Publications

Fractured basement reservoirs have brought hydrocarbon exploration to a new level. A complex history of geological setting becomes a challenge in fracture mapping and distribution. A good fractured reservoir distribution should follow the Power-Law Distribution where two quantities change exponentially from dominant to less. The fractal dimension could infer geological context of homogeneity and heterogeneity. This research will focus on the potential reservoir of Jurassic Granite,Garba Formation in the South Sumatra Basin. Surface mapping was conducted to collect fracture samples. Outcrop data allows us to create a surface analog for advanced fracture attribute interpretation. A statistical approach is used in analysis of the data to determine the fracture zone, origin geometry, porosity, and permeability. The Garba Formation consists of granite, basaltic-andesitic dyike, quartz vein, and breccia. The fractures in the research area are related to fault systems with basement dominated by NW – SE and NE – SW trending structures. The cumulative distribution of fracture attributes follows the Power-Law Distribution and shows multi trend directions. The fractal dimesion of 3 fracture sets reveals the fracture origins where multi-stages of tectonic activities occured during the basement configuration. The standard deviation of apertures is 3.45 mm with range between 0.1 to 30 mm while the spaces is 0.12 m with range between 0.01 to 0.75 m. This can be categorized as a good reservoir. The simple experiment to measure the volume of reservoir is also plotted with log normal distribution showing storage capacity of up to 80%. The fracture characteristics of Garba Formation is homogeneous but also heterogenous at the same time and is classified as high potential reservoir through its response of origin, porosity, and permeability. This distribution however, cannot be the absolute evaluation in determining porosity of this unconventional reservoir but it can define the fracture system framework.