Facies and Stratigraphic Sequences Analysis Based on Well Log, Mud Log, and 2D Seismic Data of GHC Field, Baong Formation, Aru Sub-Basin, North Sumatera Basin

The Baong Formation is one of the formations that have hydrocarbon potential in the Aru Sub Basin, North Sumatra Basin. However, there is still limited geological information in the area including the Analysis of Sequence Stratigraphy. The geological information is also needed to easier find out the distribution of potential layers of oil and gas in order to maximize exploration results. The method used in this research was Electrofacies Analysis to show the appearance of rock grain size and geological processes that affect formation. Well--Seismic Tie and interpretation of the horizon along with structures was conducted to produce a Time Structure Map and correlate the sequences in well logs and 2D seismic cross-section to define the lateral distribution of each sequence. Based on the third-order sequence, the Baong Formation was divided into two system tract types: Lowstand System Tract (LST) and Transgressive System Tract (TST). Maximum Flooding Surface (MFS) is the lower boundary of LST, Transgressive Surface (TS) is the boundary between LST and TST, and Maximum Flooding Surface is the upper boundary of TST. Based on fourth-order sequence, each system tracts was divided into seven parasequences with Flooding Surface as the boundary. The research area can also be interpreted into a conceptual model of the hydrocarbon system.