Publications

The Central Sumatra basin is well known as an oil field province in Indonesia. More than one hundred fields from giant to small size reside in the area. Most of the fields which were discovered in the 1930s to the 1980s era are currently old and mature. The Albit field is one of them. This field was discovered in the early 1950s, started production in 1966 and reached peak production in the 1970s. Continuous efforts to maintain this field’s production were conducted by drilling infill and horizontal wells, and by fracturing, waterflood and optimization of existing wells. After more than 50 years of production, the field no longer has opportunities for further development. The latest production data of existing wells and existing geological models do not support further drilling of new wells in this field. A new group of geologists was challenged in recent years with the target rejuvenating the Albit field production. Different from approach commonly applied to generate infill wells by relying on recent production of existing wells, methodology used by the team consists of : 1) revisiting existing geological model and production history of existing wells, 2) identifying root cause of recent conclusion that this field has no further opportunity for development, 3) generating workplan for geological model update and opportunity identification. The team’s evaluation identified a major root cause that there is a gap in existing geological models compared to current team’s finding. The existing geological models which were built in the 2008 era need updates. The Team then worked to update the model by starting from scratch of geological data including seismic and well logs. Seismic cube data was enhanced by multi-attribute evaluations to help fault and stratigraphic reinterpretations. The interpretation is also supported by current technology of fast-speed processing and visualization that enables rigorous and enhanced interpretation. The resulted new model has successfully identified several structural plays (new attic locations) for new well opportunities. New wells have been proposed to target the newly interpreted structural play of attic locations. Log data from drilling results show multiple oil columns in several reservoirs. Production in the recently found oil columns has contributed to the rejuvenation and doubled the production of the Albit field. The new acquired log data, besides benefiting the new wells themselves, are also helpful for identifying the remaining oil in existing wells for workover opportunities. This success exemplifies the importance of “returning to geology” in rejuvenating old and mature fields. Continuously returning to basic geological data is essential. This practice can become a model for other fields in Central Sumatra.