An insight into the formation of liquid bridge and its role on fracture capillary pressure during gravity drainage in fractured porous media

Abstract

The formation of liquid bridges can maintain capillary continuity between matrix blocks during gas/oil gravity drainage in fractured reservoirs. A travelling oil drop draining into a fracture either forms a liquid bridge or breaks into detached drops. However, the different characteristics of a travelling drop during its elongation and required conditions for transformation into a liquid bridge are not well described in the published literature. In this work, a onedimensional model based on slender-drop theory is employed that holds gravity, viscosity, and surface tension forces but ignores inertia. This model, together with Young-Laplace equation, gives the fracture capillary pressure.Then, the effect of liquid influx rate, viscosity, surface tension, density difference, contact angle, and contact radius on the shape, critical (or maximum) volume, and length of travelling liquid drops is analyzed and compared with the results in the absence of flow (ie, pendant drops). Critical length is shown to be an increasing function of both liquid viscosity and the influx rate, but the effect of surface tension and density is somewhat case dependent. Furthermore, it is found that if fracture aperture is equal to or less than the critical length of a drop, the formed liquid bridge would be stable. Also, fracture capillary pressure is shown to be remarkable in thin fractures (apertures of less than 50 μm) with embedded liquid bridge. On the other hand, the suspended oil drops, even when reaching critical length, cannot provide considerable capillary pressure.

Experimental methods in chemical engineering: Pressure

“…Eng. were "Liquid film thickness of two-phase slug flows in capillary microchannels: A review paper" (magenta cluster), [42] "An insight into the formation of liquid bridge and its role on fracture capillary pressure during gravity drainage in fractured porous media" (yellow cluster), [43] , and "Computational fluid dynamic simulations of regular bubble patterns in pulsed fluidized beds using a two-fluid model" (magenta cluster). [44] Applications of pressure measurement vary from routine set-point monitoring to a more complex analysis of fluctuation characteristics for system control (blue cluster).…”

“…'Guidelines for Performing Lignin-First Biorefining' [43] (65 citations, red cluster), 'Anti-Freezing, Resilient and Tough Hydrogels for Sensitive and Large-Range Strain and Pressure Sensors', [44] (52 citations), and 'An Overview of Inorganic Particulate Matter Emission from Coal/ Biomass/MSW Combustion: Sampling and Measurement, Formation, Distribution, Inorganic Composition and Influencing Factors', [45] (51 citations, red cluster). The three top cited articles in The Canadian Journal of Chemical Engineering were 'Liquid Film Thickness of Two-Phase Slug Flows in Capillary Microchannels: A Review Paper' (magenta cluster), [46] 'An Insight Into the Formation of Liquid Bridge and Its Role on Fracture Capillary Pressure During Gravity Drainage in Fractured Porous Media' (yellow cluster), [47] and 'Computational Fluid Dynamic Simulations of Regular Bubble Patterns in Pulsed Fluidized Beds Using a Two-Fluid Model' (magenta cluster). [48] Applications of pressure measurement vary from routine set-point monitoring to a more complex analysis of fluctuation characteristics for system control (blue cluster).…”

Performance Quantification of Enhanced Oil Recovery Methods in Fractured Reservoirs

“…In other words, both capillary and gravitational forces play an essential role in the overall recovery. Moreover, the dominance of either gravity or capillary forces can determine the magnitude and direction of flow into the matrix block during different EOR methods [5,6,11,16].…”

“…Gravitational and capillary forces have the leading roles in capillary continuity and reinfiltration processes. In the case of the stack of matrix blocks, capillary continuity and reinfiltration phenomena occur due to block-to-block interactions, which might lead to oil recovery reduction [5,6]. In the reinfiltration process, drained oil from upper blocks can be reimbibing into lower blocks through the liquid bridges and film flow across contact points between vertical blocks.…”

“…Re-infiltration is affected by capillary and gravity forces. Conversely, capillary continuity in the vertical direction between matrix blocks can improve the oil recovery [5,6].…”