Perpustakaan Digital ITB

The oil and gas industry faces significant challenges in optimizing hydrocarbon recovery. Despite prolonged primary recovery, many mature fields leave over 80% of the original oil in place (OOIP). The “N” reservoir layer with lenses reservoir characteristic in the mature “Klayan” Field, located in Cirebon, West Java, was discovered in 1976 and forms part of a multilayered reservoir system identified as a potential development target. As of March 2025, the recovery factor was 14.5%, with current condition only one active producer (SHM-31) yielding 14.1 BOPD and 23 wells shut in. The field’s compartmentalized reservoirs and multiple faults present significant development constraints, while its heterogeneous characteristics are reflected in permeability from 7.45 to 1736.55 mD. This study used reservoir simulation to evaluate three development strategies include idle well reactivation, infill drilling, and waterflooding, based on a Movable Oil Index (MOI) analysis to identify potential development areas. Reactivating four idle wells (SHM-06, SHM-16, SHM-09, and SHM-21A) increased the recovery factor by 0.84%. Drilling two infill wells (ID-03 and ID-05) increased the recovery factor by an additional 1.6144%. Waterflooding slightly improved reservoir pressure but did not enhance the recovery factor. This was primarily due to high heterogeneity, the presence of permeability streaks, and a high mobility ratio, which caused early water breakthrough. Combining reactivating four idle wells and drilling two infill wells (R156-ID-03-05) increased the recovery factor by 1.8753% and generated an estimated net economic benefit of USD 63.2 million. This is the most technically and economically feasible scenario in the study.