TESTING THE ACCURACY OF 3D PRINTED RESERVOIR POROSITY MODELS

3D printing is a new technology, that has numerous research applications in engineering, design, medicine, and even geology. This research uses mercury intrusion porosimetry to evaluate how well 3D printers can reproduce models of reservoir rock porosity. These models are built in computer-aided design software (for example, SolidWorks). They range in complexity from simple cylinders with a single through-going pore to more complex pore networks. Mercury porosimetry has provided measurements of porosity, pore throat size distribution and surface area on 3D printed porosity models that have been compared with similar properties calculated on the digital models. Our first experiments involved comparing digital and experimental measurements of porosity, surface area, and pore throat size distribution. On average, the 3D printed pore throats were around 150 microns thinner than designed. Porosity and surface area from mercury injection were higher than calculated from the digital model. Pore throat size distribution was bimodal. The designed single pore throat (800-1000 microns) was represented by a flat-topped peak spanning from 1mm to 100 microns. Sub-micron size pores were identified as well, even though they weren’t designed. We suggest that these are artifacts of the 3D printing process. Understanding the properties of these simple models will allow a better understanding of 1) mercury porosimetry and 2) how more complex models can be 3-D printed.