scholarly journals Performance Evaluation of STARPAM Polymer and Application in High Temperature and Salinity Reservoir

2018 ◽  
Vol 2018 ◽  
pp. 1-13 ◽  
Author(s):  
Chengli Zhang ◽  
Peng Wang ◽  
Guoliang Song

Based on the properties of high temperature and salinity reservoir, the water-soluble polymer with good heat resistance and salt tolerance can be obtained through copolymerization between 2-acrylamide-2-methyl sulfonate monomer (AMPSN) and acrylamide monomer (AM) in water. The star shaped stable complexes (STARPAM) with the star nucleus of β-CD are prepared by living radical polymerization, which can improve the viscosity and change the percolation characteristics of the polymer in porous media. In the article, the performance of the STARPAM (star-shaped polymer) with heat resistance and salt tolerance was evaluated by comparing the viscosification property, heat and salt resistance, calcium and magnesium tolerance, and long-term thermal stability of STARPAM (star-shaped polymer) with those of HPAM (partially hydrolyzed polyacrylamide) and MO-4000 (linear polymer). The results of physical simulation experiment showed that the viscosity of the STARPAM is 3.3 times that of MO-4000 and 4 times that of HPAM under the conditions of mineralization degree of 20000 mg/L, concentration of 1500 mg/L, and 75°C, which indicated that heat resistance and salt tolerance of the STARPAM are excellent. Oil displacement experiments showed that STARPAM can enhance oil recovery by 20.53% after water flooding, and the effect of oil displacement is excellent. At present, 19 wells were effective with a ratio of 95.2%. Compared with before treatment, the daily liquid production increased by 136 m3, daily oil production increased by 44.6 t, water cut decreased by 4.67 percentage points, and flow pressure decreased by 1.15 MPa.

2018 ◽  
Vol 15 (30) ◽  
pp. 380-386
Author(s):  
Y. V. SAVINYKH ◽  
L. D. LANG

Polymer flooding is technologically simple and highly effective method of enhanced oil recovery. The method is based on adding a small amount of polymer in conventional water flooding of oil reservoirs. The increase in viscosity and the reduction of the mobility of injected water are to equalize the displacement front by slowing the moving of water in the highly permeable zones and restricting the formation of water finger. These factors help to increase the sweep efficiency and oil-water displacement efficiency during flooding. Polymer flooding has been used successfully in clastic and carbonate reservoirs, as well as in low-permeability reservoirs such as a fractured basement. However, most of the current polymer gel used for control water flows are decayed by a high content of ions Ca2+ and Mg2+ in formation water or in injected water. Similarly, polymer gels lose their stability at high reservoir temperature (above 70°C). Developing water-soluble polymer, which does not change their rheological properties under high salinity and high temperature (over 100°C), is very important when producing offshore, where sea water is commonly used for flooding (high salinity of 30-40 g/L).


2021 ◽  
Vol 11 (4) ◽  
pp. 1905-1913
Author(s):  
Tagwa A. Musa ◽  
Ahmed F. Ibrahim ◽  
Hisham A. Nasr-El-Din ◽  
Anas. M. Hassan

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%.


Geofluids ◽  
2018 ◽  
Vol 2018 ◽  
pp. 1-11 ◽  
Author(s):  
Huiying Zhong ◽  
Qiuyuan Zang ◽  
Hongjun Yin ◽  
Huifen Xia

With the growing demand for oil energy and a decrease in the recoverable reserves of conventional oil, the development of viscous oil, bitumen, and shale oil is playing an important role in the oil industry. Bohai Bay in China is an offshore oilfield that was developed through polymer flooding process. This study investigated the pore-scale displacement of medium viscosity oil by hydrophobically associating water-soluble polymers and purely viscous glycerin solutions. The role and contribution of elasticity on medium oil recovery were revealed and determined. Comparing the residual oil distribution after polymer flooding with that after glycerin flooding at a dead end, the results showed that the residual oil interface exhibited an asymmetrical “U” shape owing to the elasticity behavior of the polymer. This phenomenon revealed the key of elasticity enhancing oil recovery. Comparing the results of polymer flooding with that of glycerin flooding at different water flooding sweep efficiency levels, it was shown that the ratio of elastic contribution on the oil displacement efficiency increased as the water flooding sweep efficiency decreased. Additionally, the experiments on polymers, glycerin solutions, and brines displacement medium viscosity oil based on a constant pressure gradient at the core scale were carried out. The results indicated that the elasticity of the polymer can further reduce the saturation of medium viscosity oil with the same number of capillaries. In this study, the elasticity effect on the medium viscosity oil interface and the elasticity contribution on the medium viscosity oil were specified and clarified. The results of this study are promising with regard to the design and optimum polymers applied in an oilfield and to an improvement in the recovery of medium viscosity oil.


