Precipitation of vaterite (CaCO₃) during oil field drilling

Abstract

Vaterite, a CaCO3 polymorph, is a rare mineral that is said to be metastable under all known conditions. According to the literature, vaterite precipitated from carbonate solution recrystallizes spontaneously to calcite or aragonite. Yet vaterite has been identified in hard tissues of organisms, in gallstones, in contact metamorphic aureoles, in zones of thermal metamorphism, in a meteorite, and in cone-in-cone concretions. Newly precipitated vaterite has formed at the expense of carbonate rock in drilling fluids in wells of New York, Michigan, Nevada, Texas, and New Zealand. Petrographic examination reveals a light brown core of CaaSiO5 surrounded by a colourless rim of vaterite. The ~lSOpo a of New York vaterite is -12.4%o and that of the Michigan vaterite is -17.67/0o, which reflect the oxygen isotopic composition of meteoric freshwater used in drilling. The ~13CpD B value of --19.27/oo for New York vaterite and that of -17.67/oo for Michigan vaterite suggest that natural gas dissolved original carbonate in the subsurface. Drilling records from both wells indicate that natural gas was released into the drilling muds from the formations exposed at the time vaterite was encountered. Crossplots of the oxygen and carbon isotopic ratios overlap those of spurrite rocks in thermal metamorphic zones in Israel. A C-14 radiocarbon analysis of the Michigan vaterite gave an age of 953 + 39 yr. BP. 88.8__+0.6% is modern carbon and 11.2% is dead carbon. Hence this carbon, and therefore the vaterite, is essentially modern. A sample of the New York vaterite yielded a modern age.

Nanobacteria-like calcite single crystals at the surface of the Tataouine meteorite

“…Actually, this pseudomorphic replacement has only been experimentally reproduced by Maciejewski et al (38) at 733 K, which is not relevant to the temperatures in the Tataouine sand. In solution, the transformation takes several hours (39) and consists in the recrystallization of calcite through the dissolution of vaterite with no conservation of the morphology (38,40). Moreover, rod-shaped vaterite particles similar in shape to the Tataouine calcites have not been synthesized.…”

Bacterially mediated mineralization of vaterite

“…In nature vaterite has been found in calcareous sediments (Benton et al, 1963), metamorphic rocks (McConnel, 1960) and drilling muds (Friedman and Schultz, 1994). It has also been found in portland cement (Cole and Kroone, 1959), ancient plasters (ca.…”

Optimization of Enzyme-Mediated Calcite Precipitation as a Soil-Improvement Technique: The Effect of Aragonite and Gypsum on the Mechanical Properties of Treated Sand

“…Despite a metastable relative to calcite, aragonite has higher Mohs hardness than calcite, namely, 3.25-4.00 and 3.00, respectively [22,23].In addition, the other calcium carbonate polymorph of vaterite may also be promoted during the precipitation process. Vaterite is an essential constituent of Portland cement and was found during oil field drilling [24]. As the calcium carbonate polymorph, aragonite and vaterite have the similar XRD patterns [25][26][27][28].…”