PERTAMINA EP's Niru field development objective is to drain attic oil from the X0 sandstones. The thin fluvial-distributary channel environment of the reservoir brings drilling challenges due to the complex reservoir geometry and uncertain lateral continuity. A horizontal well was planned in order to maximize recovery of oil in this mature oil field well.

An integrated LWD solution combining fit for purpose real time measurements from a continuous rotating bottom hole assembly, bed boundary mapping tool, formation images with real time correlation and Geosteering software, was used to steer the well in real time. The real time monitoring of petrophysical parameters, enabled TD to be decided after achieving maximum exposure to the reservoir. In addition, the analysis of dip information from formation images acquired while drilling enabled an important update to the field geological model to be made, while highlighting the limitations in reservoir characterisation of using data from vertical wells drilled into a structure with lateral variations

The improved understanding of the reservoir, as well as the capabilities of the deep directional resistivity tool to locate and map the roof of the reservoir while drilling, enabled the wellbore to be maintained 1 -2 m below it.

This precise and accurate positioning of the wellbore in the reservoir sweet spot, resulted in the sustained production of oil at a rate almost 4 times higher than expected with the addition of low water cut.

The benefits of real time bed boundary mapping and well placement techniques have led to both a better understanding of the X0 channel sandstones reservoir, and a direct change in the development strategy of the field by Pertamina EP. This will now include further horizontal wells, which are now considered to be essential to the successful development of the Niru field, for draining oil from the thin (2-4 m thick) reservoir, which was previously thought to be impossible.

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