Increasing Density of 3D-Printed Sandstone through Compaction

Abstract

The geomechanical and transport properties of rocks are of great importance to geoscience and engineering, as these properties provide responses to external stresses and flow regimes in the subsurface. Typically, experiments conducted on cores from reservoir formations have a degree of uncertainty, due to the heterogeneous characteristics of rock samples. To combat this uncertainty, binder-jet additive manufacturing (3D printing) is an emerging technology to characterize natural porous media in a repeatable fashion. In this study, the 3D printing sandstone analogue involved sand powder and organic binder to mimic silica grains and cement in natural sandstone. The use of compaction rollers and the adjustment of printing parameters allowed one to test how the porosity and strength of 3D-printed samples can replicate the transport and geomechanical properties of natural sandstone. The densities of samples were increased by ~15% and compressive strength by ~65% with the use of the larger roller. This is a promising alternative to experimental testing to calibrate numerical models in geoscience and engineering. The significance of this approach is to allow for customizable porosity, permeability, and strength in rock samples, while preserving scarce natural rock samples.

An In-depth Analysis of Strength and Stiffness Variability in 3D-Printed Sandstones: Implications for Geomechanics

“…The failure mode for most samples was characterized by two phenomena: the formation of a coneshaped structure at one end of the specimen and axial splitting from the cone's apex. This behavior aligns with the findings reported in previous studies [5][6][7][8][9]16].…”

“…This process is repeated layer by layer until the 3D volume is complete. All samples were subjected to a set binder saturation of 20%, given that this factor considerably impacts the strength properties of the printed sandstones [6,16]. Binder saturation refers to the volume of binder occupying the pore space.…”

“…Hodder et al [16] explored the densification of 3D-printed sandstones. By adjusting printing parameters and using compaction rollers, the authors increased the samples' density by approximately 15% and the UCS by around 65%.…”

Characteristics and mechanism of time on sand powder 3D printing rock analogue: a new method for fractured rock mechanics

“…Notably, after approximately 30 days of placement, the mass variation for the specimens was merely 1 g, underscoring their relative stability under room temperature conditions without necessitating any subsequent treatments. Moreover, the mass and density of the printed specimens in this study closely approximated the outcomes documented by Hodder et al (2022). 3.2 Influence of placement time on mechanical properties of specimens…”

“…The mechanical behavior and failure patterns of sand powder 3D printed rock-like specimens bear a striking resemblance to the mechanical attributes and failure modes observed in natural rocks (Kong et al et al 2019;Hodder et al 2022). Thus, this section primarily delves into the distinctions in failure modes across specimens with varying placement durations.…”