Publications

Maximizing oil production at all phases of field life while ensuring prudent reservoir management is the main goal of production optimization in the Banyu Urip field. Each phase of field life poses different challenges that must be managed through innovations, relentless collaboration, and agility across functions. This paper aims to share various initiatives and strategies to address key challenges of production optimization during early, initial full-field production, plateau, and recent off-plateau stages in the field, with more emphasis on the subsurface aspect. Extensive dynamic subsurface data collection and rigorous analysis as part of the reservoir surveillance plan at all field stages are crucial to gain a better reservoir understanding and defining a strategy to maximize oil production. The Banyu Urip field's depletion strategy is to maximize oil recovery by maintaining reservoir pressure through full voidage replacement with water and gas injection. In the initial phase, oil was produced through three series of early production facilities: Early Production Facilities (EPF) in 2009, Early Oil Expansion (EOE) in 2014, and Well pad B First Oil (WPBFO) in 2015. At this stage, the well's capacity was estimated to be higher than the processing facility's capacity. Accordingly, efforts to optimize production were focused on the debottlenecking of surface facilities, resulting in more than 80,000 bopd oil production, higher than the design capacity of each early facility which total 70,000 bopd. When the full field of Central Processing Facilities (CPF) started up by the end of 2015, Banyu Urip production continued to ramp up until it reached its maximum capacity of 185,000 bopd within five months. An integrated well and reservoir performance evaluation led to opportunities to increase production beyond 185,000 bopd. As more oil was produced, the Gas Oil Ratio (GOR) was expected to increase since the Gas Oil Contact (GOC) had moved down, approaching the perforation zone. With the limited gas handling capacity, production optimization shifted towards managing gas production. Gas Shut Off (GSO) program was implemented to slow the increase in GOR. Perforation addition and reperforation campaigns were initiated to enhance the well's capacity. These integrated efforts enabled Banyu Urip to produce at a higher plateau rate of up to 225,000 bopd compared to the 165,000 bopd in the Plan of Development (POD) target. Furthermore, the higher rate was maintained for three years longer than planned. In late 2020, when the field started to decline due to gas handling capacity constraints vs. gas production, the formation of calcium carbonate scale on wells on the surface and downhole added complexity to managing the wells' capacity. A scale inhibitor injection program was implemented to prevent scale deposit at the choke. Subsurface programs such as reperforation and acid wash were executed to mitigate downhole scale. Effective wells management through a wells’ optimization strategy was also carried out. These programs helped manage production decline and maintain Banyu Urip's position as a strong contributor to national oil production.