Time correction to eliminate structural ambiguity on velocity anomaly in the upper cibulakan formation of ITEUNG field, northern West Java basin

Converting seismic data or structural maps from time to depth domain is very important in the stage of oil and gas exploration. Interpretation in time domain often produce inaccurate interpretation especially in zones under high velocity such as sub-salt or sub-carbonate. Under this zone, there are pull up velocity anomalies or pseudo-anticline. Otherwise in zones under low velocity such as water bottoms with sharp or fluctuating slopes (canyons), loose material overburden or rapid sedimentation, under detached electric normal faults and shale flaps, there are push down velocity anomaly or pseudo-syncline. The study area is in the Main and Massive Formation of ITEUNG Field, Northern West Java Basin where is proven to have petroleum potential. In the study area there are pull-up velocity anomaly or pseudo-anticline even though in reality they are just flat or even syncline due to the location in the zone under high velocity. This study aims to correct velocity anomaly by doing time correction and convert the time domain structure map into depth domain structure map with the time-depth curve method to eliminate structural ambiguity on velocity anomaly. The result shows that the map is obtained in the form of a depth domain structure map which is more accurate than the time domain structure map. Depth structure map make the interpretation more accurate because the structures in depth structure map is more similar to the original sovereignty after correlating with well data. In this present study shows that pull up velocity anomaly can be avoided so that interpretation can be done more accurately.