The technology that fueled the U.S. shale revolution could breathe new life into old oil fields outside of North America.

More than 170 mature oil plays worldwide have the potential from horizontal drilling and hydraulic fracturing to produce as much as 141 billion barrels (Bbbl) of oil, according to an IHS report on May 13.

Of the estimated 141 Bbbl of potentially recoverable oil using unconventional techniques, 135 Bbbl exist in plays that would likely require hydraulic fracture stimulation to produce. Roughly 6 Bbbl sit in plays that may not require hydraulic fracturing.

The top four countries include Iran, Russia, Mexico and China.

The resource has so far been difficult to tap. Global efforts to introduce new technology outside of the U.S. have been unfruitful. The U.K. and Poland have disappointing first attempts, the Council on Foreign Relations said. And China, with massive amounts of shale, is held back by water shortages, mountainous terrain and other problems.

In September 2014, the U.S. Treasury Department imposed sanctions on Russia that effectively neutralized work by major foreign service companies. The sanctions, related to the conflict in the Ukraine, prohibit the exportation of goods, services or technology for exploration or production of deepwater, offshore or shale projects.

About two-thirds of the potential oil lies in fields in the Middle East and Latin American countries, while the rest are relatively evenly distributed across the various regions of the world.

Many of the mature plays in these countries have only produced a small portion of the total oil in place due to their rock properties. Hydraulic fracturing could change that, said Leta K. Smith, director of upstream energy research at IHS and the principal analyst behind the analysis, in the report.

IHS, up to 141 billion boe potential, outside North America, fracking, graph

“Drilling horizontal wells allows access to thinner zones, where vertical wells are not commercially productive,” Smith said.

She said horizontal wells also allow engineers to connect compartmentalized portions of the reservoir with one well instead of many vertical wells, “which addresses cost and footprint considerations as well as increasing the well-to-reservoir contact ratio.”

While many of the top-15 countries identified in the report are access-limited for international oil companies, Mexico, in third-place, holds substantial incremental oil.

Mexico may see new investment in these types of resources with the upcoming opening of the country’s upstream sector, Smith said.

“For operators with experience in these drilling and completion techniques,” she said, “Mexico may be an attractive option for future investment, along with some of the 14 countries identified outside the Middle East, including Brazil, the U.K., Norway, Congo and Indonesia.”

The report also said modern seismic and measurement-while-drilling (MWD) technologies would allow operators to achieve better placement of fractures to take advantage of natural fracturing and other geologic features for maximizing production and avoiding water zones.

“Combined with other technologies developed for shale development, such as pad drilling, these improvements could breathe new life into some of these older, conventional fields,” Smith said.

IHS analysis cited the Saint Martin de Bossenay Field in France’s Paris Basin as an example that showed operators already leveraging some of the newer techniques to address different geologic and production challenges.

The Saint Martin de Bossenay Field was first discovered in 1959. The field’s wells were producing mostly water by 1996 and it was abandoned, according to IHS. Then, in 2005, another operator resurrected the site with non-fractured horizontal wells, since fracking isn’t permitted in France.

Recently, the field was redeveloped using modern technology, including seismic specifically targeting nonproduced portions of the field. Following redevelopment, the field’s recovery factor improved from 40% to 44%—adding 1 MMbbl to the proven plus probable reserves (2P reserves), the report said.

At CERAWeek 2015, Smith said the field’s reserves increases 10 MMbbl from 9 MMbbl.

Other examples used in the report include the Tahe Complex in China’s Tarim Basin and the Bir Ben Tartar Field in Tunisia.

Contact the author, Emily Moser, at emoser@hartenergy.com.