Analysis of subterranean Pre-salt carbonate reservoir by X-ray computed microtomography

• Published in: Journal of petroleum science & engineering Vol. 144; pp. 113 - 120
• Main Authors: Teles, A.P., Machado, A.C., Pepin, A., Bize-Forest, N., Lopes, R.T., Lima, I.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.08.2016
• Subjects: Carbonate; Carbonates; Computation; Microfocus; Porosity; Pre-Salt; Reservoirs; Rock; Subterranean; Tomography; Wormholes; X-ray; X-rays; VES; µXCT; XCT; FRT; Carbonate; Microfocus; ROI; VOI; Tomography; X-ray; Porosity; PVBT; Pre-Salt
• ISSN: 0920-4105; 1873-4715
• DOI: 10.1016/j.petrol.2016.03.008

The purpose of this study is to evaluate the pore space evolution of a rock sample from the coquina region of the subterranean Pre-Salt carbonate reservoir formation (later referred simply as coquina sample) subjected to hydrochloric acid flow through the whole sample. For that purpose, X-ray computed tomography with a microfocus source was used in order to evaluate the porous media space. The results show that the branches of the wormhole divert away from the areas near the main channel and the quartz volume decreases after acidification. From the porous space 3D model it could be verified that, although the acid reacts with the most porous part of the medium, the wormhole also crosses regions of lower porosity. Such a process leads to an increase in the total porosity of the carbonate rock. [Display omitted] •The size and pattern of the wormhole also depends on factors like acid concentration and pumping rate.•Microtomography is employed to inspect porosity evolution and quartz distribution.•The branches of the wormhole divert away from the areas near the principal channel and the quartz volume decreases after acidification.