Smart mobility control agent for enhanced oil recovery during CO2 flooding in ultra-low permeability reservoirs

With the shortage of recoverable reserves in conventional oil reservoirs, the development of low-permeability oil reservoirs has received more and more attention. The oil recovery of low-permeability reservoirs can be significantly improved by CO2 flooding, as it can effectively supply formation energy. CO2 flooding is an effective technology for increasing oil production in low-permeability reservoirs. However, because of the heterogeneity of the reservoir and the effect of natural fractures, CO2 gas channelling easily occurs during CO2 flooding, seriously reducing CO2 flooding effect. In this study, the gas channelling technology of acid-resistant gel foam was investigated. Preferred acid-resistant gel foam system formula was found as 0.1% by mass of AOS foaming agent with 0.3% to 0.4% by mass of instant HPAM polymer and 1% to 2% by mass of water-soluble phenolic resin crosslinking agent. This system still has a good foaming ability and blocking performance under at pH=2 and a salinity of 10×104 mg/L. After 60 days of aging under oil reservoir conditions, there is no obvious water separation, and the plugging strength retention rate reached more than 60%. The gel foam channelling system can be applied to highly heterogeneous and low permeability reservoirs with a permeability gradient higher than 14 and can increase the recovery rate by more than 20% based on the CO2 flooding. Acid-resistant gel foam channelling technology can effectively inhibit CO2 gas channelling and improve CO2 flooding effect in low permeability reservoirs.

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Enhanced Oil Recovery by a Suspension of Core-Shell Polymeric Nanoparticles in Heterogeneous Low-Permeability Oil Reservoirs

Nanomaterials ◽

10.3390/nano9040600 ◽

2019 ◽

Vol 9 (4) ◽

pp. 600 ◽

Cited By ~ 2

Author(s):

Long ◽

Wang ◽

Zhu ◽

Huang ◽

Leng ◽

...

Keyword(s):

Enhanced Oil Recovery ◽

Newtonian Fluid ◽

Oil Recovery ◽

Polymeric Nanoparticles ◽

Low Permeability ◽

High Permeability ◽

Permeability Ratio ◽

Nanoparticle Suspension ◽

Shear Rates ◽

Low Permeability Reservoirs

Polymeric nanoparticle suspension is a newly developed oil-displacing agent for enhanced oil recovery (EOR) in low-permeability reservoirs. In this work, SiO2/P(MBAAm-co-AM) polymeric nanoparticles were successfully synthesized by a simple distillation–precipitation polymerization method. Due to the introduction of polymer, the SiO2/P(MBAAm-co-AM) nanoparticles show a favorable swelling performance in aqueous solution, and their particle sizes increase from 631 to 1258 nm as the swelling times increase from 24 to 120 h. The apparent viscosity of SiO2/P(MBAAm-co-AM) suspension increases with an increase of mass concentration and swelling time, whereas it decreases as the salinity and temperature increase. The SiO2/P(MBAAm-co-AM) suspension behaves like a non-Newtonian fluid at lower shear rates, yet like a Newtonian fluid at shear rates greater than 300 s−1. The EOR tests of the SiO2/P(MBAAm-co-AM) suspension in heterogeneous, low-permeability cores show that SiO2/P(MBAAm-co-AM) nanoparticles can effectively improve the sweep efficiency and recover more residual oils. A high permeability ratio can result in a high incremental oil recovery in parallel cores. With an increase of the permeability ratio of parallel cores from 1.40 to 15.49, the ratios of incremental oil recoveries (low permeability/high permeability) change from 7.69/4.61 to 23.61/8.46. This work demonstrates that this SiO2/P(MBAAm-co-AM) suspension is an excellent conformance control agent for EOR in heterogeneous, low-permeability reservoirs. The findings of this study can help to further the understanding of the mechanisms of EOR using SiO2/P(MBAAm-co-AM) suspension in heterogeneous, low-permeability reservoirs.

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Worm-Like Micelles as a Mobility Control Agent for Chemical Enhanced Oil Recovery

10.2118/176075-ms ◽

2015 ◽

Cited By ~ 4

Author(s):

S. Kumar ◽

Mariyamni Awang ◽

Shuaib Ahmed ◽

Naeem Ul. hussain Dehraj ◽

Yasir Sheikh Saleem

Keyword(s):

Enhanced Oil Recovery ◽

Oil Recovery ◽

Control Agent ◽

Mobility Control

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Swelling Mechanism of Core–Shell Polymeric Nanoparticles and Their Application in Enhanced Oil Recovery for Low-Permeability Reservoirs

Energy & Fuels ◽

10.1021/acs.energyfuels.9b00131 ◽

2019 ◽

Vol 33 (4) ◽

pp. 3077-3088 ◽

Cited By ~ 2

Author(s):

Yunqian Long ◽

Xiaohe Huang ◽

Ying Gao ◽

Liqiao Chen ◽

Fuquan Song ◽

...

Keyword(s):

Enhanced Oil Recovery ◽

Oil Recovery ◽

Polymeric Nanoparticles ◽

Core Shell ◽

Low Permeability ◽

Swelling Mechanism ◽

Low Permeability Reservoirs

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Study on three phase foam for Enhanced Oil Recovery in extra-low permeability reservoirs

Oil & Gas Science and Technology – Revue d’IFP Energies nouvelles ◽

10.2516/ogst/2018059 ◽

2018 ◽

Vol 73 ◽

pp. 55 ◽

Cited By ~ 2

Author(s):

Ming Zhou ◽

Juncheng Bu ◽

Jie Wang ◽

Xiao Guo ◽

Jie Huang ◽

...

Keyword(s):

Enhanced Oil Recovery ◽

Oil Recovery ◽

Foam Stability ◽

Temperature Tolerance ◽

Resistance Coefficient ◽

Low Permeability ◽

Displacement Efficiency ◽

Three Phase ◽

Profile Control ◽

Low Permeability Reservoirs

Poly (MSt-MMA) nanosphere as foam stabilizing agent was synthesized by emulsion polymerization. The three phase foam was prepared with Disodium 4-Dodecyl-2,4′-Oxydiben Zenesulfonate (DOZS) as foaming agent, Hydrolyzed Polyacrylamide (HPAM) and synthesized poly (MSt-MMA) nanospheres as the mixed foam stabilizing agents. It had outstanding foaming performance and foam stability. The optimal three phase foam system consisting of 0.12 wt% HPAM, 0.04 wt% poly (MSt-MMA) nanospheres and 0.12 wt% DOZS by orthogonal experiment, had high apparent viscosity, which showed that three components had a very good synergistic effect. The three phase foam’s temperature tolerance and salt tolerance were researched in laboratory tests. Flooding oil experiment showed that the average displacement efficiency of three phase foam system was 16.1 wt% in single core experiments and 21.7 wt% in double core experiments. Resistance coefficient of low permeability core was more than those of high permeability core, but their residual resistance coefficients were small. The results of core experiment and pilot test indicated that the three phase foam had good profile control ability and generated low damage to the low permeability layer for extra-low permeability reservoirs. Three phase foam flooding has great prospects for Enhanced Oil Recovery (EOR) in extra-low permeability reservoirs.

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