A confluence of entrenched domestic demand, mounting calls for U.S. exports of LNG and modest production growth – all factors forecast to endure – propelled natural gas futures above $9.00/MMBtu in August and could keep upward pressure on prices for years.

Such was the assessment of analysts who spoke Tuesday at the LDC Gas Forum Rockies & West in Denver. Prices have more than doubled this year and recently approached the highest levels since 2008.

ConocoPhillips’ Matthew Henderson, senior market analyst, said natural gas prices would inevitably ebb and flow with seasons and in response to major news developments. On the whole, though, the bull case is firmly intact given elevated cooling demand in an era of persistently hot summers, including most recently the third...