Characterisation and modelling of physico-chemical degradation of cement-bases materials used in oil wells
Title: Characterisation and modelling of physico-chemical degradation of cement-bases materials used in oil wells
Author(s): N. Neuville, E. Lecolier, G. Aouad, D. Damidot
Paper category : conference
Book title: International RILEM Symposium on Concrete Modelling - ConMod '08
Editor(s): E. Schlangen and G. De Schutter
Publisher: RILEM Publications SARL
Publication year: 2008
Pages: 191 - 198
Total Pages: 8
Nb references: 24
Abstract: Cement-based materials are used in oil and gas industry for cementing oil wells. The main role of the cement sheath is to permanently isolate all subsurface formations penetrated by the well. Long-term durability of cement-based materials used in oil wells is a major concern for oil and gas industry. Therefore, understanding of physico-chemical processes leading to cement degradation is a priority. In this study, we are presenting characterisation of chemical and physical properties for cement pastes exposed to leaching tests, and the modelling of theses changes with a reactive transport model, HYTEC. The leached samples were cured with two different procedures aimed at reproducing the two different boundary conditions of the cement paste into the well. The results reported structural and chemical differences between the cement paste observed after the two types of curing, leading to a different behaviour after a three months leaching test in brine at 80°C. It was thus clearly demonstrated that curing conditions clearly influenced the degradation mode and kinetics during leaching.
First simulations using the reactive transport code HYTEC with a simplified cement chemistry, allowed us nevertheless to reproduce some experimental results during cement pastes leaching, as mineralogical and physical changes.
Online publication: 2009-06-15
Publication type : full_text
Public price (Euros): 0.00