Publications

Over time, there has been a gradual decline in the available reserves of oil and natural gas. The decline in oil and gas reserves is influenced by various factors beyond just industry demand. While reactivating aging oil fields may mitigate the decline, it does not solely address the root causes. It is imperative to reassess aging oil fields with robust historical production records to explore strategies for sustaining production levels amidst reserve depletion. Lamongan Sub-Basin has one of the largest gas and oil reserves in the region. As of February 2021, statistical data from the Directorate General of Oil and Gas reveal that the estimated oil reserves in East Java stand at approximately 499 million barrels (MMSTB). This information underscores the region’s significance as a contributor to Indonesia’s overall oil resources. The reevaluation of the oil fields in Lamongan Sub-Basin involves a crucial step in characterizing unconventional reservoirs, particularly those formed and distributed within source rocks. This process utilizes advanced techniques such as seismic inversion and multi-attribute analysis, gaining a comprehensive understanding of geology and reservoir characterization. The primary parameters include the total porosity and water saturation. This study involves ten 2D seismic lines and one well to generate synthetic wells, facilitating the evaluation of the distribution of potential zones as sources of unconventional reservoirs. Based on analysis of logs and tuning thickness, two target zones are identified within the Ngimbang Formation. The interpretation result indicates the presence of potential shale rock within the Ngimbang Formation, suggesting its viability in two distinct areas. The first area is in the eastern region, denoted as Target Zone 1. The second area is located in the southern region, particularly along the ATB-7 and ATB-4 lines, referred to as Target Zone 2.