Microfluidics experimental study in porous media applied for nanosilica/alkaline flooding

The effective development of low permeability heavy oil reservoirs is crucial for tapping into unconventional resources. High-pressure CO 2 flooding offers numerous benefits, including reducing crude oil viscosity, enhancing oil fluidity, and decreasing interfacial tension, leading to improved heavy oil production. Additionally, CO 2 can be sequestered in the formation, contributing to carbon emission reduction. However, analyzing the migration and storage effects of CO 2 in low permeability heavy oil reservoirs is challenging. In this study, high-pressure and hightemperature (50 MPa,100 °C) microfluidic experiments were designed and carried out, and the CO 2 flooding characteristics and storage efficiency were studied. The distribution of the remaining oil and mechanisms of CO 2 sequestration under various displacement speeds and injection pressures were analyzed. The results demonstrated that CO 2 flooding achieved significantly higher recovery rates compared to high-pressure water flooding, with increments of 13.89, 21.53, and 23.09% at oil displacement pressures of 30, 40, and 50 MPa, respectively. The CO 2 burial efficiency also showed substantial improvements, reaching 23.55, 34.01, and 37.13% under the corresponding conditions. Furthermore, a higher porosity facilitated CO 2 migration, providing more space and migration channels for CO 2 flow. By examining CO 2 −oil interactions, the study elucidated CO 2 migration patterns and burial efficiency under different displacement modes.

Section: Discussionmentioning

confidence: 99%

Mechanisms of Fluid Migration and CO₂ Storage in Low Permeability Heavy Oil Reservoirs Using High-Pressure Microfluidic CO₂ Flooding Experiment

Li,

Zheng,

Shi

et al. 2024

“…They mentioned that with a rise in nanoparticle concentration, the air−liquid contact angle on a smooth surface changed from oil-wet to water-wet. 9 T h i s c o n t e n t i s The studies conducted so far on the impact of a low-salinity nanofluid on wettability modification have focused on smooth surfaces. This is because nanoparticles tend to create a wedge film on flat surfaces, which enhances the disjoining pressure and alters the wettability of the surface.…”

Section: Introductionmentioning

confidence: 99%

“…An anionic surfactant (AOT) improved the effect of silica nanoparticles (SiNPs) under low-salinity conditions and altered the wettability of the Berea sandstone core from oil-wet to water-wet at an appropriate cation-to-sulfate-ion ratio: the consequence of SiNPs on the alkali solution. They mentioned that with a rise in nanoparticle concentration, the air–liquid contact angle on a smooth surface changed from oil-wet to water-wet …”

Section: Introductionmentioning

confidence: 99%

Silica Nanofluids in Low Salinity Water for Wettability Alteration of the Mineral Surface and the Effect of Surface Roughness

Seetharaman,

Sangwai

2024

Surface roughness plays a crucial role in oil recovery operation. Wenzel's equation relates the contact angle of a liquid droplet on a rough surface to its intrinsic contact angle and surface roughness. Herein, we report the impact of surface roughness on the wettability of rough quartz surfaces using silica nanofluid in low-salinity (low-sal) water under different temperature and pressure conditions. We employed atomic microscopy to analyze the roughness of a quartz surface that shows varying degrees of roughness. The results of nanofluid stability reveal that one of the key factors enhancing the colloidal stability of silica nanoparticles is the electrolyte's pH. Increasing the surface roughness of the quartz substrate from 34.6 to 415 nm decreased the contact angle of crude oil from 63 to 30°. Furthermore, a decrease in contact angle with an increase in temperature is prominent for the nanofluid on highly rough surfaces. Likewise, a slight increase in surface roughness exaggerates the effect of pressure on the contact angle of the quartz surface. Scanning electron microscopy and energy-dispersive X-ray analyses confirm the dendritic structure of the low-sal-silica nanofluid on the rough surface. Our study strengthens the hypothesis that surface roughness together with surface chemistry is the key factor in determining quartz surface wettability.

“…Flow through a porous medium has numerous applications in enhanced oil recovery, − CO 2 sequestration, − subsurface hydrology, geothermal energy production, and gas production from hydrate-bearing formations. , Therefore, it is essential to understand the displacement mechanism and pore-scale phenomena during the two-phase flow in a porous medium. A few experimental studies have investigated the effect of various chemicals and nanofluids on the pore-scale flow dynamics and displacement processes. − It is difficult, expensive, and time consuming to experimentally investigate the flow dynamics on the pore scale. However, it is feasible to investigate the pore-scale processes using numerical simulations.…”

Section: Introductionmentioning

confidence: 99%

Numerical Simulation of Pore-Scale Fluid Mobilization during Immiscible Displacement

Sharma,

Singh,

Tiwari

et al. 2023

A significant amount of oil remains trapped in the deal-ends of a porous network during a water flooding process in an oil reservoir. A deep insight into the immiscible displacement mechanism, effect of rock and fluid properties, and dead-end geometry on the trapped oil recovery from the complex pores is required. We present numerical simulations of immiscible two-phase flow at the pore scale to understand the displacement mechanism in the complex pores (dead-ends and contraction−expansion) and parameters affecting the oil recovery. The effects of displacing phase injection velocity, viscosity ratio, wettability alteration, viscosity of trapped oil, and geometric ratio on the trapped oil recovery have been investigated. The results show that decreasing the contact angle has a marginal effect on the recovery of the trapped fluid until a critical contact angle is reached. It is observed that at smaller contact angles (water-wet condition) water displaces the oil along the dead-end walls. The simulations show that when the oil/water interface reaches the bottom of the dead-end before it reaches the rupture point at the pore throat junction, there is complete displacement. Increasing the displacing phase injection velocity significantly increases the oil recovery from dead-end pores. On the other hand, decreasing the injection velocity results in improved oil recovery from the contraction-expansion pores. The increase in the viscosity ratio (displacing phase to the displaced phase) has little impact on the oil recovery from both types of complex pores. Furthermore, it has been observed that with an increase in the dead-end depth oil recovery decreases, and the critical contact angle required for complete displacement is much lower. This study can be useful to develop the right strategies to recover trapped oil from the complex pores.