This study presents a coupled hydrodynamic and oil transport numerical model to study the spread of Karawang oil spills at sea due to well-kick failures. This model uses the 3D configuration of ROMS-CROCO in the Java Sea. The model has a resolution of 1 km, 25 vertical layers, and runs from January 2019 to September 2019. Temperature, salinity, sea surface height, ocean currents, and harmonic tides are derived from global models and applied to open boundaries. Hourly atmospheric datasets during model simulation are forced as flux input in the surface. The 3D profile of the flow generated by the model is converted to the GNOME oil transport model format as mover type input to disperse the oil. The hydrodynamic model shows that the result has a good agreement with in-situ data and observation with mean of correlation exceeding r>0.8 for sea surface height and sea surface temperature. Compared with radar satellites, oil spill dispersion shows the same scattered trend as satellite data. Backward modelling shows oil particles returning to the initial spill location. The oil spill was moving westward, and some are stranded on the coast between Karawang and Bekasi.