Reviving the Mature Handil Field: From Integrated Reservoir Study to Field Application

Abstract

Abstract The Handil field, discovered in 1974, is a giant mature oilfield located in the Mahakam Delta, Indonesia. The field consists of 555 accumulations and was developed by more than 350 wells with conventional oil recovery methods: natural depletion and peripheral water injection. After many reservoirs have been water-flooded, in order to recover the tertiary oil, EOR lean gas injection project was started in November 1995 on five reservoirs. The project was successful and extended to the other six reservoirs in 2000. However, the field production continued to decline from 200,000 BOPD in the late seventies to 12,500 BOPD in 2003. An integrated study on the largest EOR reservoir was performed to assess the projects' performance, including 3D geo-modeling, reservoir simulation and chemical tracer injection. The study permitted to track the main effects of the gas injection and define reservoir management guidelines for the other lean gas injection reservoirs. In the same time, dynamic synthesis has been performed in all accumulation in Handil Field with objective to identify potential "by-passed" oil and un-drained areas. Following the study, an intensive Light Work Over campaign has been launched and three pilot wells, each with different completion type, have been successfully put on production and became the model for the next Handil development wells; horizontal well equipped by gas lift to recover viscous sandy reservoir in very shallow zone, gravel pack equipped by ESP to recover sandy reservoirs in shallow zone and monobore multi-target well equipped by gas lift to recover reservoirs in main zone. The production has been increased by nearly 100 percents, from 12,500 BOPD in 2003 to 23,000 BOPD nowadays. Integrated reservoir study and the successful application of Light Work Over and Infill Well to recover "by-passed" oil and un-drained areas, supported by EOR techniques to maintain the reservoir pressure and sweep the tertiary oil, become the key elements to revive the mature Handil Field. Introduction The Handil field is located in the Mahakam Delta, East Kalimantan, Indonesia. The field comprises of 555 unconnected accumulations/reservoirs in structurally stacked and compartmentalized deltaic sands. The reservoirs are trapped by Handil Anticline which is cut by a major impermeable fault dividing the field into two compartments, North and South. The reservoirs are found between 200 mSS and 3500 mSS, in the surface of 10 km long and 4 km wide.