Abstract:
The Mannar Basin plays a vital role in petroleum exploration in Sri
Lanka, and its Barracuda exploration well was drilled up to 4206 m in depth.
The objective of the current study is to identify mineralogy using Fourier transform infrared (FTIR) and X-ray diffraction (XRD) analyses. The FTIR and
XRD analyses confirm the presence of quartz, feldspar, clay minerals (e.g.,
kaolinite, montmorillonite), calcite, and hematite in all marlstone and mudstone
samples. These sedimentary rocks can be identified as potential petroleum
source rocks in the Mannar Basin. Quartz, carbonate, and hematite cementations
are directly reduced porosity and permeability, and thus primary migration of
hydrocarbons from potential source rocks. Clay minerals act as a seal for
hydrocarbon migrations in the Mannar Basin. A variety of dominant clay
mineral assemblages allows the reconstruction of several paleoclimatic
chronozones in warm/wet and arid climates. In contrast, feldspar dissolution
promotes the primary migration of hydrocarbon from potential petroleum source
rocks. Consequently, this study concluded that common minerals such as quartz,
carbonate, and hematite are associated with the trapping and binding processes
of hydrocarbons.
