scholarly journals Migration of Gas in Water Saturated Clays by Coupled Hydraulic-Mechanical Model

Geofluids ◽  
2018 ◽  
Vol 2018 ◽  
pp. 1-25 ◽  
Author(s):  
Aliaksei Pazdniakou ◽  
Magdalena Dymitrowska
Keyword(s):  
Mechanical Model ◽  
Fluid Transport ◽  
Two Phase Flow ◽  
Ion Beam ◽  
Damage Model ◽  
Phase Flow ◽  
Two Phase ◽  
Local Conditions ◽  
Small Pore ◽  
Water Saturated

Understanding the gas migration in highly water saturated sedimentary rock formations is of great importance for safety of radioactive waste repositories which may use these host rocks as barrier. Recent experiments on drainage in argillite samples have demonstrated that they cannot be represented in terms of standard two-phase flow Darcy model. It has been suggested that gas flows along highly localized dilatant pathways. Due to very small pore size and the opacity of the material, it is not possible to observe this two-phase flow directly. In order to better understand the gas transport, a numerical coupled hydraulic-mechanical model at the pore scale is proposed. The model is formulated in terms of Smoothed Particle Hydrodynamics (SPH) and is applied to simulate drainage within a sample reconstructed from the Focused Ion Beam (FIB) images of Callovo-Oxfordian claystone. A damage model is incorporated to take into account the degradation of elastic solid properties due to local conditions, which may lead to formation of new pathways and thus to modifications of fluid transport. The influence of the damage model as well as the possible importance of rigid inclusions is demonstrated and discussed.

scholarly journals A fully coupled thermal-hydraulic-mechanical model with two-phase flow for coalbed methane extraction

2016 ◽  
Vol 33 ◽  
pp. 324-336 ◽  
Author(s):  
Sheng Li ◽  
Chaojun Fan ◽  
Jun Han ◽  
Mingkun Luo ◽  
Zhenhua Yang ◽  
...  
Keyword(s):  
Mechanical Model ◽  
Coalbed Methane ◽  
Two Phase Flow ◽  
Phase Flow ◽  
Two Phase ◽  
Methane Extraction ◽  
Fully Coupled

scholarly journals Thermoplastic Micromodel Investigation of Two-Phase Flows in a Fractured Porous Medium

2017 ◽  
Author(s):  
Shao-Yiu Hsu ◽  
Zhong-Yao Zhang ◽  
Chia-Wen Tsao
Keyword(s):  
Porous Media ◽  
Two Phase Flow ◽  
Fractured Rock ◽  
Flow Behavior ◽  
Phase Flow ◽  
Large Radius ◽  
Two Phase ◽  
Visualization System ◽  
Optical Visualization ◽  
Small Pore

In the past few years, micromodels have become a useful tool for visualizing flow phenomena in porous media with pore structures, e.g., the multifluid dynamics in soils or rocks with fractures in natural geomaterials. Micromodels fabricated using glass or silicon substrates incur high material cost; in particular, the microfabrication-facility cost for making a glass or silicon-based micromold is usually high. This may be an obstacle for researchers investigating the two-phase-flow behavior of porous media. A rigid thermoplastic material is a preferable polymer material for microfluidic models because of its high resistance to infiltration and deformation. In this study, cyclic olefin copolymer (COC) was selected as the substrate for the micromodel because of its excellent chemical, optical, and mechanical properties. A delicate micromodel with a complex pore geometry that represents a two-dimensional (2D) cross-section profile of a fractured rock in a natural oil or groundwater reservoir was developed for two-phase-flow experiments. Using an optical visualization system, we visualized the flow behavior in the micromodel during the processes of imbibition and drainage. The results show that the flow resistance in the main channel (fracture) with a large radius was higher than that in the surrounding area with small pore channels when the injection or extraction rates were low. When we increased the flow rates, the extraction efficiency of the water and oil in the mainstream channel (fracture) did not increase monotonically because of the complex two-phase-flow dynamics. These findings provide a new mechanism of residual trapping in porous media.

scholarly journals Mechanism of the Gas-Liquid Two-Phase Chaotic Flow in Single Fracture

Geofluids ◽  
2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Dong Yang ◽  
Zhiqin Kang ◽  
Yangsheng Zhao
Keyword(s):  
Numerical Simulation ◽  
Fluid Transport ◽  
Two Phase Flow ◽  
Underlying Mechanism ◽  
Single Fracture ◽  
Phase Flow ◽  
Stochastic Variation ◽  
Two Phase ◽  
Remarkable Change ◽  
Gas Liquid Flow

