Well log analysis and geochemical data to identify source rock and hydrocarbon reservoir: Northeast Java Basin study case

Abstract

Comprehensive characterizarion methods are carried out to determine accurate source rock and reservoir identification. Geochemical data has become a critical part of recent unconventional exploration and development. However, due to high cost of geological core extraction and analysis, geophysical wireline logging tools have become the primary source of downhole measurement of geomechanical properties. This study covers an integrated approach at defining geochemical report derived from geological core extraction and analysis and its relationship with geophysical wireline logs of 5 (five) wells at Northeast Java Basin. Geophysical wireline logs can be utilized to identify reservoir and source rock intervals in the early stage of well drilling. However, the well logs that directly measure the hidrogen content of the kerogen do no exist. Consequently, it is utilized for source rock evaluations and calculation of Total Organic Carbon (TOC) which are most commonly include sonic, density, gamma ray, neutron, and resistivity. The Van Krevelen diagram has been applied to all 5 (five) wells that indicates 2 (two) of them have potential gas - kerogen type III/IV with marginally mature to mature source rock. The integration of well logs and geochemical data greatly improves the accuracy and understanding of the controls of reservoir quality and source rock. It can be used for further step of knowing basin potential and its prospect level.