CO{sub 2} reaction with hydrated class H well cement under geologic sequestration conditions: effects of flyash admixtures
- United States Department of Energy, Pittsburgh, PA (United States). National Energy Technology Laboratory
The rate and mechanism of reaction of pozzolan-amended Class H cement exposed to both supercritical CO{sub 2} and CO{sub 2}-saturated brine were determined under geologic sequestration conditions to assess the potential impact of cement degradation in existing wells on CO{sub 2} storage integrity. The pozzolan additive chosen, Type F flyash, a by-product of coal combustion, is the most common additive used in cements for well sealing in oil-gas field operations. The 35:65 and 65:35 (v/v) pozzolan-cement blends were exposed to supercritical CO{sub 2} and CO{sub 2}-saturated brine and underwent cement carbonation. Extrapolation of the carbonation rate for the 35:65 case suggests a penetration depth of 170-180 mm for both the CO{sub 2}-saturated brine and supercritical CO{sub 2} after 30 years. Despite alteration in both pozzolan systems, the reacted cement remained relatively impermeable to fluid flow after exposure to brine solution saturated with CO{sub 2}, with values well below the American Petroleum Institute recommended maximum well cement permeability of 200 {mu}D. Analyses of 50:50 pozzolan-cement cores from a production well in a sandstone reservoir exhibited carbonation and low permeability to brine solution saturated with CO{sub 2}, which are consistent with our laboratory findings. 16 refs., 4 figs., 1 tab.
- OSTI ID:
- 21187044
- Journal Information:
- Environmental Science and Technology, Journal Name: Environmental Science and Technology Journal Issue: 10 Vol. 43; ISSN ESTHAG; ISSN 0013-936X
- Country of Publication:
- United States
- Language:
- English
Similar Records
Rate of CO2 Attack on Hydrated Class H Well Cement under Geologic Sequestration Conditions
Related Subjects
36 MATERIALS SCIENCE
ADDITIVES
BRINES
CARBON DIOXIDE
CARBON SEQUESTRATION
CARBONATES
CEMENTS
CHEMICAL REACTION KINETICS
CURING
DECOMPOSITION
ENVIRONMENTAL EXPOSURE
FLY ASH
HARDNESS
MICROSTRUCTURE
MIXING RATIO
PENETRATION DEPTH
PERMEABILITY
POROSITY
SUPERCRITICAL STATE
WASTE PRODUCT UTILIZATION