A preliminary evaluation of buldan coals (Denizli/western Turkey) using pyrolysis and organic petrographic investigations

Abstract

Buldan region is almost 45 km from Denizli (Western Turkey) province. Terrestrial sedimentary units are deposited throughout the Denizli Basin in age from the Early Miocene to Present. The coals are located in Middle Miocene Kızılburun Formation consisting of conglomerate, sandstone and mudstone lithologies. Coal samples were studied using standard total organic carbon (TOC) and kerogen pyrolysis analysis of the whole rock samples and organic petrographic methods. Average TOC content, S1 and S2 values of investigated coals are 45.5 wt.%, 2.12 mg HC/g rock and 72.20 mg HC/g rock, respectively. Potential yield values (PY, on average 74.31 mg HC/g rock) show that these samples have quite high hydrocarbon potential. Samples from the Buldan coal levels with moderate-high hydrogen index (HI, between 38 mg HC/g TOC and 301 mg HC/g TOC) values contain Type II and Type III kerogen. Although the investigated samples have high hydrocarbon potential (gas and/or oil – prone) and excellent source rock quality, average Tmax (419°C) and production index (PI, 0.04) values suggest that these samples are immature. Huminite/vitrinite (73.1%-83.4%) and inertinite (57.5%) maceral group are dominant in the studied samples. The predominance of telohuminite (especially ulminite) over inertinite (especially inertodetrinite) reveals that depositional environment of Buldan coals in a reducing environment. Average random huminite/vitrinite reflectance (Vr%) value of coals is 0.45% and indicates sub-bituminous B rank or brown coal. © SGEM2018.