Kutei Basin is located in East Kalimantan, Indonesia. In this study, it has been identified the structural controls and hydrocarbon prospects of the Kutei Basin using gravity method. Interpretation of faults structure controls and basin delineation have been derived from the second vertical derivative anomaly. Then, it has been conducted subsurface geological modeling using gravity forward and inverse modeling to determine distibution of subsurface density contrasts.The final result of modeling are the contour map of top basement and sediment thickness. Based on gravity anomaly can be analyzed that Kutei Basin has faults structure with almost NE-SW directiontrendingfolds in the presence(Antiklinorium Samarinda) and the structures are reverse faults and wrench faults. It can be identified that there are two sub-basins in Kutei Basin, i.e. Upper Kutei Sub-Basin with continental basement and Lower Kutei Sub-Basin with oceanic basement. Based on gravity modeling, it can be estimated the density contrast of basaltic rocks in oceanic basement is 0.17 gr/cc and granitic rocks in continental basement is 0.07 gr/cc. Kutei Basin has deep top basement with maximum sediment thickness are approximately 9.4 km. Supported by geology data and hydrocarbons play, the Kutei Basin could be as hydrocarbon prospects area.
Key words: gravity, Kutei Basin, second vertical derivative, forward modeling, inverse modeling, top basement, hydrocarbons