Mineralogy and Microscopy of Some Sedimentary Rocks in Sarawak

Sedimentary rocks are composed principally of detrital mineral grains. The physical properties of the mineral grains which compose the sedimentary rock determine grain matrix framework compaction resistance as well as the texture of the rock itself. The study on mineralogy (crystal structure, chemistry, physical properties of mineral, descriptive mineral) and microscopic (grain size, textural maturity, shape, isotope geochemistry) properties of selected reservoir quality will be conducted on the sedimentary rocks belonging to Nyalau Formation, Sarawak. The lithofacies structure, bed geometry and etc will also be studied for the purpose of correlation and mapping. Nyalau Formation was chosen because of its’ proximity location to Baram Formation (known for its oil and gas exploration and production). Currently, there are very limited informations related to mineralogy and microscopic properties in some sedimentary rocks in Sarawak. There is a lack of information in specific petrophysical properties such as Thermal Conductivity and poro-perm. There is also lack of information in relationship between fabric characteristic and their critical reservoir properties in these rocks. The possible relationship between the fabric variability and behaviour of some critical petrophysical properties in the sedimentary rocks need to be evaluated. Methodology, which is sample collection and laboratory examination, will be carried out. Samples will also be taken back to the laboratory for analysis. The mineralogy examinations will be performed by using X-ray Diffractometer (XRD), Scanning Electron Microscope (SEM), Fourier Transform Infrared Radiation (FTIR), Ultra Violet (UV), EGME Testing, Total Organic Compound (TOC), and Thin Section. Mercury porosimeter will be used to relate the pore size distribution and permeability to the mineralogical data while Thermal Conductivity will be used to estimate and understand the heat transfer or temperature between rock facies, as the feature is important in enhancing basin modelling and reservoir characteristic.