The seepage of gas-liquid two-phase flow in fracture is a commonly found phenomenon in nature. To reveal the underlying mechanism and the critical condition of the chaos occurrence, a stochastic gas-liquid two-phase flow seepage model is established, and then investigated through a numerical simulation and a horizontal Hele-Shaw experiment. The numerical simulation and laboratory experiment results show that the seepage chaos of gas-liquid two-phase flow takes place when the relative saturation is in the range of gas relative saturation 44%-70%, and the occurrence probability can be expressed in polynomials. The chaos probability exceeds 80% when the relative saturation of gas is 47%-65%, and the chaos probability is 100% when the relative gas saturation is 57%-60%. It is found that the stochastic variation of gas connection cluster and the compressibility of gas lead to a remarkable change of pressure gradient of the gas-liquid flow both in magnitude and direction. Therefore, the turbulent flow is formed, the kinetic energy of fluid transport decreases gradually, and the flow is stopped at last.

scholarly journals Influence of Non-newtonian Properties of Liquid in Microchannels on Pressure Drop and Bubble Length

2021 ◽  
Author(s):  
Gang Yang ◽  
Kai Feng ◽  
Jia-Pei Li ◽  
Yu-Hang Gao ◽  
Hui-Chen Zhang
Keyword(s):  
Pressure Drop ◽  
Single Phase ◽  
Fluid Transport ◽  
Two Phase Flow ◽  
Phase Flow ◽  
Flow Focusing ◽  
Single Phase Flow ◽  
Two Phase ◽  
Bubble Length ◽  
Transport Device

Abstract Pressure drop and bubble morphology are essential characteristics of microfluidic system design and process control. In this paper, a new type of microfluidic chip was designed and produced, including a flow-focusing device and a fluid transport device to simulate bubble generation and fluid transport in practical applications. Nitrogen and sodium carboxymethyl cellulose solutions of different concentrations were used as the gas and liquid phases. Single-phase flow and two-phase flow experiments were designed according to the commonly used flow conditions in the microchannel. By changing the flow rates of liquid and gas, the pressure drop in the fluid transport device of the two fluid states, the length of the bubble generated in the flow-focusing device, and the length of the bubble after passing through the transport device were measured, respectively. The influence of non-Newtonian characteristics of the liquid on pressure drop and the length of the generated bubbles were analyzed. The results show that the non-Newtonian characteristics of fluid have a significant effect on the pressure drop of single-phase flow and two-phase flow. Within a specific flow velocity range, the bubble length can be predicted according to the dimensionless number of the liquid. The pressure drop increases the bubble length to varying degrees.

Optic Imaging of Two-Phase-Flow Behavior in 1D Nanoscale Channels

SPE Journal ◽  
2014 ◽  
Vol 19 (05) ◽  
pp. 793-802 ◽  
Author(s):  
Qihua Wu ◽  
Baojun Bai ◽  
Yinfa Ma ◽  
Jeong Tae Ok ◽  
Keith B. Neeves ◽  
...  
Keyword(s):  
Fluid Flow ◽  
Shale Gas ◽  
Two Phase Flow ◽  
Water Saturation ◽  
Flow Behavior ◽  
Gas Production ◽  
Production Optimization ◽  
Phase Flow ◽  
Two Phase ◽  
Small Pore

Summary Gas in tight sand and shale exists in underground reservoirs with microdarcy (µd) or even nanodarcy (nd) permeability ranges; these reservoirs are characterized by small pore throats and crack-like interconnections between pores. The size of the pore throats in shale may differ from the size of the saturating-fluid molecules by only slightly more than one order of magnitude. The physics of fluid flow in these rocks, with measured permeability in the nanodarcy range, is poorly understood. Knowing the fluid-flow behavior in the nanorange channels is of major importance for stimulation design, gas-production optimization, and calculations of the relative permeability of gas in tight shale-gas systems. In this work, a laboratory-on-chip approach for direct visualization of the fluid-flow behavior in nanochannels was developed with an advanced epi-fluorescence microscopy method combined with a nanofluidic chip. Displacements of two-phase flow in 100-nm-depth slit-like channels were reported. Specifically, the two-phase gas-slip effect was investigated. Under experimental conditions, the gas-slippage factor increased as the water saturation increased. The two-phase flow mechanism in 1D nanoscale slit-like channels was proposed and proved by the flow-pattern images. The results are crucial for permeability measurement and understanding fluid-flow behavior for unconventional shale-gas systems with nanoscale pores.

Sign in / Sign up

Export Citation Format

Share Document