Further enhanced oil recovery by branched-preformed particle gel/HPAM/surfactant mixed solutions after polymer flooding in parallel-sandpack models

Water flooding is an economic method commonly used in secondary recovery, but a large quantity of crude oil is still trapped in reservoirs after water flooding. A deep understanding of the distribution of residual oil is essential for the subsequent development of water flooding. In this study, a pore-scale model is developed to study the formation process and distribution characteristics of residual oil. The Navier–Stokes equation coupled with a phase field method is employed to describe the flooding process and track the interface of fluids. The results show a significant difference in residual oil distribution at different wetting conditions. The difference is also reflected in the oil recovery and water cut curves. Much more oil is displaced in water-wet porous media than oil-wet porous media after water breakthrough. Furthermore, enhanced oil recovery (EOR) mechanisms of both surfactant and polymer flooding are studied, and the effect of operation times for different EOR methods are analyzed. The surfactant flooding not only improves oil displacement efficiency, but also increases microscale sweep efficiency by reducing the entry pressure of micropores. Polymer weakens the effect of capillary force by increasing the viscous force, which leads to an improvement in sweep efficiency. The injection time of the surfactant has an important impact on the field development due to the formation of predominant pathway, but the EOR effect of polymer flooding does not have a similar correlation with the operation times. Results from this study can provide theoretical guidance for the appropriate design of EOR methods such as the application of surfactant and polymer flooding.

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Enhanced oil recovery after polymer flooding by wettability alteration to gas wetness using numerical simulation

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

10.2516/ogst/2018029 ◽

2018 ◽

Vol 73 ◽

pp. 33 ◽

Cited By ~ 1

Author(s):

Kewen Li ◽

Changhui Cheng ◽

Changwei Liu ◽

Lin Jia

Keyword(s):

Numerical Simulation ◽

Enhanced Oil Recovery ◽

Oil Recovery ◽

Polymer Flooding ◽

Water Flooding ◽

Wettability Alteration ◽

Reservoir Permeability ◽

Gas Flooding ◽

Water Cut ◽

Enhance Oil Recovery

Polymer flooding, as one of the Enhanced Oil Recovery (EOR) methods, has been adopted in many oilfields in China and some other countries. Over 50% oil remains undeveloped in many oil reservoirs after polymer flooding. It has been a great challenge to find approaches to further enhancing oil recovery when polymer flooding is over. In this study, a new method was proposed to increase oil production using gas flooding with wettability alteration to gas wetness when polymer flooding has been completed. The rock wettability was altered from liquid- to gas-wetness during gas flooding. An artificial oil reservoir was constructed and many numerical simulations have been conducted to test the effect of wettability alteration on the oil recovery in reservoirs developed by water flooding and followed by polymer flooding. Production data from different scenarios, water flooding, polymer flooding after water flooding, gas flooding with and without wettability alteration after polymer flooding, were calculated using numerical simulation. The results demonstrate that the wettability alteration to gas wetness after polymer flooding can significantly enhance oil recovery and reduce water cut effectively. Also studied were the combined effects of wettability alteration and reservoir permeability on oil recovery.

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Enhanced oil recovery mechanisms of polymer flooding in a heterogeneous oil reservoir

Petroleum Exploration and Development ◽

10.1016/s1876-3804(21)60013-7 ◽

2021 ◽

Vol 48 (1) ◽

pp. 169-178

Author(s):

Xiangguo LU ◽

Bao CAO ◽

Kun XIE ◽

Weijia CAO ◽

Yigang LIU ◽

...

Keyword(s):

Enhanced Oil Recovery ◽

Oil Recovery ◽

Polymer Flooding ◽

Oil Reservoir ◽

Recovery Mechanisms

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Saturated carbon dioxide nanofluids enhanced oil recovery in carbonate reservoir cores using nuclear magnetic resonance

10.5194/egusphere-egu21-6762 ◽

2021 ◽

Author(s):

Yongsheng Tan ◽

Qi Li ◽

Liang Xu ◽

Xiaoyan Zhang ◽

Tao Yu

Keyword(s):

