(57c) Rock-Based Micromodel and CFD Studies of Nanomaterial Transport for Reservoir Applications

Both physical micromodels and pore-scale computational models have a long history of providing insight into pore-scale transport mechanism relevant to the oil and gas industry.  Additionally, during the past decade microcomputed tomography (microCT) has become widely used for pore-scale analysis and modeling because it can provide nondestructive images of the interior geometry, composition, and fluid distribution in porous rocks. In this work, we integrate microCT with micromodel and pore-scale modeling technology to help understand the transport of micro- and nano-particle transport in rock samples.

A new technique has been developed in which a 3D microCT image is used to create a pattern for fabrication of 2.5D micromodels. The terminology “2.5D” means that the micromodel has a varying floor elevation (in addition to the heterogeneous areal pattern). However, it does not have intertwined channels that pass over or under one another as in a truly 3D structure. The basis of the micromodel pattern is a 3D microCT image of an outcrop sandstone. To construct the 2.5D pattern, an optimization procedure was used in which a series of computer simulations were performed to match both the pore structure and single-phase fluid mechanics in the 2.5D micromodel to the 3D rock as closely as possible.

Micromodel experiments as well as 3D computer simulations (on the original rock) are being performed to better understand the transport and retention of microparticles and nanoparticles. Single-particle computer simulations are used to help understand the effect of the pore geometry on particle trajectories, locations of retention, and the forces on the particles. Micromodel experiments can be performed with many particles and include physics that cannot yet be incorporated into the computational modeling. They provide insight into factors that are contributing to transport versus retention of the particles.