In-situ Fluid Phase Variation along the Thermal Maturation Gradient in Shale Petroleum Systems and Its Impact on Well Production Performance

Wang, Qianyou; Yang, Wei; Li, Yaohua; Jiang, Zhenxue; Wen, Ming; Zuo, Rusi; Wang, Xin; Xue, Zixin; Wang, Yaohua

doi:10.1007/s12583-022-1693-2

Cited by 4 publications

(5 citation statements)

References 70 publications

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“…33,34 The contact angle of the crude oil on the rock surface in the LSW-0.5Ca 2+ -3SO 4 2− water type is minimized, resulting in the strongest water wettability on the rock surface. The better water wettability is observed in LSW-0.5Ca 2+ -3SO 4 2− , which corresponds to the optimal composition of Ca 2+ and SO 4 2− ions. 6a that during the FW injection period, the oil recovery rates for the three cores stabilize at 33.57, 34.12, and 33.05%, respectively.…”

Section: Wettabilitymentioning

confidence: 77%

“…2− and stabilized at 74.26, 68.18, and 65.14°respectively. This indicates that as the SO 4 2− concentration in the solution increases, the contact angle decreases, suggesting an improvement in the water wettability of the rock surface. In reservoirs with mixed wettability, it is generally accepted that the more water wettability of the reservoir, the more favorable the recovery.…”

Section: Wettabilitymentioning

confidence: 95%

“… 1 − 3 In recent decades, low-permeability and extra-low-permeability sandstone reservoirs in the Ordos Basin have been mainly developed by water injection, with generally low recovery rates. 4 As one of the lowest cost technologies to improve recovery, low-salinity water flooding has been verified by a large number of experiments. 5 − 8 It has been gradually developed into a new technology for enhanced recovery by adjusting the ionic composition of injected water according to the mineral and fluid characteristics of the reservoir.…”

Section: Introductionmentioning

confidence: 98%

“…9,10 Numerous studies have demonstrated that lowsalinity water flooding can enhance recovery and have provided a variety of understanding of the recovery enhancement mechanism. 11−17 This article is licensed under CC-BY 4 It has been suggested by numerous researchers that the lowsalinity water flooding effect is due to the alteration of wettability. The change in wettability leads to the release of crude oil adsorbed on the rock surface, enhancing recovery.…”

Section: Introductionmentioning

confidence: 99%

“…With the rising global energy demand, the sustainable development of low-permeability and ultralow-permeability reservoirs is of great importance. − In recent decades, low-permeability and extra-low-permeability sandstone reservoirs in the Ordos Basin have been mainly developed by water injection, with generally low recovery rates . As one of the lowest cost technologies to improve recovery, low-salinity water flooding has been verified by a large number of experiments. − It has been gradually developed into a new technology for enhanced recovery by adjusting the ionic composition of injected water according to the mineral and fluid characteristics of the reservoir. , Numerous studies have demonstrated that low-salinity water flooding can enhance recovery and have provided a variety of understanding of the recovery enhancement mechanism. − …”

Section: Introductionmentioning

confidence: 99%

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Experimental Study on the Mechanism and Law of Low-Salinity Water Flooding for Enhanced Oil Recovery in Tight Sandstone Reservoirs

Fan,

Liu,

et al. 2024

ACS Omega

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Currently, research surrounding low-salinity water flooding predominantly focuses on medium-to high-permeability sandstone reservoirs. Nevertheless, further investigation is necessary to implement this technique with regard to tight sandstone reservoirs. The present study comprises a series of experiments conducted on the crude oil and core of the Ordos Chang 6 reservoir to investigate the influence of ionic composition on low-salinity water flooding in tight oil reservoirs. The change in wettability on the rock surface was analyzed by using the contact angle experiment. The change in recovery rate was analyzed using a core displacement experiment. The reaction between rock fluids was analyzed using an ion chromatography experiment. Additionally, a nuclear magnetic resonance (NMR) experiment was used to analyze the mobilization law of crude oil and the change in wettability on the scale of the rock core. This led to a comprehensive discussion of the law and mechanism of enhancing the recovery rate via low-salinity water flooding from various perspectives. Experiments show that low-salinity water flooding is an effective technique for enhancing recovery in tight sandstone reservoirs. Altering the ionic composition of injected water can improve the water wettability of the rock surface and enhance recovery. Decreasing the mass concentration of Ca 2+ or increasing the mass concentration of SO 4 2− can prompt the ion-exchange reaction on the rock surface and detachment of polar components from the surface. Consequently, the wettability of the rock surface strengthens, augmenting the recovery process. Nuclear magnetic resonance experiments evidence that low-salinity water injection, with ion adjustment, significantly alters the interactions between the rock and fluid in tight sandstone reservoirs. As a result, the T 2 signal amplitude decreases significantly, residual oil saturation reduces considerably, and the hydrophilic nature of the rock surface increases.

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Section: Wettabilitymentioning

confidence: 77%

Section: Wettabilitymentioning

confidence: 95%