Extending the Life of Mature Oil Field by Converting Gas Wells into Oil Wells

Abstract

The Handil field is a giant mature oil field in Indonesia. It has been producing since 1975 with current recovery factor for oil is 49% and gas is 57%. Cumulatively, oil had been produced around 855 MMstb and gas around 1.68 Tcf. Now, from this field, oil is being produced at 20,000 bopd, gas at 75 mmscfd and water at 130,000 bwpd. One of the feasible and economic ways to recover the remaining oil at this late stage of field production is by doing a Light Workover technique. This technique aims to change the well status without pulling out the existing completion. This technique is considered the optimum way to maintain the field production performance up to now. One of Light Workover technique is to do re-completion by inserting smaller completion inside existing completion. An innovative spool adapter was utilized to be able to run smaller completion and sit above existing wellhead. Hence, from three (3) depleted gas wells that were converted into oil wells, all wells are still producing and economically had been paid out the intervention cost. This technique is considered applicable for a mature oil field where some gas wells had been depleted and oil layers are exist.