North Arthit field in Gulf of Thailand is a gas condensate field, but also has oil reservoirs that produce from number of wells. This paper explains the implementation of in-situ gas lift and gas dump flood technologies to increase production and improve recovery from a partially depleted oil reservoir in North Arthit field. A simulation study was performed to understand reservoir characteristic, drive mechanism and expected oil rate prior to the field implementation; the study results were to allow cross flow within the tubing to dump high-pressure gas from a deeper gas reservoir into the oil reservoir to increase reservoir pressure and sweep the oil to a nearby producer. This successful pilot work has opened up the opportunities for other small oil pools in Gulf of Thailand. A proper design of the in-situ gas lift and dump flood will significantly improve the oil recovery.