CO2‐brine substitution effects on ultrasonic wave propagation through sandstone with oblique fractures

Ismael Himar Falcon‐suarez, Giorgos Papageorgiou, Zhaoyu Jin, Andrea Muñoz‐ibáñez, Mark Chapman, Angus I. Best

Research output: Contribution to journalArticlepeer-review

Abstract

Seismic monitoring of injected CO2 plumes in fractured storage reservoirs relies on accurate knowledge of the physical mechansims governing elastic wave propagation, as described by appropriate, validated rock physics models. We measured laboratory ultrasonic velocity and attenuation of P‐ and S‐waves, and electrical resistivity, of a synthetic fractured sandstone with obliquely aligned (penny‐shaped) fractures, undergoing a brine‐CO2 flow‐through test at simulated reservoir pressure and temperature. Our results show systematic differences in the dependence of velocity and attenuation on fluid saturation between imbibition and drainage episodes, which we attribute to uniform and patchy fluid distributions, respectively, and the relative permeability of CO2 and brine in the rock. This behaviour is consistent with predictions from a multi‐fluid rock physics model, facilitating the identification of the dispersive mechanisms associated with wave induced fluid flow in fractured systems at seismic scales.
Original languageEnglish
JournalGeophysical Research Letters
DOIs
Publication statusPublished - 29 Jul 2020

Fingerprint

Dive into the research topics of 'CO2‐brine substitution effects on ultrasonic wave propagation through sandstone with oblique fractures'. Together they form a unique fingerprint.

Cite this