Deep Dive Waterflood Performance of TPN Field for Future Development

Abstract

Waterflood practice is still the most popular in Indonesia. Not only because of the relatively simpler and cheaper investment, but also because Indonesian typical reservoir and oil characteristic still referring that waterflood is the first alternative to develop the field. Moreover, by the advancement of the software features that available in market, it provides more detailed capability to model and analyze waterflood operations and performances. Waterflood injection has already begin at TPN field since 1991 with the first pilot project, followed by the bigger scale operations at 1995. But the achieved result is shown to be not optimum. The oil increment effect is just seen at the first phase of injection, then it gradually decreasing but followed by higher water production. It suspected as the result of lack evaluation details when the project is evaluated and prepared. Injection scheme did not seem have a good pattern, based on historical field/ well schedule and production. The challenge is getting bigger with the existence of several major faults and reservoir geology complexity. However, due to the good initial response together with considerably high remaining oil reserve, the team decided to continue develop the field with waterflood injection. The current team observed and re-evaluated the waterflood performance since 1995 until 2015 with the help of the latest computing and visualization technology of waterflood evaluation. The new method uncovered reservoir uncertainty with the measurable way in order to quantify the subsurface progress.
This study elaborates whole aspect evaluation, highly supported by tracer and streamline analysis to understand the reservoir and the wells behavior. Continued with well by well performance analysis which shown injector to producer pairing, relation between production and injected water, which then also come up with injector well efficiency to be used as reference of the future field development plan.
Several scenarios applied in this study such as producer to injector conversion, increase injection rate, add injector as well as the combination of the alternatives. The simulation result showed the sensitivity of each alternative and told us what is the optimum scenario to develop the field.