The amount of natural gas from shale is expected to signifcantly grow in upcoming years, particularly in the United States..
The U.S. Energy Information Administration reports:
" ...natural gas production worldwide is projected to increase from 342 billion cubic feet per day (Bcf/d) in 2015 to 554 Bcf/d by 2040. The largest component of this growth is natural gas production from shale resources, which grows from 42 Bcf/d in 2015 to 168 Bcf/d by 2040. Shale gas is expected to account for 30% of world natural gas production by the end of the forecast period.
"Although currently only four countries—the United States, Canada, China, and Argentina—have commercial shale gas production, technological improvements over the forecast period are expected to encourage development of shale resources in other countries, primarily in Mexico and Algeria. Together, these six countries are projected to account for 70% of global shale production by 2040.
"In the United States, shale gas production accounted for more than half of U.S. natural gas production in 2015 and is projected to more than double from 37 Bcf/d in 2015 to 79 Bcf/d by 2040, which is 70% of total U.S. natural gas production in the AEO2016 Reference case by 2040
The full EIA report is here.