Improving the Viscosity of Partially Hydrolyzed Polyacrylamide (PHPAM) Solution for Enhanced Oil Recovery (EOR) Application

Enhanced Oil Recovery (EOR) is a promising technology for increasing crude oil production, especially from old wells. Polymer flooding is one of the techniques used in EOR in which the water-soluble polymer is added to increase the viscosity of the injected fluid. However, this technique has not been implemented in Indonesia due to the unavailability of locally-synthesized polymers. Therefore, this research aims to synthesize polyacrylamides and their partially-hydrolyzed derivatives and to study the possibility of their utilization for the EOR application. Various polymerization conditions using potassium persulfate (KPS) as initiators have been realized and the resulting polymers were characterized using FTIR spectroscopy and rheology measurement. It was found that higher monomer concentration resulted in higher viscosity-average molecular weight of polyacrylamide. Further study revealed that the hydrolysis of polyacrylamide by alkaline solution significantly increased the viscosity of 1000 ppm solution from 1.5 to 145.40 cP at room temperature, which is comparable to one of the commercial products. These results showed that the simple synthesis and hydrolysis method could be effectively used to produce water-soluble polymers for the EOR application.

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Enhancing Oil Recovery from Low-Permeability Reservoirs with a Thermoviscosifying Water-Soluble Polymer

Molecules ◽

10.3390/molecules26247468 ◽

2021 ◽

Vol 26 (24) ◽

pp. 7468

Author(s):

Xiaoqin Zhang ◽

Bo Li ◽

Feng Pan ◽

Xin Su ◽

Yujun Feng

Keyword(s):

Oil Recovery ◽

Water Soluble ◽

Oil Reservoirs ◽

Water Flooding ◽

Low Permeability ◽

Water Soluble Polymer ◽

Water Soluble Polymers ◽

Chemical Eor ◽

Incremental Oil Recovery ◽

Hydrolyzed Polyacrylamide

Water-soluble polymers, mainly partially hydrolyzed polyacrylamide (HPAM), have been used in the enhanced oil recovery (EOR) process. However, the poor salt tolerance, weak thermal stability and unsatisfactory injectivity impede its use in low-permeability hostile oil reservoirs. Here, we examined the adaptivity of a thermoviscosifying polymer (TVP) in comparison with HPAM for chemical EOR under simulated conditions (45 °C, 4500 mg/L salinity containing 65 mg/L Ca2+ and Mg2+) of low-permeability oil reservoirs in Daqing Oilfield. The results show that the viscosity of the 0.1% TVP solution can reach 48 mPa·s, six times that of HPAM. After 90 days of thermal aging at 45 °C, the TVP solution had 71% viscosity retention, 18% higher than that of the HPAM solution. While both polymer solutions could smoothly propagate in porous media, with permeability of around 100 milliDarcy, TVP exhibited stronger mobility reduction and permeability reduction than HPAM. After 0.7 pore volume of 0.1% polymer solution was injected, TVP achieved an incremental oil recovery factor of 13.64% after water flooding, 3.54% higher than that of HPAM under identical conditions. All these results demonstrate that TVP has great potential to be used in low-permeability oil reservoirs for chemical EOR.

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Flow of Hydrophobically Modified Water-Soluble-Polymer Solutions in Porous Media: New Experimental Insights in the Diluted Regime

SPE Journal ◽

10.2118/129884-pa ◽

2010 ◽

Vol 16 (01) ◽

pp. 43-54 ◽

Cited By ~ 30

Author(s):

Guillaume Dupuis ◽

David Rousseau ◽

René Tabary ◽

Bruno Grassl

Keyword(s):

