Premium
In situ investigation of phosphonate retarder interaction in oil well cements at elevated temperature and pressure conditions
Author(s) -
KupwadePatil Kunal,
Boul Peter J.,
Rasner Diana K.,
Lapidus Saul H.,
Leao Juscelino B.,
Johnson Kenneth D.,
Thaemlitz Carl J.,
Büyüköztürk Oral
Publication year - 2020
Publication title -
journal of the american ceramic society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.9
H-Index - 196
eISSN - 1551-2916
pISSN - 0002-7820
DOI - 10.1111/jace.17373
Subject(s) - materials science , portlandite , diffusion , chemical engineering , mineralogy , retarder , silicate , calcium silicate , ettringite , analytical chemistry (journal) , cement , chemistry , composite material , portland cement , thermodynamics , chromatography , physics , engineering
The effect of a high‐performance retarding additive in oil well cements was investigated under elevated temperature (165°C) and pressure (1000 psi) conditions via in situ synchrotron‐based X‐ray diffraction (XRD) and quasielastic neutron scattering (QENS) techniques. Under these temperature and pressure conditions, crystalline calcium silicate hydrates (C–S–H) are formed through the cement hydration process. From in situ XRD experiments, the retardation effect was observed by a change in the rate of the appearance of 11 Å tobermorites as well as a change in the rate of the α‐C 2 SH generation and depletion. QENS analysis revealed that the retardation effect was related to the non‐conversion of free water to chemical and constrained water components. A high presence of free water components was attributed to a decrease in 11 Å tobermorites along with slower consumption of the quartz and portlandite phases. Furthermore, QENS results infer that the water molecules experienced confinement in the restricted pore spaces. The retarder inhibited this initial water confinement by slowing the bulk diffusion of free water in the confined region.