US cuts estimate for Marcellus Shale gas reserves
The US Energy Department cuts its estimate for natural gas reserves in the Marcellus shale formation by 66 %, citing improved data on drilling and production.
About 141 tcf of gas can be recovered from the Marcellus shale using current technology, down from the previous estimate of 410 tn, the department said in its Annual Energy Outlook. About 482 tcf can be produced from shale basins across the US, down 42 % from 827 tn in last year’s outlook.
“Drilling in the Marcellus accelerated rapidly in 2010 and 2011, so that there is far more information available today than a year ago,” the department said.
The estimates represent unproved technically recoverable gas. The daily rate of Marcellus production doubled during 2011.
The estimated Marcellus reserves would meet US gas demand for about six years, using 2010 consumption data, according to the Energy Department, down from 17 years in the previous outlook.
The Marcellus Shale is a rock formation stretching across the US Northeast, including Pennsylvania and New York. Shale producers use a technique known as hydraulic fracturing, which involves pumping water, sand and chemicals underground to extract gas embedded in the rock.
The US Geological Survey said in August that it would reduce its estimate of undiscovered Marcellus Shale natural gas by as much as 80 % after an updated assessment by government geologists. Shale gas will probably account for 49 % of total US dry gas production in 2035, up from 23 % in 2010, the Energy Department said.
Gas’s share of electric power generation will increase to 27 % in 2035 from 24 % in 2010, the report showed.
The department also said the US may become a net exporter of liquefied natural gas in 2016 and a net exporter of natural gas in 2021.
US LNG exports may start with a capacity of 1.1 bn cfpd in 2016 and increase by an additional 1.1 bn cfpd in 2019, the department said.