Impact of different injection sites on the water and oil exchange in a fractured porous medium for different polymers: A visual study

Mao

J of Applied Polymer Sci

et al. 2019

In order to create an improved fracturing fluid, an organic amine boron composite crosslinker (ABC‐1) was prepared from boric acid, triethylenetetramine, ethylene glycol, and mannitol. It has no irritating smell and its synthesis is simple, making it suitable for large‐scale field applications. To illustrate the advantages of the new crosslinker, it was compared to the organic borate crosslinker prepared from boric acid, ethylene glycol, and mannitol. The sand‐carrying capacities, micronetwork structure, and rheological behaviors of fluids with these crosslinkers were investigated at 90, 100, and 110 °C. The results show that the additional BN r covalent bond in the ABC‐1 crosslinker leads to the formation of a denser network structure making it possible to reduce the amount of thickener by about 10%. The temperature resistance could also be enhanced at least 10 °C. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47675.

Section: Resultsmentioning

confidence: 99%

Improved fracturing fluid using: Organic amino boron composite crosslinker with BN covalent bond

Mao

J of Applied Polymer Sci

et al. 2019

“…Flow field reconstruction begins with a thorough recharge of the pre-pressurized zone, involving the injection of substantial volumes of oil-repellent fracturing fluids. In a single horizontal well, this may exceed 10,000 m 3 , while directional oil wells typically require between 2000 and 3000 m 3 . The primary objective of this injection is to restore formation pressure to over 95% of its original value.…”

Section: High-efficiency Re-fracturing Flooding Integration Processmentioning

confidence: 99%

“…During the initial phase of ultra-low permeability reservoir development, a sevenpoint well network was employed, utilizing a "water injection + fracturing" model [1][2][3]. However, this approach faced several challenges due to factors such as tight reservoir lithology and non-Darcy flow seepage [4].…”

Section: Introductionmentioning

confidence: 99%

Dramatically Enhancing Oil Recovery via High-Efficient Re-Fracturing Horizontal Wells in Ultra-Low Permeability Reservoirs: A Case Study in HQ Oilfield, Ordos Basin, China

He,

Huang,

Bai

et al. 2024

Processes

The ultra-low permeability oil reservoir in the HQ oilfield within the Ordos Basin exemplifies a classic “three-low” oil reservoir characterized by low pressure, low permeability, and low abundance. Upon the commencement of oil well production, substantial initial production decline and inadequate pressure maintenance levels are encountered. Consequently, these wells commonly face persistent low production issues resulting from ineffective water injection. Currently, the available technical approaches for repeated stimulation of such wells to enhance production and efficiency are limited, thereby restricting the effective utilization of the remaining oil reserves. In response to this challenge, this article presents an innovative technology tailored for high-efficiency re-fracturing to improve oil recovery in ultra-low permeability reservoirs. Grounded in the theory of multiple flow couplings and volume development, this technology introduces a novel integrated process encompassing seepage field reconstruction, fracturing, and oil displacement. This comprehensive approach culminates in an integrated energy replenishment methodology applicable throughout the entire reservoir’s life cycle. The proposed technology materializes a novel development method for ultra-low permeability reservoirs, centered on the principles of “seepage field reconstruction, integration of fracturing and oil displacement, multi-mode energy replenishment, and all-round displacement”. This integrated strategy ensures the efficient development of ultra-low permeability reservoirs. The successful implementation of this technology in the HQ oilfield is a notable achievement. Notably, the daily oil production of directional wells and horizontal wells significantly increased from 0.5 tons and 1.8 tons to 2.4 tons and more than 10 tons, respectively. Furthermore, the estimated ultimate recovery rate witnessed a substantial improvement from 5.2% to 17.3%. These compelling results underscore the potential of this technology in revitalizing the production of low-yield wells in ultra-low permeability reservoirs.

“…The fracture is a porous medium of the same porosity as the solid matrix but of very high permeability. This large difference in the permeability causes serious problems in oil recovery [20]. E. Holzbecher studied the effect of the permeability ratio on the global behaviour of a displacement of two fluids [21].…”

Section: Physical Modelmentioning

confidence: 99%

Numerical Study of Viscous Fingering in Heterogeneous Porous Media

2022

IJM

The displacement of a fluid by a second immiscible fluid is a fundamental process which is relevant for many technological applications, particularly in the petroleum industry. Water is the fluid widely used to push oil to production wells. During this immiscible displacement, a viscous fingering instability appears at the water-oil interface. This undesirable phenomenon leads to a low oil sweeping efficiency. To prevent this situation, techniques called EOR (Enhance Oil Recovery) are used. These methods have technical, economic and environmental disadvantages. Therefore, the objective of this work is to seek a rational use of EOR techniques by determining the right place and the appropriate time to operate them. In many previous studies, the effects of viscosity ratio, interfacial tension and flow rate are investigated. In this study, we numerically investigate the effect of the heterogeneity of the medium and the presence of the fracture on this phenomenon. Three different configurations are studied. The obtained results allowed to locate the regions where the behaviour of the instability varies during displacement in the porous medium, regions where instability is increasing and others where it remains constant. a qualitative comparison between the different cases is also made.