Norwegian oil companies are now expected to spend 171 billion kroner (18.6 billion euros, $19.8 billion) on domestic investment, 10 billion less than estimated in August, the country's statistics bureau SSB said.
The fall was seen mostly in prospecting for new resources, it said.
Investment estimates for this year remained unchanged at 192.7 billion kroner, implying an expected 11.3 percent drop in 2016.
Oil is Norway's key economic driver, and the Scandinavian kingdom's central bank has already cut leading interest rates in half over the past year to a current 0.75 percent to help the country's growth prospects.
Further cuts are in the pipeline, it has hinted, and analysts say the next easing could come as early as December.