Publications

TK reservoir is a tight and heterogeneous sandstone formation. After a massive fracturing campaign and fast production build-up in the early production, the exploitation led to a severe pressure decline. Water injection project was then implemented in 2009, since which this pressure maintenance has been the life blood of this reservoir. However, after fifteen years of production and eight years of continuous water injection, there were still areas with low reservoir pressure leading to suboptimal production and low recovery factor. To improve the pressure maintenance which ultimately will result in improved oil recovery in this reservoir, a waterflood optimization project was initiated. The main fit-for-purpose strategy applied was to increase water injection rate through a convert-to-injector (CTI) campaign. The optimization was designed based on the estimation of incremental water injection rate required to increase the reservoir pressure. This step was then followed by strategic selection of wells that would be converted to injectors. After the best candidates were selected, the project were then executed and closely monitored. Significant improvement in waterflood surveillance and monitoring was also done to ensure the optimum waterflood performance. As the results of the on-going project, the reservoir pressure has been increasing and decline rate arrested. Significant reserve addition of 2.48 MMSTB had been enabled by this initiative through various activities, like infill drilling, hydraulic fracturing, artificial lift conversion, and shut-in well reactivation that would not be possible if the optimization was not realized beforehand. The present work addresses the reservoir and operational aspects of the journey of TK waterflood optimization. The workflow, analyses, and lessons shared in this paper are highly applicable to a low oil price environment, as they show how fit-for-purpose methodology and technology can lead to improved field performance.