GEOLOGY AND STUDY OF NATURAL FRACTURE CHARACTERISTICS IN BASEMENT ROCK OUTCROP IN THE LAU DAMAK REGION AND SURROUNDINGS, BAHOROK DISTRICT, LANGKAT REGENCY, NORTH SUMATRA PROVINCE

• Main Author: Kemal Fatah, Yuri
• Format: Final Project
• Language: Indonesia
• Subjects: Geologi, hidrologi & meteorologi
• Online Access: https://digilib.itb.ac.id/gdl/view/72717
• Institution: Institut Teknologi Bandung

The demand for hydrocarbons in Indonesia continues to rise, hence additional hydrocarbon reserves is required. One of its sources is basement controlled by structures. As one part of the North Sumatra Basin, The Lau Damak area and its surroundings are composed of metasedimentary basement that exhibits intensive fracturing. This study on the characteristics of natural fractures was conducted using linear scanline and window scanline methods around the Lau Batu Garut Fault to assess the potential for new reservoir in the fractured basement. The Lau Batu Garut Fault which classified as a left normal slip fault, exhibits a width of 39m fort the fault damage zone. The formation of natural fractures in the research area is influenced by three episodes of natural fracture formation, spanning from the Early Triassic to the present. The intensity of these fractures ranges from 3.8 fractures/m to 29.6 fractures/m while the measured density falls within the range of 18.3 fractures/m² to 116 fractures/m². The fractal dimension of the natural fractures attribute within The Fault Damage Zone of Lau Batu Garut and outside it varies between the range of 0.976 to 1.468. The porosity in the research area varies between 0.08% and 1.52%. The measured permeability of cubes ranges from 0.03 darcy to 10.61 darcy, while the permeability of matchsticks ranges from 0.03 darcy to 7.96 darcy.