Molecules ◽  
2021 ◽  
Vol 26 (24) ◽  
pp. 7468
Author(s):  
Xiaoqin Zhang ◽  
Bo Li ◽  
Feng Pan ◽  
Xin Su ◽  
Yujun Feng

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.


2011 ◽  
Vol 306-307 ◽  
pp. 654-657 ◽  
Author(s):  
Yu Wang ◽  
Zhi Yong Lu ◽  
Yu Gui Han ◽  
Yu Jun Feng ◽  
Chong Li Tang

Polymer flooding represents one of the most efficient processes to enhance oil recovery, but the poor thermostability and salt tolerance of the currently-used partially hydrolyzed polyacrylamide (HPAM) impeded its use in high-temperature and high-salinity oil reservoirs. “Smart” thermoviscosifying polymers (TVPs) may overcome the deficiencies of HPAM. Steady and dynamic rheological behaviors against temperature of a novel TVP were examined in this work in comparison with a commercial HPAM polymer. It was found when increasing temperature, both apparent viscosity and elastic modulus increase for TVP aqueous solution, but decrease for HPAM solution. The results indicate that TVP shows some potential to be used in enhancing oil recovery from high-temperature and high-salinity oil reservoirs.


SPE Journal ◽  
2010 ◽  
Vol 16 (01) ◽  
pp. 43-54 ◽  
Author(s):  
Guillaume Dupuis ◽  
David Rousseau ◽  
René Tabary ◽  
Bruno Grassl

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.


e-Polymers ◽  
2007 ◽  
Vol 7 (1) ◽  
Author(s):  
Huang Zhiyu ◽  
Lu Hongsheng ◽  
Zhang Tailiang

Abstract In order to enhance oil recovery in high-temperature and high-salinity oil reservoirs, the copolymeric microspheres containing acrylamide (AM), acrylonitrile (AN) and AMPS was synthesized by inverse suspension polymerization. The copolymeric microsphere was very uniform and the size could be changed according to the condition of polymerization. The lab-scale studies showed that the copolymeric microsphere exhibit good salt-tolerance and thermal-stability when immersed in 20×105 mg/L NaCl(or KCl) solution, 7500 mg/L CaCl2 (or MgCl2) solution or 2000 mg/L FeCl3 solution, respectively. The copolymeric microsphere showed satisfactory absorbency rates. The sand-pipes experiments confirmed that the average toughness index was 1.059. It could enhance the oil recovery by about 3% compared with the corresponding irregular copolymeric particle.


2021 ◽  
Vol 874 ◽  
pp. 45-49
Author(s):  
Ihsan Arifin ◽  
Grandprix Thomryes Marth Kadja ◽  
Cynthia L. Radiman

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.


2019 ◽  
Vol 2019 ◽  
pp. 1-11
Author(s):  
Peike Gao ◽  
Hongbo Wang ◽  
Guanxi Li ◽  
Ting Ma

With the development of molecular ecology, increasing low-abundance microbial populations were detected in oil reservoirs. However, our knowledge about the oil recovery potential of these populations is lacking. In this study, the oil recovery potential of low-abundance Dietzia that accounts for less than 0.5% in microbial communities of a water-flooding oil reservoir was investigated. On the one hand, Dietzia sp. strain ZQ-4 was isolated from the water-flooding reservoir, and the oil recovery potential was evaluated from the perspective of metabolisms and oil-displacing test. On the other hand, the strain has alkane hydroxylase genes alkB and P450 CYP153 and can degrade hydrocarbons and produce surfactants. The core-flooding test indicated that displacing fluid with 2% ZQ-4 fermentation broth increased 18.82% oil displacement efficiency, and in situ fermentation of ZQ-4 increased 1.97% oil displacement efficiency. Furthermore, the responses of Dietzia in the reservoir accompanied by the nutrient stimulation process was investigated and showed that Dietzia in some oil production wells significantly increased in the initial phase of nutrient injection and sharply decreased along with the continuous nutrient injection. Overall, this study indicates that Dietzia sp. strain has application potential for enhancing oil recovery through an ex situ way, yet the ability of oil recovery in situ based on nutrient injection is limited.


2015 ◽  
Vol 733 ◽  
pp. 144-147 ◽  
Author(s):  
Jiang Min Zhao ◽  
Tian Ge Li

This paper optimizes the design of the nature of each slug and the combination of slugs through theoretical calculations and laboratory experiments, which is the key to tremendously enhance the oil recovery with the oil-displacing method of multiple multi-slug combinations. When oil-displacing experiments with multiple multi-slug combinations are conducted on heterogeneous cores in the laboratory, it is necessary that each injected slug be designed rationally in their viscosity, volume, etc., with the view to guarantee the synchronous equi-fluidity mobility of each slug after water flooding. With the synergistic effect of a variety of oil-displacing agents, the remaining oil in each permeability layer can be dug, driven by overall piston.


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