Implementation 3D inversion of gravity data to identify potential hydrocarbon reservoir zones in West Timor Basin

Abstract

A gravity survey has been carried out in the area of West Timor, East Nusa Tenggara to identify the existence of basin structures. The existence of reservoirs and trap structures are two important parameters in hydrocarbon exploration. Geologically, Timor possibly an area known to have a very complex geological structure. This complexity can be the main factor that causes the demotivation of geologists in exploring hydrocarbons. There are many indications of hydrocarbons in the form of oil and gas seeps on the surface, especially in East Timor. But most of them are not confirmed in the field, and only a few are even found in West Timor. The method used in this study is analyzing and 3D inversion modeling gravity data. The analysis was carried out using spectrum analysis and the second vertical derivative of the complete Bouguer anomaly (CBA). From the gravity parameters confirmed by geological data, the results indicate that in the study area there are basin and basement structures thought to be formed from unconformably of andesite igneous rock and tight send sediment with a density value of about 2.5 gr/cm3 . The average basement depth is about 5.5 km with its forming structure is the reverse/thrust fault with Northeast to Southwest its strike orientation. While in the southern part, especially in the central basin area, there is indicated a layer of sand sediment that is quite thick with a density value of about 2.2 gr/cm3 and has the potential to become a hydrocarbon reservoir.