration typical for each polymer. Salt addition led to lower bulk viscosity caused by a stronger interaction among hydrophobic groups, resulting from minimized exposure of such groups and water. The same effect was observed for the critical concentration. A comparison of the synthesized polymers with industrial polyacrylamide showed that the synthesized polymers were characterized by advantageously high shear strength and high salt resistance. However, in the absence of salts, higher copolymer amounts were needed to prepare solutions whose viscosity was the same as that of commercial polyacrylamide.
Nanoparticle modified polyacrylamide for enhanced oil recovery at harsh conditions
Silicon dioxide nanoparticles High temperature and high salinity Stability A B S T R A C T Silicon dioxide (SiO 2 ) nanoparticles (NPs) have been recently proposed to increase the performance of polyacrylamide (PAM) for enhanced oil recovery (EOR) applications. However, SiO 2 /PAM nanocomposites tend to agglomerate or even desposit under harsh conditions such as high temperature-high salinity (HT-HS), which greatly decreases the potential for future field applications. In this work, SiO 2 NPs were modified by (3-aminopropyl) triethoxysilane (M_SiO 2 ) to create positively charged active groups that enabled strong interaction with PAM functional groups, leading to high dispersion stability. Three samples including M_SiO 2 /PAM, SiO 2 /PAM and NP-free PAM were synthesised in-situ via free radical polymerisation, and their thermal stability, rheological properties and the effect of aging time were studied. It was found that M_SiO 2 could reduce the thermal degradation of the polymer and safeguard its backbone, resulting in much better thermal stability of PAM in harsh environments. After 90 days of aging, SiO 2 /PAM and NP-free PAM had 45 and 78% viscosity reduction; whereas only 10% reduction was observed for M_SiO 2 /PAM. In addition, core-flooding experiments showed that M_SiO 2 /PAM solutions produced more oil recovery than those from SiO 2 /PAM and NP-free PAM solutions at HT-HS condition.
All Days, 2011
Polyacrylamides (PAM) are widely used as water-soluble polymers producing gel in oil reservoirs to assist in oil extraction from reservoirs with high levels of heterogeneity. These gels are susceptible to degradation due to hydrolysis in harsh reservoir conditions such as elevated temperature and salinity. This study uses a polymer integration technique in attempting to optimize the performance of PAM in the enhanced oil recovery process for reservoirs with high temperature and salinity. The results show that, at high temperature, hydrolysis is suppressed and gel stability is maintained via the addition of Polyvinylpyrrolidone (PVP) to PAM solutions. The optimum composition was identified as being 20/80 wt% PAM: PVP for oilfield operations at 90 C and a moderate salinity of 43,280 ppm. The degree of hydrolysis at 30 days was suppressed from 75% to 29.9%, with associated increases in viscosity from 11 to 38.2 mPa.s and from 18 to 44.3 mPa.s corresponding to rotational speeds of 30 and 10 rpm respectively. The issue of high salinity was considered by increasing the salinity of the optimised PAM: PVP mixture to 200,000 ppm. Under these conditions the degree of hydrolysis of the optimised solution increased from 29.9 to 46.9% and viscosity decreased from 38.2 to 28.6 and from 44.3 to 40.4 mPa.s for rotational speeds of 30 and 10 rpm respectively. 2-Acrylamido-2-MethylpropaneSulfonic acid (AMPS) was added to the mix to try to improve temperature stability. It was observed that, with an optimum composition of 18/72/10 wt% PAM:PVP:AMPS, the degree of hydrolysis decreased to 22% with viscosity levels of 30.6 and 22.8 mPa.s corresponding to rotational speeds of 10 and 30 rpm respectively.
Journal of Petroleum Exploration and Production Technology, 2014
Recently, a renewed interest arises in the application of nanotechnology for the upstream petroleum industry. In particular, adding nanoparticles to fluids may drastically benefit enhanced oil recovery (EOR) and improve well drilling, by changing the properties of the fluid, rocks wettability alteration, advanced drag reduction, strengthening the sand consolidation, reducing the interfacial tension and increasing the mobility of the capillary trapped oil. In this study, we focus on roles of clay nanoparticles on polymer viscosity. Polymer-flooding schemes for recovering residual oil have been in general less than satisfactory due to loss of chemical components by adsorption on reservoir rocks, precipitation, and resultant changes in rheological properties. Rheological properties' changes are mainly determined by the chemical structure and mix of the polymers, surface properties of the rock, composition of the oil and reservoir fluids, nature of the added polymers and solution conditions such as salinity, pH and temperature. On the other hand, in this study, the focus is on viscosity and salinity of solutions polyacrylamide polymer solutions with different nanoparticles degrees and molecular weight. Results in certain range of clay concentration used in this test, the way of clay adding, have positive effects on solution viscosity. The effect of the polymer content and salinity were also to be investigated.
Oil & Gas Sciences and Technology – Revue d’IFP Energies nouvelles
Polymers applications have been progressively increased in sciences and engineering including chemistry, pharmacology science, and chemical and petroleum engineering due to their attractive properties. Amongst the all types of polymers, partially Hydrolyzed Polyacrylamide (HPAM) is one of the widely used polymers especially in chemistry, and chemical and petroleum engineering. Capability of solution viscosity increment of HPAM is the key parameter in its successful applications; thus, the viscosity of HPAM solution must be determined in any study. Experimental measurement of HPAM solution viscosity is time-consuming and can be expensive for elevated conditions of temperatures and pressures, which is not desirable for engineering computations. In this communication, Multilayer Perceptron neural network (MLP), Least Squares Support Vector Machine approach optimized with Coupled Simulated Annealing (CSA-LSSVM), Radial Basis Function neural network optimized with Genetic Algorithm (GA-R...
Journal of Oil, Gas and Petrochemical Sciences
Polyacrylamide (PAM) and partially hydrolysed polyacrylamide (HPAM) are the most used water soluble polymers in Enhanced Oil Recovery (EOR) applications because they represent a powerful means of increasing the viscosity of injection water and most importantly, improving mobility ratio. However, they exhibit limited stability in harsh reservoir conditions of elevated temperature and high salinity, which is a serious technical challenge. This paper describes a correlation analysis of the gradient of PAM hydrolysis and viscosity as a function of time, temperature (within the range of 25 to 93 o C) and salinity, to determine the safe maximum temperature point (SMTP) during improved and enhanced oil recovery (IOR/EOR) applications. The results indicate that different saline solutions such as NaCl, CaCl 2 and NaHCO 3 contains different SMTPs. At 5% NaCl, the SMTP was about 71 o C, while for a combined saline solution containing 9% NaCl and 1% CaCl 2 the SMTP was 78 o C while it was 65 o C for 3% NaCl and 1% NaHCO 3. However, the results indicate that a saline solution containing chemical properties of alkaline/acid behaviour, such as NaHCO 3 , hydrolysed more rapidly due to its lower SMTP value. Accordingly, this report provides insights into the chemistry behind PAM degradation and can help in predicting the maximum safe temperature point of polyacrylamide operations in the presence of brine at any ageing time of interest during chemical IOR/EOR techniques.