Carbon Dioxide ◽

Nuclear Magnetic Resonance ◽

Magnetic Resonance ◽

Enhanced Oil Recovery ◽

Oil Recovery ◽

Carbonate Reservoir ◽

Carbonate Reservoirs ◽

Residual Oil ◽

Core Flooding ◽

Nuclear Magnetic

The wettability, fingering effect and strong heterogeneity of carbonate reservoirs lead to low oil recovery. However, carbon dioxide (CO2) displacement is an effective method to improve oil recovery for carbonate reservoirs. Saturated CO2 nanofluids combines the advantages of CO2 and nanofluids, which can change the reservoir wettability and improve the sweep area to achieve the purpose of enhanced oil recovery (EOR), so it is a promising technique in petroleum industry. In this study, comparative experiments of CO2 flooding and saturated CO2 nanofluids flooding were carried out in carbonate reservoir cores. The nuclear magnetic resonance (NMR) instrument was used to clarify oil distribution during core flooding processes. For the CO2 displacement experiment, the results show that viscous fingering and channeling are obvious during CO2 flooding, the oil is mainly produced from the big pores, and the residual oil is trapped in the small pores. For the saturated CO2 nanofluids displacement experiment, the results show that saturated CO2 nanofluids inhibit CO2 channeling and fingering, the oil is produced from the big pores and small pores, the residual oil is still trapped in the small pores, but the NMR signal intensity of the residual oil is significantly reduced. The final oil recovery of saturated CO2 nanofluids displacement is higher than that of CO2 displacement. This study provides a significant reference for EOR in carbonate reservoirs. Meanwhile, it promotes the application of nanofluids in energy exploitation and CO2 utilization.

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Formulation development and visualized investigation of temperature-resistant and salt-tolerant surfactant-polymer flooding to enhance oil recovery

Journal of Petroleum Science and Engineering ◽

10.1016/j.petrol.2018.11.074 ◽

2019 ◽

Vol 174 ◽

pp. 584-598 ◽

Cited By ~ 14

Author(s):

Yanwei Wang ◽

Huiqing Liu ◽

Jing Wang ◽

Xiaohu Dong ◽

Fangxuan Chen

Keyword(s):

Oil Recovery ◽

Polymer Flooding ◽

Salt Tolerant ◽

Formulation Development ◽

Enhance Oil Recovery

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Design of Tailor-Made Water-Soluble Copolymers for Enhanced Oil Recovery Polymer Flooding Applications

Macromolecular Reaction Engineering ◽

10.1002/mren.201600020 ◽

2016 ◽

Vol 11 (1) ◽

Cited By ~ 7

Author(s):

Marzieh Riahinezhad ◽

Laura Romero-Zerón ◽

Neil McManus ◽

Alexander Penlidis

Keyword(s):

Enhanced Oil Recovery ◽

Oil Recovery ◽

Polymer Flooding ◽

Water Soluble

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Application of polymer flooding technology for enhanced oil recovery

Chemical Bulletin of Kazakh National University ◽

10.15328/cb644 ◽

2015 ◽

pp. 74-80

Author(s):

Sarkyt Kudaivergenov ◽

Iskander Gusenov ◽

Birzhan Zhappasbayev ◽

Alexey Shakhvorostov

Keyword(s):

Enhanced Oil Recovery ◽

Oil Recovery ◽

Polymer Flooding

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SURFACTANT-POLYMER FLOODING PERFORMANCE IN HETEROGENEOUS TWO-LAYERED POROUS MEDIA

IIUM Engineering Journal ◽

10.31436/iiumej.v12i1.37 ◽

2011 ◽

Vol 12 (1) ◽

pp. 31-38 ◽

Cited By ~ 3

Author(s):

Muhammad Taufiq Fathaddin ◽

Asri Nugrahanti ◽

Putri Nurizatulshira Buang ◽

Khaled Abdalla Elraies

Keyword(s):

Porous Media ◽

Oil Recovery ◽

Polymer Flooding ◽

Water Flooding ◽

Residual Oil ◽

Oil Saturation ◽

Reservoir Heterogeneity ◽

Residual Oil Saturation ◽

Layered Porous Media ◽

Multiple Porosity

In this paper, simulation study was conducted to investigate the effect of spatial heterogeneity of multiple porosity fields on oil recovery, residual oil and microemulsion saturation. The generated porosity fields were applied into UTCHEM for simulating surfactant-polymer flooding in heterogeneous two-layered porous media. From the analysis, surfactant-polymer flooding was more sensitive than water flooding to the spatial distribution of multiple porosity fields. Residual oil saturation in upper and lower layers after water and polymer flooding was about the same with the reservoir heterogeneity. On the other hand, residual oil saturation in the two layers after surfactant-polymer flooding became more unequal as surfactant concentration increased. Surfactant-polymer flooding had higher oil recovery than water and polymer flooding within the range studied. The variation of oil recovery due to the reservoir heterogeneity was under 9.2%.

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