CO2 huff-n-puff experimentation and numerical simulation for 3D printed rock samples

Abstract

3D printed rock samples advance the experimental research of fluid flow physics in the petroleum industry. 3D printed replicas can be flexibly tailored to different experimental setups, in addition to the low cost of creation with uniform materials. The conducted experiments, on 3D printed samples, have less geometrical uncertainties, which is related to the accurately described structure of the pore network. The difficulties of describing fluid-rock interaction are diminished because of the compositional uniformity of the 3D-printing material. Therefore, 3D printed replicas were used, in this paper, to demonstrate the CO2 effects on oil recovery through a huff and puff experiment. The CT scan of a Berea core sample was reconstructed using image processing to prepare a 3D printable object. The two samples, i.e., the 3D printed gypsum replica and its original Berea core sample, were inserted simultaneously in a newly designed experimental setup to conduct the huff and puff experiment under the same conditions. The oil recovery was reported at three different CO2 injection pressures and temperatures. After running the experiment, the synthetic core sample was broken laterally and longitudinally to examine the CO2 action in the sample visually. As a pioneer study, the CO2 effect on a 3D-printed core sample was pictured, which can be used to explain the physics of CO2 diffusion in porous media. Finally, a supporting simulation model was created based on the CT scan to simulate the experiment. The simulation results matched the recovery results for the 3D printed replica and generated oil composition crosssections similar to the pictured ones.