ExxonMobil Cepu Limited (EMCL), as the operator of Banyu Urip field in Cepu Block, Indonesia, observed several oil wells with high Gas Oil Ratio (GOR) after several years of production. Oil production curtailment was expected due to limited surface gas handling capacity. Additional stand-off against reservoir gas cap shall be established by performing top perforation interval shut-off to reduce GOR and maximize oil production. Perforation shut-off became more challenging due to high concentrations of H2S and CO2, relatively high reservoir temperature, long perforation interval, and total losses experience. The remedial solution required a V0 “gas-tight” qualification, live well execution, induced minimum to no formation damage, and provided minimum reduction of tubular Inner Diameter (ID) post remedial work to avoid significant production impact and allow future wireline tools deployment. Considering the high profile of Banyu Urip field, which currently produces ~29% of Indonesia’s oil production, EMCL selected the fit-for-purpose remedial method with the highest probability of success. The hydroformed expandable casing patch (patch) with Corrosion Resistance Alloy (CRA) material and its top-down expansion method was evaluated and selected. The re-designing of inflatable element was performed to improve durability in high temperature and verified by laboratory testing. Patches were installed and overlapped to cover the top perforation interval. Seals on top and bottom of the patch extremities formed V0 “gas-tight” sealing mechanism against the casing. The patches were deployed utilizing a smart coiled tubing. All patches were successfully installed as per plan. The wells were brought online with significantly reduced GOR post patches installation. This was the first installation of the patch utilizing smart coiled tubing and ~90 feet Coiled Tubing (CT) tower in sour wells within any ExxonMobil affiliates. The detailed technical preparation, strong safety culture and leadership as well as relentless learnings application have delivered a successful project to reduce Banyu Urip wells GOR and enable EMCL to maximize oil production.