ROCK PHYSICS ANALYSIS WITHIN CARBONATE ROCK FACIES OF RAJAMANDALA FORMATION IN CIKAMUNING SECTION

• Main Author: Budhi Khorniawan, Wahyu
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/37257
• Institution: Institut Teknologi Bandung

Carbonate is a complex substance of composition, grain geometry, and diagenesis process that has the unique physical characteristics, different from the others (e.g. siliciclastic). Hence, the specific method should be applied to characterize carbonate rock more detail and accurate. In this study, rock physics is used for determining carbonate rock behavior based on its physical properties. Rajamandala Formation in Cikamuning section is selected as object study to illustrate the relationship between carbonate rock facies and diagenesis attributed to rock physics parameters. Generally, this study can be divided into several stages start from preparation, data collection, data interpretation and analysis, and integration result and reporting. There are 10 lithofacies in the study area, including foraminiferal grainstone, skeletalcoralclast grainstone, skeletal-intraclast rudstone (breccia), platy coral boundstone, foraminiferal packstone, skeletal - coralclast grainstone, large benthic foram grainstone, coral boundstone, compositional grainstone, and compositional breccia grainstone. These facies are covering at least 4 diagenesis environment : marine phreatic, meteoric phreatic, burial diagenesis and meteoric vadose, deposited in Late Oligocene based on paleontology analysis. Rock physics analysis result show that rock with a lack of skeletal grain and matrix dominated has relatively high-Vp and Vs value, and vice versa. In addition, lithofacies is also affect to Vp and Vs value where porosity is the key properties in the same lithofacies. coral boundstone and foraminiferal wackestone facies (both of them are matrix dominated) have high value of rigidity and incompressibility represent that these facies hard to be slide over, whereas compositional grainstone facies (grain dominated) is less rigid and incompressible showing that it will be slide over effortlessly.