Oil Recovery ◽

Polymer Concentration ◽

Adsorbed Layer ◽

Water Soluble ◽

Water Soluble Polymer ◽

Improved Oil Recovery ◽

Water Soluble Polymers ◽

Resistance Factors ◽

Soluble Polymers ◽

Hydrophobically Modified

Summary The specific molecular structure of hydrophobically modified water-soluble polymers (HMWSPs), also called hydrophobically associative polymers, gives them interesting thickening and surface-adsorption abilities compared with classical water-soluble polymers (WSPs), which could be useful in polymer-flooding and well-treatment operations. However, their strong adsorption obviously can impair their injectivity, and, conversely, the shear sensitivity of their gels can be detrimental to well treatments. Determining for which improved-oil-recovery (IOR) application HMWSPs are best suited, therefore, remains difficult. The aim of this work is to bring new insight regarding the interaction mechanisms between HMWSPs and rock matrix and the consequences concerning their propagation in reservoirs. A consistent set of HMWSPs with sulfonated polyacrylamide backbones and alkyl hydrophobic side chains together with an equivalent WSP was synthesized and fully characterized. HMWSP and WSP solutions were then injected in model granular packs. As expected, with HMWSPs, high resistance factors (or mobility reductions, Rm) were observed. Yet, within the limit of the injected volumes, the effluent showed the same viscosity and polymer concentration as the injected solutions. A first significant outcome concerns the specificities of the Rm curves during HMWSP injections. Rm increases took place in two steps. The first corresponded to the propagation of the viscous front, as observed with WSP, whereas the second was markedly delayed, occurring several pore volumes (PV) after the breakthrough. This result is not compatible with the classical picture of multilayer adsorption of HMWSPs but suggests that injectivity is controlled solely by the adsorption of minor polymeric species. This hypothesis was confirmed by reinjecting the collected effluents into fresh cores; no second-step Rm increases were observed. Brine injections in HMWSP-treated cores revealed high residual resistance factors (or irreversible permeability reductions, Rk), which can be attributed to the presence of thick polymer-adsorbed layers on the pore surface. Nevertheless, Rk values strongly decreased when increasing the brine-flow rate. This second significant outcome shows that the adsorbed-layer thickness is shear-controlled. These new results should lead to proposing new adapted filtration and injection procedures for HMWSPs, aimed, in particular, at improving their injectivity.

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Engineering Behavior and Characteristics of Water-Soluble Polymers: Implication on Soil Remediation and Enhanced Oil Recovery

Sustainability ◽

10.3390/su8030205 ◽

2016 ◽

Vol 8 (3) ◽

pp. 205 ◽

Cited By ~ 10

Author(s):

Shuang Cao ◽

Bate Bate ◽

Jong Hu ◽

Jongwon Jung

Keyword(s):

Enhanced Oil Recovery ◽

Soil Remediation ◽

Oil Recovery ◽

Water Soluble ◽

Water Soluble Polymers ◽

Soluble Polymers

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New insights into guar gum as environmentally friendly polymer for enhanced oil recovery in high-salinity and high-temperature sandstone reservoirs

Journal of Petroleum Exploration and Production Technology ◽

10.1007/s13202-020-01080-3 ◽

2021 ◽

Vol 11 (4) ◽

pp. 1905-1913

Author(s):

Tagwa A. Musa ◽

Ahmed F. Ibrahim ◽

Hisham A. Nasr-El-Din ◽

Anas. M. Hassan

Keyword(s):

High Temperature ◽

Enhanced Oil Recovery ◽

Oil Recovery ◽

Guar Gum ◽

High Salinity ◽

Environmentally Friendly ◽

Water Soluble ◽

Natural Polymer ◽

Soluble Polymer ◽

Water Soluble Polymer

AbstractChemical enhanced oil recovery (EOR) processes are usually used as additives for hydrocarbon production due to its simplicity and relatively reasonable additional production costs. Polymer flooding uses polymer solutions to increase oil recovery by decreasing the water/oil mobility ratio by increasing the viscosity of the displacing water. The commonly used synthetic water-soluble polymer in EOR application is partially hydrolyzed polyacrylamide (HPAM). However, synthetic polymers in general are not attractive because of high cost, environmental concerns, limitation in high temperature, and high-salinity environment. Guar gum is an environmentally friendly natural water-soluble polymer available in large quantities in many countries and widely used in various applications in the oil and gas industry especially in drilling fluids and hydraulic fracturing operations; however, very limited studies investigated on guar as a polymer for EOR and no any study investigated on its uses in high-temperature and high -salinity reservoirs. The objective of this study is to confirm the use of guar gum as a natural polymer for EOR applications in sandstone reservoirs and investigate its applicability for high-temperature and high-salinity reservoirs. The study experimentally investigated rheological characteristics of a natural polymer obtained from guar gum with consideration of high temperature (up to 210 °F) and high salinity (up to 20% NaCl) and tested the guar solution as EOR polymer. The results of this study show that the guar solution can be used as an environmentally friendly polymer to enhance oil recovery. Based on the results, it can be concluded that guar gum shows shear-thinning behavior and strongly susceptible to microbial degradation but also shows a very good properties stability in high temperature and salinity, where in low shear rate case, about 100 cp viscosity can be achieved at 210 °F for polymer prepared in deionized water. Guar polymer shows good viscosity in the presence of 20% NaCl where the viscosity is acceptable for temperature less than 190 °F. Also, the flooding experiment shows that the recovery factor can be increased by 16%.

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