Coal Petrology and Geochemistry of Upper Coal Zones and Lower Coal Zones of Nyalau Formation from Merit-Pila Coalfield

Tertiary coal from Merit-Pila coalfield, Central Sarawak, Malaysia were analysed
their regional ranks and petroleum generative potential. Total organic carbon contents
(TOC) of coals range from 18.1 to 71.4 wt. % and S2 values coal are range from 0.57
to 5.48 these shows that this coal really have high potential to be a source rock
potential. The hydrogen index value ranging from 166 to 1069 mg HC/g, this indicate
that these coal are dominated by type III kerogen and are thus considered to be
generated mainly gas-prone and limited oil-prone. This is supported by the presence
of significant amount (35-65% by volume) of gas prone vitrinite maceral. Vitrinite is
among the most common of gas-prone macerals in coal. The Thermal Alteration
index (TAI) also shows that these coal are an immature coal and only can produced
mainly gas and a limited amount of oil. This is supported by the Tmax values ranges
from 348 to 423 °C which shows that these coal are immature. Although these coal
from Merit-Pila coalfield have a high potential to be source rock potential but the
hydrogen index value shows that it only can generated mainly gas and limited oil and
supported by the vitrinite maceral is dominated in the coal. The coal also immature to
generate oil from the thermal alteration index supported by the Tmax value.