Senate Energy and Natural Resources Committee Chairman Ron Wyden (D-Ore.) is seeking information about oil and refining market conditions from the Energy Department ahead of a committee hearing on gasoline price increases.

Wyden – who recently said this year’s price surge has “no reasonable explanation” – wrote to the Energy Information Administration (EIA) asking whether there have been disruptions in oil imports or production, refining capacity, or pipelines that explain the surge.

“This most recent round of gas price increases has come at a time of year when gas prices are typically at their lowest point, but that has not been the case this autumn and winter,” states Wyden’s letter Monday to EIA Administrator Adam Sieminski.

Wyden plans to hold a hearing this spring.