Characteristics of high temperature cementitious lost-circulation control materials for geothermal wells

Technical Report · Wed Jan 01 04:00:00 EST 1986

DOI:https://doi.org/10.2172/5751118· OSTI ID:5751118

Sugama, T; Kukacka, L E; Galen, B G; Milestone, N B

Materials systems have been formulated for the in situ conversion of water-based bentonite drilling fluids into cementitious lost-circulation control materials (CLCM) for use in geothermal wells at temperatures up to 300/sup 0/C. The formulations consist of a cement hardener, a borax admixture, and a fiber glass bridging material which are added to the bentonite fluids. Evaluations of the properties of the slurry and the cured CLCMS revealed that the ions supplied by dissociation of the borax in the CLCM slurry acted to suppress the bentonite hydration and retarded the hardening rate of the cement at elevated temperatures. The CaO-SiO/sub 2/-H/sub 2/O (C-S-H) phases formed during curing of the CLCM play essential roles in improving the quality of the hardened CLCMs. It was observed that xonotlite-truscottite transformation resulted in strength reductions and increased water permeability. The plugging ability of fiber glass depends on the conentration and fiber size. The silicate ions dissolved by hot alkaline disintegration of the fiber glass were chemisorbed with Ca/sup 2 +/ ions from the cement and led to the precipitation of C-S-H compounds on the fiber surfaces, which improved bond strength at the matrix-fiber interfaces.

• Research Organization: Brookhaven National Lab., Upton, NY (USA)
• DOE Contract Number: AC02-76CH00016
• OSTI ID: 5751118
• Report Number(s): BNL-51960; ON: DE86010866
• Country of Publication: United States
• Language: English

Related Subjects

15 GEOTHERMAL ENERGY
150901* -- Geothermal Engineering-- Drilling Technology & Well Hardware
BUILDING MATERIALS
CEMENTS
CHEMICAL COMPOSITION
DATA
DRILLING FLUIDS
EXPERIMENTAL DATA
FLUIDS
GEOTHERMAL WELLS
Geothermal Legacy
INFORMATION
LOST CIRCULATION
MATERIALS
MINERALOGY
NUMERICAL DATA
PHYSICAL PROPERTIES
WELLS