Red Noise in Steady‐State Multiphase Flow in Porous Media

Spurin, Catherine; Rücker, Maja; Moura, Marcel; Bultreys, Tom; Garfi, Gaetano; Berg, Steffen; Blunt, Martin J.; Krevor, Samuel

doi:10.1029/2022wr031947

Cited by 12 publications

(18 citation statements)

References 63 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…However, in experiment H, it matched only the f w = 0.9 case, which had an intermittency volume of 2.6%. For f w = 0.7 and 0.5, with intermittency volumes around 1.5%, the power associated to the longer timescales was significantly below red noise scaling, and thus differed from mm-scale observations by Spurin et al (2022). Since lower frequencies relate to larger sized fluid redistribution events, this may be further evidence for the need to study multiphase dynamics at the core-scale rather than in smaller samples.…”

Section: Representative Elementary Volumementioning

confidence: 85%

“…Further research with more data points is needed to investigate the results presented here. (2) Spurin et al (2022) asserted that the longest time-scales in this spectrum correspond to repetitive filling of the largest intermittent pores. They showed that the gas connectivity changed for intermittency with a time scale of 8-10 minutes as gas ganglia repeatedly connected and disconnected, while the intermittent gas occupancy with shorter time scales (i.e.…”

Section: Representative Elementary Volumementioning

confidence: 96%

“…These samples are smaller than the typical representative elementary volume (REV) for multiphase flow, making the upscaling from the pore-scale to the core-scale more difficult (Jackson et al, 2020, Zahasky et al, 2020. It has been hypothesized that intermittency does not average out at the REV-scale based on the analysis of fluctuations in the pressure drop over the sample (Rücker et al, 2021;Spurin et al, 2022), yet pore-scale variations in the fluid distribution have not been observed and characterized directly in REV-scale samples.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Pore-scale imaging of multiphase flow fluctuations in core-scale samples

Wang

Spurin

Bultreys

2023

Preprint

View full text Add to dashboard Cite

Representative elementary volumes (REVs) are an important concept in studying subsurface multiphase flow at the continuum scale. However, fluctuations in multiphase flow are currently not represented in continuum scale models, and their impact at the REV-scale is unknown. Previous pore-scale imaging studies on these fluctuations were limited to small samples with mm-scale diameters and volumes on the order of ~ 0.5 cm3. Here, we image steady-state co-injection experiments on a one-inch diameter core plug sample, with nearly two orders of magnitude larger volume (21 cm3), while maintaining a pore-scale resolution with X-ray micro-computed tomography. This was done for three total flow rates in a series of drainage fractional flow steps. Our observations differ markedly from those reported for mm-scale samples in two ways: the macroscopic fluid distribution was less ramified at low capillary numbers (Ca) of 10-7; and the volume fraction of intermittency initially increased with increasing Ca (similar to mm-scale observations), but then decreased at Ca of 10-7. Our results suggest that viscous forces may play a role in the cm-scale fluid distribution, even at such low Ca, dampening intermittent pathway flow. A REV study of the fluid saturation showed that this may be missed in smaller-scale samples. Pressure drop measurements suggest that the observed pore-scale fluctuations resulted in non-Darcy like upscaled behavior. Overall, we show the importance of large field-of-view high-resolution imaging to bridge the gap between pore- and continuum-scale multiphase flow studies, in particular of pore-scale fluctuations.

show abstract

Section: Representative Elementary Volumementioning

confidence: 85%

Section: Representative Elementary Volumementioning

confidence: 96%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Pore-scale imaging of multiphase flow fluctuations in core-scale samples

Wang

Spurin

Bultreys

2023

Preprint

View full text Add to dashboard Cite

show abstract

“…In recent work exploring fluctuations in pressure data, red noise was observed [66]. This observation implies a cascade of timescales, with the longer timescales correlating to larger events.…”

Section: Sampling Intervals and Their Impact On Dmdmentioning

confidence: 87%

Dynamic Mode Decomposition for Analyzing Dynamics in Multi-phase Flow in Porous Media

