Pore-scale experimental investigation of microscopic formation mechanism of remaining shale oil and trapped CO2 during water-supercritical CO2 flooding

Geoenergy Science and Engineering, Journal Year: 2025, Volume and Issue: unknown, P. 213684 - 213684

Published: Jan. 1, 2025

Language: Английский

Quantitative Evaluation of Residual Acid Invasion and Flowback in Fractured-Vuggy Carbonate Reservoirs Using Microfluidics

Energies, Journal Year: 2025, Volume and Issue: 18(5), P. 1162 - 1162

Published: Feb. 27, 2025

Acid fracturing has become a crucial technology for developing carbonate reservoirs, playing particularly significant role in enhancing oil and gas recovery. However, the retention flowback behaviors of residual acid fractured-vuggy reservoirs after remain poorly understood, this uncertainty significantly hinders efficient development such reservoirs. In study, micro-computed tomography images rocks were used to extract actual fracture–vug structures. A microscopic flow model was then designed fabricated using wet etching techniques. Microfluidic experiments performed investigate invasion behavior within these This study introduces novel approach by integrating fracture-vuggy structures from micro-CT into microfluidic model, providing more realistic representation compared previous studies that relied on simplified or idealized geometries. Additionally, coefficient (the ratio invaded area total pore area) rate proportion expelled during flowback) introduced quantitatively assess efficiency under varying rates, viscosities, presence absence surfactants. The results demonstrate increases with injection rate, while decreases as is reduced. higher viscosity phase slower due increased resistance micro model. final lower phase. addition surfactants enhances flowback, increasing up 5% 3%.

Language: Английский

Experimental investigation of the formation and distribution of remaining oil from pore scale to core scale during supercritical CO2 flooding

Physics of Fluids, Journal Year: 2024, Volume and Issue: 36(12)

Published: Dec. 1, 2024

Research on the formation and distribution characteristics of remaining oil has primarily focused individual scales, with studies at both pore scale core often lacking effective integration, particularly under supercritical conditions. In this study, a high-temperature high-pressure microfluidic experimental system (temperature: 75 °C, pressure: 22 MPa) micro-computed tomography (CT) scanning technology were employed to systematically investigate mechanisms five different types after CO2 injection. The results indicate that injection, mainly appears in columnar droplet patterns, predominantly distributed pores ranging from 4 13 μm, is significantly influenced by Marangoni effect Jamin effect. Additionally, scale, recovery increased approximately 8.7% high flow rates (0.5 ml/min) compared low (0.1 ml/min); contrast, decreased 15.9%. This contrasting behavior can be attributed non-uniformity caused fingering effect, which leads uneven fluid within porous media. comparison between provides new insights into understanding patterns oil.

Language: Английский