Petrophysical Characterization of 3-D Printed Rock and Its Substitution in the Validation Experiment

Abstract

Many cutting-edge technologies have the potential to become the game-changer of the oil and gas industry in the near future. 3D printing, known as rapid prototyping, is the active tool in multiple disciplines, which need to be applied further in the petroleum geology and petroleum engineering. It has been attempted to replace the natural rocks which are typically expensive and hardly accessible. However, the fundamental characteristics of 3D printed rocks have not been fully understood, and the application just stays the preliminary stage. In this study, samples from synthetic gypsum rocks, which are produced by 3D printing technology, were scanned by X-ray micro-tomography with the resolution of 8 μm. Petrophysical properties of pore structure, including porosity, pore size distribution, pore surface area, pore connectivity, and hydraulic radius are measured and analyzed. Using the processing software, permeability was also simulated based on the reconstructed pore model. The results from the micro-CT show that the porosity of this 3D printed rock sample is 20.84%, which is less than the result of Helium Porosimetry, 28.86%. The difference is because of the resolution effect of micro-CT that it missed the micro- and nano-scale pores which is smaller than 8μm. With the known petrophysical properties of 3D printed rocks, we employed these samples to substitute the drilling rock cores in the validation experiment. The ultrasonic velocity measurements under different source frequency and confining pressure were performed in the laboratory environment. The results of the validation experiments are consistent with the theoretical prediction, which proves that 3D printed rocks can be the proper methods to facilitate the efficiency of laboratory experiments.

AAPG Datapages/Search and Discovery Article #90323 ©2018 AAPG Annual Convention and Exhibition, Salt Lake City, Utah, May 20-23, 2018