Spurin¹,

Berg²,

Armstrong³

et al. 2022

Preprint

View full text Add to dashboard Cite

For multi-phase flow through multi-scale heterogeneous porous media, such as the pore space of rocks, the interaction between multiple immiscible fluids and an intricate network of pores, creates a wide range of dynamic flow phenomena. At larger scales i.e. scales relevant for practical applications such as carbon sequestration, this interplay of dynamic phenomena is often referred to as "complexity". However, it is important to describe the persistent features of the flow in an adequate manner, to represent the "complexity" of the system. Dynamic mode decomposition (DMD) is a dimensionality reduction algorithm that computes a set of modes associated with fixed oscillatory behaviours. In this work, data is extracted from dynamic two-phase flow experiments and analyzed with DMD. We show that DMD can reproduce the data. Furthermore, not all dynamic modes are required to reproduce key dynamic features; this highlights the important spatial and temporal scales for flow. We show that dynamic mode decomposition was able to identify localized regions important to flow. Overall, DMD is proven as a useful diagnostic tool for complex 4D flow dynamics for multi-phase flow.

show abstract

“…Fractional flow experiments typically aim to achieve a "steady-state" at each fractional flow step, which means both the saturation and pressure drop become time-independent. However, clear pressure fluctuations can be found in many fractional flow experiments (Lin et al, 2018;Menke et al, 2022;Spurin et al, 2022;Zou et al, 2018), and also The experiments H 0.5 , M 0.9 and L 0.9 are selected because of the similar brine saturation in these three cases.…”

Section: Differential Pressure Measurements and Darcy's Lawmentioning

confidence: 99%

Pore‐Scale Imaging of Multiphase Flow Fluctuations in Continuum‐Scale Samples

Wang

Spurin

Bultreys

2023

Water Resources Research

Self Cite

View full text Add to dashboard Cite

Understanding multiphase flow in geological porous materials is central to the safe storage of CO 2 underground (Jeddizahed & Rostami, 2016;Streit & Hillis, 2004) and successful containment of contaminants in the subsurface (McCarthy, 2018). Complex flow dynamics arise from fluid-fluid and fluid-solid interactions over multiple length and time scales (Bultreys et al., 2016;Krevor et al., 2015;Pentland et al., 2011). The underlying pore-scale physics are considered to be mainly controlled by the competition between capillary forces and viscous forces (Chen et al., 2018;Panda et al., 2019;Spurin et al., 2019b). The ratio of these two forces expressed by means of the capillary number (Ca = μv/σ) is commonly used to differentiate between flow regimes. In the majority of subsurface porous medium applications, the fluid flow is very slow, resulting in capillary numbers <10 −7 (Bultreys, 2016).At the Darcy scale, multiphase flow in porous media is described using averaged properties such as capillary pressure and relative permeability (Lin et al., 2018;Parker, 1989;Zahasky et al., 2020), ignoring fluctuations at the pore scale. However, recent observations at the pore-scale have shown that complex interface dynamics occur even during so-called "steady-state" flow, where the average fluid saturation of the system remains constant (Reynolds et al., 2017;Zou et al., 2018). For example, fluid phases can rearrange and periodically disconnect and reconnect in a process called intermittent pathway flow, or intermittency (Gao et al., 2019;Reynolds et al., 2017;Spurin et al., 2019a). This influences the energy dissipation in the system and, therefore, impacts the averaged behavior at larger scales (Rücker et al., 2021). Thus, the assumption of static interfaces in quasi-static models or continuum frameworks may not be accurate. These phenomena occur even in capillary dominated flow regimes that are commonly assumed to be quasi-static, especially when the viscosity ratio (i.e., ratio of nonwetting phase viscosity to wetting phase viscosity) of the two fluids is very low, as for liquid-gas flows. Previous studies, in small mm-scale samples found intermittent pathway flow was most common, and important to fluid connectivity, at capillary numbers around 10 −8 -10 −6 , with the percentage of intermittently-occupied pores increasing with capillary number, and heterogeneity of the pore space (Spurin et al., 2019a(Spurin et al., , 2019b.

show abstract

Red Noise in Steady‐State Multiphase Flow in Porous Media

Cited by 12 publications

References 63 publications

Pore-scale imaging of multiphase flow fluctuations in core-scale samples

Pore-scale imaging of multiphase flow fluctuations in core-scale samples

Dynamic Mode Decomposition for Analyzing Dynamics in Multi-phase Flow in Porous Media

Pore‐Scale Imaging of Multiphase Flow Fluctuations in Continuum‐Scale Samples

Contact Info

Product

Resources

About