# Assessing the Influence of Confining Pressure on the Consolidation of Granular Bulk Models Using an Integrated Sensor System

## TL;DR

A new experimental setup shows that confining pressure helps stabilize granular models used to study porous media flow, leading to more reliable data.

## Contribution

A novel apparatus with integrated sensors is introduced to study consolidation in granular bulk models under confining pressure.

## Key findings

- Unconfined models show nonlinear flow-pressure relationships and unstable electrical resistance.
- Confining pressure leads to uniform consolidation and reduced hysteresis in granular models.
- Effective confinement is critical for accurate representation of porous media behavior.

## Abstract

Large-scale bulk models offer a promising approach for the experimental investigation of flow in porous media. However, conventional configurations frequently lack adequate confinement systems, resulting in model instability under dynamic flow conditions. This paper introduces a novel experimental apparatus designed for large-scale porous media flooding studies. The porous medium is represented by a tubular granular bulk model measuring one meter in length and 95 mm in diameter. An integrated array of distributed pressure, temperature, and electrical resistance sensors allows for the acquisition of a longitudinal pressure profile, the evaluation of the model’s consolidation state, and the assessment of its stress sensitivity. Comparative studies of filtration processes are presented for a granular bulk model under both confined and unconfined conditions. The results indicate that in the absence of confinement, the model exhibits high sensitivity to pressure differentials, manifesting as a nonlinear relationship between flow rate and pressure drop alongside significant fluctuations in electrical resistance. Conversely, cyclic loading under confining pressure promotes uniform and stable consolidation of the model, thereby minimizing hysteresis and particle displacement. These findings underscore that effective confinement is critical for ensuring the representativeness of data derived from large-scale bulk models of unconsolidated porous media.