Post-Burn Core Analysis of Samples from the Pricetown I U.C.G. Field Test, Pricetown, West Virginia: Phase I

摘要

Visual description, mineralogic, and geochemical analyses of post-burn cores from the Pricetown, West Virginia, U.C.G. Field Test have produced several conclusions. Alteration effects due to the burn, in order of increasing temperature, consisted of patchy to pervasive staining and saturation of shale and coal by tar (produced during the coal burn). Dehydration and subsequent formation of microfractures has occurred in associated shales. Oxidation of pyrite has occurred. Intense baking, resulted in darkening of coal and an increase in hardness of the shale. Destruction of kaolinite, chlorite, and illite has occurred. The percent of quartz in the shale has increased. Crystallization of high-temperature mineral phases, such as mullite (Al sub 6 Si sub 2 O sub 3 ), cristobalite (SiO sub 2 ), which are typical of ceramic materials, has occurred. Crystallization of pyrrhotite and magnetite from a melt, which was derived from pyrite has occurred. Melting and cooling of adjacent shale, produced highly vesicular, pumice-like rock. Melting and cooling of shale produced medium-crystalline rock, lacking vesicular structure. Coking and burning of coal, resulted in vesicular coal fragments and ash. Core C-3, located more in the heart of the test zone, showed extensive evidence of physical and mineralogical alterations that were the result of the coal burn. These included staining and saturation by coal tar in the shale overlying the coal; oxidation of pyrite; microfracturing; baking of shale, including discoloration and development of vesicular structure; melting of shale, resulting in highly vesicular rock; melting and slow cooling of the shale, resulting in medium-crystalline rock; destruction of pyrite and precipitation of pyrrhotite and magnetite from an iron-sulfide melt; destruction of clay minerals; and a rubble-filled cavity. (ERA citation 06:028059)