The energy business research and consulting firm Douglas-Westwood Ltd . concluded through a recent, major research program that, from 2014-2020, the international oil and natural gas industry will need to drill more than 670,000 wells in order to meet demand forecasts, the firm said Feb. 26.

The firm’s World Development Drilling & Production Forecast states that by 2020, global oil and natural gas demand will have increased 17% from 2013, noting that in 2020, the number of wells will have to exceed 106,000, but in 2013 the number of wells was more than 79,000.

“As the easiest-to-access oil and gas reserves deplete, each year we have to drill more and more wells for less and less production per well. Over the period, numbers of development wells drilled need to grow 35% to enable oil and gas production to meet an expected demand growth of 17%,” said chairman John Westwood .

He added, “This effect is most marked onshore where by 2020 we expect production to grow by 15%, whereas offshore production should grow at 21% due to developments in deepwater.”

Matt Cook , a geologist for Douglas-Westwood leading the drilling and production modeling program, added, “In 2013, 113 deepwater oil and gas development wells were drilled, but by 2018 this number should reach over 400. Meanwhile, production will grow from 6 MBOE/d to 9.5 MBOE/d.”

Andy Jenkins , a Douglas-Westwood researcher, noted that different countries face “very different situations” for the future. He said Norway’s oil production should increase slightly by 2020, through improved recovery in existing fields, as well as greenfield projects, such as the Goliat and Johan Sverdrup fields.

Matt Loffman , a senior analyst for Douglas-Westwood, noted that the U.S. has made gains in oil and natural gas production over the last two years, adding that “as rigs are focused on oil-targeted wells in the future, onshore oil well completions are set for a 36% increase by 2020.”

The Forecast noted that “traditionally productive regions are in decline and face a variety of futures,” but also noted that onshore activity will dominate the future, “accounting for 97% of well completions and 71% of global output.”

Douglas-Westwood Ltd., based in Faversham, Kent, U.K., provides market research and consulting to the international energy sector.