Heterogeneous porosity distribution in Portland cement exposed to CO2-rich fluids |
| |
Authors: | Gaëtan Rimmelé Véronique Barlet-Gouédard Olivier Porcherie Bruno Goffé Fabrice Brunet |
| |
Affiliation: | 1. Université Paris-Est, IFSTTAR, MAT, F-75732 Paris, France;2. Université Paris-Est, Laboratoire Navier, Ecole des Ponts ParisTech, IFSTTAR, CNRS, F-77455 Marne-la-Vallée, France;1. Department of Civil Engineering, Indian Institute of Technology Delhi, 110016 New Delhi, India;2. Laboratory of Construction Materials, EPFL STI IMX LMC Station 12, CH-1015 Lausanne, Switzerland |
| |
Abstract: | Efficient and safe storage of injected supercritical carbon dioxide (CO2) underground is now one potential solution for reducing CO2 emissions in the atmosphere. Preventing any CO2 leakage through a wellbore annulus after injection is a key to maintaining long-term wellbore integrity. Most wells in depleted oil and gas fields may be re-used to inject CO2. These wells were mostly cemented with conventional Portland cement. It is thus crucial to study how such cement behaves at depth in CO2-rich fluids.Set cement samples are exposed to CO2 fluids under pressure and temperature to simulate downhole conditions. The degraded cement exhibits significant mineralogical changes and heterogeneous porosity distribution. The bulk porosity evolution, as well as local porosity gradients through the samples, is quantified using combined mercury porosimetry and back-scattered electron image analysis. Both techniques show an initial sealing stage related to calcium carbonate precipitation plugging the porosity, followed by a dissolution stage marked by a significant increase of porosity. |
| |
Keywords: | |
本文献已被 ScienceDirect 等数据库收录! |
|