Processes
·
2025
·Vol. 13
·期 2
·457
·
IF 2.8
Li Wang,Hong He,Hua Wu,Zhi Luo,Zhongchen Gao,Jun Peng,Haixia Yin,Hao Lei
Water flooding is one of the most widely used secondary oil recovery methods for enhanced oil recovery (EOR). However, as a reservoir matures, excessive water production often accompanies oil production. To address this issue, the injection–production coupling technique (IPCT) has been proposed to control water production and improve oil recovery. Despite its practical application, the underlying mechanisms governing the injection–production process remain unclear. To investigate this, a transparent heterogeneous sand pack model and a visualization micro-model were employed to examine the impact of the injection–production mode on oil recovery and to uncover the mechanisms of enhanced oil recovery. The results indicate that, compared to the conventional continuous injection–production mode, both the fluid flow swept area and incremental oil recovery are significantly higher in the IPCT. Sweep efficiency improves by adjusting the injection–production streamlines and displacement directions. Notably, the oil displacement effect in the “stop injection” mode is more effective than in the “reduce injection” mode. These findings suggest that the coupling injection–production mode can efficiently recover residual oil in low permeability zones, thereby enhancing overall oil recovery.
研究领域:
石油工程
·
流体力学
✓ 已验证
产品关联
DOI
高影响因子
Processes
·
2024
·Vol. 12
·期 11
·2432
·
IF 2.8
Jinghui Li,Bochao Qu,Enlong Zhen,Shufen Ma,Yifei Liu
Multi-scale fractures in Northwest Oilfield are extremely developed. Fractures in both oil flow channels and water channels lead to the phenomenon of water channeling in the later stages of reservoir development, which may be affected by the bottom water cone. Gel plugging agents are widely used in the treatment of this phenomenon because of their low cost and high-water plugging efficiency. However, because there is often residual oil in small-scale fractures, the pressure law of different grades of differential fractures on gel is not clear, thus leading to low gel application efficiency and low oil recovery. There is still a lack of effective means through which to understand the regularity of shielding the remaining oil with gel strength and fractures of different grades. In this study, we conducted a novel analysis of the law of shielding oil production in fractured reservoirs. The gelling and rheological properties of anti-temperature gels (ATGs) with different strengths were studied. The plugging rate of oil phase was 96.39%, and that of water phase was 25.37%. ATG showed good oil–water selectivity. The influences of different grades of differential fractures on the production law of shielding the remaining oil were also studied, as well as the corresponding influence law chart. When the gel strength was in the range of 2.0–28.1 Pa and the fracture grade difference was 5–10, the recovery ratio was increased by 10.6–24%. The enhanced oil recovery can be quantitatively predicted by the scale of reservoir fractures and the strength of gel used. It has a certain guiding role for the field application of gel to efficiently shield residual oil in differential fractures.
研究领域:
石油工程
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
Energies
·
2019
·Vol. 12
·期 19
·3789
·
IF 2.707
Hong He,Yuqiu Chen,Qun Yu,Xianli Wen,Haocheng Liu
Surfactant–polymer (SP) flooding has significant potential to enhance oil recovery after water flooding in mature reservoirs. However, the economic benefit of the SP flooding process is unsatisfactory under low oil prices. Thus, it is necessary to reduce the chemical costs and improve SP flooding efficiency to make SP flooding more profitable. Our goal was to maximize the incremental oil recovery of the SP flooding process after water flooding by using the equal chemical consumption cost to ensure the economic viability of the SP flooding process. Thus, a systematic study was carried out to investigate the SP flooding process under different injection strategies by conducting parallel sand pack flooding experiments to optimize the SP flooding design. Then, the comparison of the remaining oil distribution after water flooding and SP flooding under different injection strategies was studied. The results demonstrate that the EOR efficiency of the SP flooding process under the alternating injection of polymer and surfactant–polymer (PASP) is higher than that of conventional simultaneous injection of surfactant and polymer. Moreover, as the alternating cycle increases, the incremental oil recovery increases. Based on the analysis of fractional flow, incremental oil recovery, and remaining oil distribution when compared with the conventional simultaneous injection of surfactant and polymer, the alternating injection of polymer and surfactant–polymer (PASP) showed better sweep efficiency improvement and recovered more remaining oil trapped in the low permeability zone. Thus, these findings could provide insights into designing the SP flooding process under low oil prices.Keywords:surfactant-polymer flooding;enhanced oil recovery;injection strategy;remaining oil distribution;heterogeneous reservoir
研究领域:
石油工程
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
ACS Omega
·
2025
·
IF 4.3
Xiongwei Liu,Yibo Feng,Xinping Xu,Faqiang Dang,Songyan Li
The crude oil reserves of fractured-vuggy reservoirs are large, but most of them are heavy oil and ultraheavy oil reservoirs. They have the characteristics of high heavy metal ion concentration, high asphaltene content, high viscosity and density, and deep burial. They are difficult to exploit. Therefore, it is necessary to reduce the viscosity of the heavy oil to improve crude oil recovery. In this paper, the use of a viscosity-reducing foamer is investigated. First, the optimal concentration screening, temperature resistance, salt resistance, aging resistance, viscosity-reducing ability, ability to reduce oil–water interfacial tension, and ability to reduce gas–liquid surface tension were evaluated for DXY-03 viscosity-reducing foamer and DXY-08 viscosity-reducing foamer. Then, an oil displacement experiment on the viscosity-reducing foam was carried out under different placement conditions by using a visual fractured-vuggy model. The experimental results showed that the DXY-08 viscosity-reducing foamer has better temperature resistance, salt resistance, viscosity-reducing ability, and ability to reduce gas–liquid interfacial tension than the DXY-03 viscosity-reducing foamer. Therefore, the DXY-08 viscosity-reducing foam was selected for visual oil displacement experiments. The results of the visual oil displacement experiments showed that the DXY-08 viscosity-reducing foamer has good flooding ability, can effectively use the remaining oil in the fractures and holes in the middle of a reservoir, can also block large-opening fractures, and can effectively use the remaining oil in small- and medium-sized fractures. In addition, a liquid phase and a gas phase are produced after the disproportionation of the viscosity-reducing foamer. The liquid phase can emulsify and reduce the viscosity of crude oil, and the gas phase replaces the oil remaining in the fracture hole at the top of the reservoir under the action of gravity, which greatly improves oil recovery.
研究领域:
石油工程
·
化学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
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