Rock Physics Anisotropy of Some Clastics of Machinchang Formation, Langkawi and Semanggol Formation, Perak

Exploration for oil and gas demands a success in the discovery of economical petroleum reservoirs; thus a precise understanding of the reservoir properties is a must to ensure the successfulness of the reservoir evaluation. Recently, the discovery of anisotropic behaviour of rocks is proven; collapsing the conservative understanding of the isotropy of any properties within a rock body. With sense of direction becoming a crucial factor in understanding the behaviour of rock properties, the importance in understanding the anisotropy of rock will be a decisive factor in appraising petroleum reservoirs. Therefore, in this project, the main objective is to study the changes in rock physics properties values with respect to direction particularly to validate the presence of such anisotropic behaviour and predicting its origins. The study is merely focusing on two great interests which are the geological studies of clastic rocks as well as the rock physics anisotropy studies of elastic, electrical and petrophysical properties. Two study area of two different locations, age and depositional environment was chosen namely the Machinchang Formation and Semanggol Formation. The methodology for this research is involving two approaches starting with geological fieldwork for both formations, and followed by several laboratory analysis of the rock samples collected. From the geological fieldwork, the lithology and sedimentary facies are analysed; and geological map and cross section are produced. From laboratory work, sonic acoustic, porosity-permeability, and resistivity are measured to analyse the elastic, petrophysics and electric properties of rock samples. Petrography and mineralogy analysis using thin section and XRD testing are also conducted. From the results obtained, interpretation for each properties generally as well as in term of individual anisotropy are done first and combined later to produce a rock physics anisotropy model based on the geological cross section created earlier. With that, the presence of anisotropy for both formations are validated, the type of anisotropy as well as corresponding factors and origins of such behaviour are deduced. The rock physics anisotropy for both formations are compared in temporal and spatial domains.