OREANDA-NEWS. Monthly US crude production estimates for January through May of this year were revised downward by between 40,000 b/d to 130,000 b/d as the US Energy Information Administration (EIA) implemented a new methodology to calculate the output figures.

The new data includes fresh production numbers for June 2015 and revised figures for the first five months of the year.

Production in June averaged 9.3mn b/d, a drop of about 100,000 b/d from the revised figure for May, EIA said. The complete revised data set and a more indepth analysis will be released later today.

The largest revisions in volume in the first five months of 2015 are in Texas, the top oil producing state, where figures were revised downward by between 100,000 b/d to 150,000 b/d. The revised numbers also include increases in output in the Gulf of Mexico of between 10,000 b/d to 50,000 b/d.

The EIA's new methodology has shifted to a method which includes a direct survey of oil producers in 15 states, including Texas, Oklahoma, Louisiana, North Dakota and New Mexico. The agency uses a similar method to calculate monthly natural gas output.

The EIA made the changes because crude production data from state agencies — including the Texas Railroad Commission — is often incomplete or lagging.

The survey-based approach improves estimates by representing more than 90pc of US oil production, the EIA said.