Stable foam systems for improving oil recovery under high-temperature and high-salt reservoir conditions

Long-term thermal stability of surfactants under harsh reservoir conditions is one of the main challenges for surfactant injection. Most of the commercially available surfactants thermally degrade or precipitate when exposed to high-temperature and high-salinity conditions. In this work, we designed and synthesized three novel betaine-based polyoxyethylene zwitterionic surfactants containing different head groups (carboxybetaine, sulfobetaine, and hydroxysulfobetaine) and bearing an unsaturated tail. The impact of the surfactant head group on the long-term thermal stability, foam stability, and surfactant–polymer interactions were examined. The thermal stability of the surfactants was assessed by monitoring the structural changes when exposed at high temperature (90 °C) for three months using 1H-NMR, 13C-NMR, and FTIR analysis. All surfactants were found thermally stable regardless of the headgroup and no structural changes were evidenced. The surfactant–polymer interactions were dominant in deionized water. However, in seawater, the surfactant addition had no effect on the rheological properties. Similarly, changing the headgroup of polyoxyethylene zwitterionic surfactants had no major effect on the foamability and foam stability. The findings of the present study reveal that the betaine-based polyoxyethylene zwitterionic surfactant can be a good choice for enhanced oil recovery application and the nature of the headgroup has no major impact on the thermal, rheological, and foaming properties of the surfactant in typical harsh reservoir conditions (high salinity, high temperature).

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Laboratory Evaluation on Foaming Agent for High-Temperature and High-Salinity Reservoir

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.884-885.82 ◽

2014 ◽

Vol 884-885 ◽

pp. 82-86

Author(s):

Ji Chao Fang ◽

Cai Li Dai ◽

Kai Wang ◽

Qin Fang Ding ◽

Si Yu Wang

Keyword(s):

High Temperature ◽

Oil Recovery ◽

Foam Stability ◽

Pressure Rise ◽

Laboratory Evaluation ◽

Total Recovery ◽

Foaming Agent ◽

Reservoir Conditions ◽

Foam Flooding ◽

Enhance Oil Recovery

In order to further enhance oil recovery (EOR) of the high temperature and high salt oil fields by foam flooding, one foaming agent was screened by airflow method. The influence of oil-water and pressure on foamability and stability were evaluated,and oil displacement experiment was also conducted. The results show that CS-1 foaming agent has better foamability and stability than the others under the reservoir conditions (Temperature 110 °C, Salinity 11.52×104 mg/L, Ca2+&Mg2+ 7654 mg/L). The foam stability will be better as the pressure rise or be worse when it met the crude oil. Oil recovery was improved by 4.13% after waterflood and the total recovery is 60.75%.

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Polymers for EOR Application in High Temperature and High Viscosity Oils: Rock–Fluid Behavior

Energies ◽

10.3390/en13225944 ◽

2020 ◽

Vol 13 (22) ◽

pp. 5944

Author(s):

Rubén H. Castro ◽

Sebastián Llanos ◽

Jenny Rodríguez ◽

Henderson I. Quintero ◽

Eduardo Manrique

Keyword(s):

High Temperature ◽

Oil Recovery ◽

High Viscosity ◽

Oil Field ◽

Heavy Oils ◽

Displacement Efficiency ◽

Reservoir Conditions ◽

Oil Displacement Efficiency ◽

Sulfonated Polyacrylamide ◽

Total Dissolved Solid

Viscosity losses and high degradation factors have a drastic impact over hydrolyzed polyacrylamides (HPAM) currently injected, impacting the oil recovery negatively. Previous studies have demonstrated that biopolymers are promising candidates in EOR applications due to high thermochemical stability in harsh environments. However, the dynamic behavior of a biopolymer as scleroglucan through sandstone under specific conditions for a heavy oil field with low salinity and high temperature has not yet been reported. This work presents the rock–fluid evaluation of the scleroglucan (SG at 935 mgL−1) and sulfonated polyacrylamide (ATBS at 2500 mgL−1) to enhance oil recovery in high-temperature for heavy oils (212 °F and total dissolved solid of 3800 mgL−1) in synthetic (0.5 Darcy) and representative rock samples (from 2 to 5 Darcy) for a study case of a Colombian heavy oilfield. Dynamic evaluation at reservoir conditions presents a scenario with stable injectivity after 53.6 PV with a minimal pressure differential (less than 20 psi), inaccessible porous volume (IPV) of 18%, dynamic adsorption of 49 µg/g, and resistance and residual resistance factors of 6.17 and 2.84, respectively. In addition, higher oil displacement efficiency (up to 10%) was obtained with lower concentration (2.7 times) compared to a sulfonated polyacrylamide polymer.

