The OBR has cut its estimate of tax income from the North Sea between 2020 and 2041 by a quarter, to £40bn.
The fall is down to lower production forecasts over the next few years.
But its assessment was dismissed as "stuff and nonsense" by Scottish First Minister Alex Salmond.
The Scottish government has argued that the OBR figures are based on a "very low estimate of future total production", which resulted in them being more pessimistic than other estimates, including those produced by industry body Oil and Gas UK.
The OBR was created by George Osborne in 2010 in one of his first acts as chancellor to provide independent economic forecasts and analysis of the UK's public finances.