Dr. TieJun Zhang’s team at Khalifa University has developed a new way to 3D print reservoir rock replicas that have complex porous structures and mimic a carbonate rock’s natural mineralogy. The rocks, micro 3D printed using PµSL technology from BMF (Boston Micro Fabrication), are transparent, and allow researchers to image precisely how fluid flows through the ultra-tiny pores of rock. This information could help develop more effective strategies for hydrocarbon and geothermal energy extraction, carbon sequestration, and even ice mining and water extraction from the ground during planetary exploration.
The 3D printed rock created at Khalifa University can be used as a sort of ‘rock-on-a-chip’ to analyze how various fluids move through the pores, to gain key insights into energy extraction of more hydrocarbons from the oil fields in a more sustainable and cost-effective way. Being readily tailored to test, observe and analyze fluidics, their technology also makes microfluidic technology more accessible to researchers in various fields and accelerates innovation in biological, soft robotics, aerospace, and other emerging applications.
The transparent “rock” fabrication approach includes three main steps: 3D micromodel printing using particle-free resin (HDDA); (ii) Calcite nanoparticles (CalNPs) seeding along the inner surfaces of as-printed micromodel; and (iii) In-situ growth of calcite nano/micro montmorillonite crystals inside the micromodel. In micromodel printing, the use of particle-free resin in the printing step creates sharply defined features by avoiding lighting scattering in the photopolymerization process. The second step includes coating a seed layer of nanoparticles (e.g., calcite nanoparticles (CalNPs), or other suitable nanoparticles) to fertilize the subsequent uniform growth of mineral nano/microcrystals.
The BMF micro 3D printers were used to build 3D porous rock skeletons, mimicking the pore-throat structures inside a natural reservoir rock suited for energy extraction. The layer-by-layer printing process is based on a stack of micro-CT images from real rock. Boston Micro Fabrication (BMF) 3D printers can create a feature size with up to 2 µm resolution, comparable with the pore sizes of oil-bearing rocks for the majority of the reservoirs worldwide. Khalifa University Graduate Fellow Hongxia Li confirmed that BMF PµSL technology was ideal for creating the reservoir rock micromodel fabrication “because of its high printing resolution.”