dc.description.abstract | The objective of this study is to evaluate the potential of unconventional oil-gas in Taiwan by analyzing mineral composition and pore structure of HC potential reservoirs in the Western Foothill Belt. Pliocene(Cholan Fm, Chinshui sh) and Miocene(Yutengpin ss, Kuantaoshan ss, Shangfuchi ss, Tungkeng Fm, Guanyinshang ss, Talu sh and Peiliao Fm) samples were collected along stratigraphic profiles of Chuhuangkeng and Mingte Reservoir, Miaoli County, NW Taiwan. The porosity, permeability, TOC, thermal maturity, and mineral composition of samples were examined after a series of geochemical experiments. The results shows Peiliao Fm has the highest TOC value among all samples (0.258%wt.) and Tmax value from Rock-Eval pyrolysis also shows that Peiliao Fm has the Tmax(449°C) within oil window. Hydrogen index and Quality index are positively correlated with thermal maturity, identifying Peiliao Fm has the highest oil-gas potential. Porosity and permeability were positively correlated in semi-log plot. Comparing the results of porosity and permeability with TOC and mineral composition shows that TOC is irrelevant to porosity and permeability, whereas samples with higher fragile mineral content(quartz and feldspar) has higher porosity and permeability, indicating mineral composition is the main controlling factor of porosity and permeability of reservoir rocks. SEM observation is also applied to observe pore structure in micro scale, suggesting micro-fracture can improve porosity and provide extra space for oil-gas preservation. | en_US |