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Experimental Investigation of Polymer-Coated Silica Nanoparticles for EOR under Harsh Reservoir Conditions of High Temperature and Salinity

Nanomaterials ◽

10.3390/nano11030765 ◽

2021 ◽

Vol 11 (3) ◽

pp. 765

Author(s):

Alberto Bila ◽

Ole Torsæter

Keyword(s):

High Temperature ◽

Silica Nanoparticles ◽

Oil Recovery ◽

Data Bank ◽

Sweep Efficiency ◽

Reservoir Conditions ◽

Wet Condition ◽

Incremental Oil Recovery ◽

Original Oil In Place

Laboratory experiments have shown higher oil recovery with nanoparticle (NPs) flooding. Accordingly, many studies have investigated the nanoparticle-aided sweep efficiency of the injection fluid. The change in wettability and the reduction of the interfacial tension (IFT) are the two most proposed enhanced oil recovery (EOR) mechanisms of nanoparticles. Nevertheless, gaps still exist in terms of understanding the interactions induced by NPs that pave way for the mobilization of oil. This work investigated four types of polymer-coated silica NPs for oil recovery under harsh reservoir conditions of high temperature (60 ∘C) and salinity (38,380 ppm). Flooding experiments were conducted on neutral-wet core plugs in tertiary recovery mode. Nanoparticles were diluted to 0.1 wt.% concentration with seawater. The nano-aided sweep efficiency was studied via IFT and imbibition tests, and by examining the displacement pressure behavior. Flooding tests indicated incremental oil recovery between 1.51 and 6.13% of the original oil in place (OOIP). The oil sweep efficiency was affected by the reduction in core’s permeability induced by the aggregation/agglomeration of NPs in the pores. Different types of mechanisms, such as reduction in IFT, generation of in-situ emulsion, microscopic flow diversion and alteration of wettability, together, can explain the nano-EOR effect. However, it was found that the change in the rock wettability to more water-wet condition seemed to govern the sweeping efficiency. These experimental results are valuable addition to the data bank on the application of novel NPs injection in porous media and aid to understand the EOR mechanisms associated with the application of polymer-coated silica nanoparticles.

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Laboratory Study on the Potential EOR Use of HPAM/VES Hybrid in High-Temperature and High-Salinity Oil Reservoirs

Journal of Chemistry ◽

10.1155/2013/927519 ◽

2013 ◽

Vol 2013 ◽

pp. 1-8 ◽

Cited By ~ 13

Author(s):

Dingwei Zhu ◽

Jichao Zhang ◽

Yugui Han ◽

Hongyan Wang ◽

Yujun Feng

Keyword(s):

Thermal Stability ◽

High Temperature ◽

Salinity Tolerance ◽

Oil Recovery ◽

High Salinity ◽

Oil Reservoirs ◽

Mechanical Degradation ◽

Core Flooding ◽

Reservoir Conditions ◽

Viscoelastic Surfactant

Polymer flooding represents one of the most efficient processes to enhance oil recovery, and partially hydrolyzed polyacrylamide (HPAM) is a widely used oil-displacement agent, but its poor thermal stability, salt tolerance, and mechanical degradation impeded its use in high-temperature and high-salinity oil reservoirs. In this work, a novel viscoelastic surfactant, erucyl dimethyl amidobetaine (EDAB), with improved thermal stability and salinity tolerance, was complexed with HPAM to overcome the deficiencies of HPAM. The HPAM/EDAB hybrid samples were studied in comparison with HPAM and EDAB in synthetic brine regarding their rheological behaviors and core flooding experiments under simulated high-temperature and high-salinity oil reservoir conditions (T: 85°C; total dissolved solids: 32,868 mg/L; [Ca2+] + [Mg2+]: 873 mg/L). It was found that the HPAM/EDAB hybrids exhibited much better heat- and salinity-tolerance and long-term thermal stability than HPAM. Core flooding tests showed that the oil recovery factors of HPAM/EDAB hybrids are between those of HPAM and EDAB. These results are attributed to the synergistic effect between HPAM and EDAB in the hybrid.

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Experimental study of the supercritical CO 2 diffusion coefficient in porous media under reservoir conditions

Royal Society Open Science ◽

10.1098/rsos.181902 ◽

2019 ◽

Vol 6 (6) ◽

pp. 181902 ◽

Cited By ~ 1

Author(s):

Junchen Lv ◽

Yuan Chi ◽

Changzhong Zhao ◽

Yi Zhang ◽

Hailin Mu

Keyword(s):

Porous Media ◽

Diffusion Coefficient ◽

Oil Recovery ◽

Carbon Capture ◽

Carbon Capture And Storage ◽

Elevated Pressure ◽

Experimental Results ◽

Saturated Porous Media ◽

Reservoir Conditions ◽

The Impact

Reliable measurement of the CO 2 diffusion coefficient in consolidated oil-saturated porous media is critical for the design and performance of CO 2 -enhanced oil recovery (EOR) and carbon capture and storage (CCS) projects. A thorough experimental investigation of the supercritical CO 2 diffusion in n -decane-saturated Berea cores with permeabilities of 50 and 100 mD was conducted in this study at elevated pressure (10–25 MPa) and temperature (333.15–373.15 K), which simulated actual reservoir conditions. The supercritical CO 2 diffusion coefficients in the Berea cores were calculated by a model appropriate for diffusion in porous media based on Fick's Law. The results show that the supercritical CO 2 diffusion coefficient increases as the pressure, temperature and permeability increase. The supercritical CO 2 diffusion coefficient first increases slowly at 10 MPa and then grows significantly with increasing pressure. The impact of the pressure decreases at elevated temperature. The effect of permeability remains steady despite the temperature change during the experiments. The effect of gas state and porous media on the supercritical CO 2 diffusion coefficient was further discussed by comparing the results of this study with previous study. Based on the experimental results, an empirical correlation for supercritical CO 2 diffusion coefficient in n -decane-saturated porous media was developed. The experimental results contribute to the study of supercritical CO 2 diffusion in compact porous media.

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