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HOUSTON (Dow Jones)–Exxon Mobil Corp.’s (XOM) $31 billion bid for XTO Energy Inc. (XTO) marks the biggest endorsement yet for the exploitation of unconventional natural gas resources–and signals a growing will to carry the expertise that has revolutionized gas production beyond the North American gas market.

In a statement released Monday, Exxon Chief Executive Rex Tillerson said that the deal would benefit consumers “here and around the world,” and help the company develop natural gas and oil resources globally. Exxon, the world’s largest publicly traded oil company, has recently scooped up unconventional gas assets in Poland, Germany, Hungary and Argentina. If brought online, these resources could help feed major markets that currently face unsteady supplies.

Exxon plans to manage its global development of unconventional gas resources from XTO’s Fort Worth offices. But overseas exploitation of shale reserves face challenges not found in Texas, Oklahoma or Louisiana, where an extensive network of service companies has helped small independent natural-gas producers drill intensively in the hard-to-crack rock formations that trap the unconventional gas. Also, the geology of overseas shale plays isn’t understood as well as the U.S. rock formations, and obtaining mineral rights in foreign countries can be more difficult, said Robert Clarke, manager of unconventional gas services for the energy consultancy Wood Mackenzie.

Still, overseas markets present opportunities for potential new gas supplies. “There is vast resource potential abroad and those resources would serve undersupplied local markets,” Clarke said.

Big Oil is having an easier time accessing shale and other unconventional plays than conventional oil resources–where they have to fight off zealous governments and national oil companies.

Until recently, major oil companies have been reluctant to take big bets on shales because they are relatively new areas of exploration that require intensive drilling. It was mostly aggressive, independent natural-gas producers that learned to drill horizontal wells into tight rock formations and crack them with a high pressure solution of water and sand, releasing the gas trapped within.

But in the past two years several international oil companies have been kicking the technology’s tires. Statoil ASA (STO, STL.OS), BP PLC (BP, BP.LN) and ENI SpA (E, ENI.MI) have struck deals that give them a foothold in U.S. shale plays.

“Every major oil company is thinking about getting into these shale plays both in the U.S. and globally, the question is how,” said David Rockecharlie, co-head of the energy investment banking group for Jefferies & Co Inc. Barclays Capital and Jefferies advised XTO on the transaction.