Renewable energy is expected to make up 15% of the energy we use by 2035. By that same year, world energy demand will likely have increased by 50% as consumption grows in the developing world. The bulk of this energy burden will fall on the shoulders of fossil fuels. Though there is always speculation about the end of the world's oil reserves, high oil prices and technological advancements have opened the doors to reserves in hard-to-reach places that have been closed for years, unlocking billions of barrels of oil in the process.

Deepwater
Technology has created extensive opportunities to tap into deepwater reserves. In a little more than a decade, the number of vessels drilling deepwater wells has climbed from 20 to 200, with more on the way. Deepwater oil production has climbed significantly over the same period, from 1.5 million barrels a day in 2000, to roughly 7 million barrels a day now.

Two key technological developments have made this possible. First, seismic imaging has improved so that geologists can study reservoir maps 15,000 feet below the ocean floor. Second, improved alloy drill bits now stand up to the heat and pressure in these hard-to-reach places.

Transocean (NYSE: RIG), the world's largest offshore drilling contractor, stands to benefit significantly from the increase in deepwater drilling, as experts estimate production may double by 2020. Only 10% of the world's deepwater fields have been explored and drilled, potentially leaving the door open for significant growth beyond that.

National Oilwell Varco (NYSE: NOV) is another deepwater expert that may reap the rewards of increased offshore activity. The company has a solid relationship with Brazil's Petrobras, and recently announced it was acquiring a Danish company that manufactures flexible pipe and other components for developing offshore operations. The move increases National Oilwell Varco's position in the deepwater game.

Really cold deepwater
The U.S. Geological Survey estimates that 25% of the world's remaining undiscovered conventional oil and gas reserves are located in the Arctic. Knowing that, however, doesn't make producing it any easier. Besides the frigid temperatures, icebergs, and months of darkness, oil companies have to contend with government regulations that have by and large limited Arctic offshore development. Perhaps with good reason, as oil spills in these northern waters would be extremely difficult to clean up.

Still, as technology improves and these arctic missions become more feasible, expect drilling. Royal Dutch Shell (NYSE: RDS-B) has already received conditional approval to begin drilling exploratory wells this summer. Shell estimates there are 25 billion barrels of oil in the Alaskan Arctic.

Plenty of the other big guns are slowly building up their Arctic arsenals. Statoil (NYSE: STO) operates a gas field in the Barents Sea, north of the Arctic Circle, where it's estimated 250 million barrels of oil are hidden; ExxonMobil has teamed up with Rosneft in Russia, and Chevron is exploring north of Canada.

Hydraulic fracturing
Back on land, technology has revitalized oil and gas production. Horizontal drilling and hydraulic fracturing have dramatically changed domestic production, though environmental concerns threaten to slow growth in some regions.

The greatest concern with hydraulic fracturing surrounds the water. An obscene amount of water is used to fracture each stage of every well -- we are talking about millions and millions of gallons -- and when that water comes back up from the well, it is likely to contain varying levels of toxins.

Here again, technology may change the story. GasFrac Energy Services, a Canadian company traded on the Toronto Stock Exchange, has developed a method to use a liquid propane gel in place of water. The gel holds two advantages over water. First, the gel is recaptured after a frac and can be reused over and over. Second, it may yield a "better" frac, allowing more gas to be produced than current methods using water.

GasFrac has used the gel on more than 400 wells from Canada to Texas, but will almost certainly need regulatory approval before widespread adoption in the United States. That being said, a process that doesn't involve massive amounts of water will certainly appeal to the fracking future of desert regions like the Middle East and China.

Oil sands
Finally, we have our beloved and beleaguered oil sands. This is a resource that has been around forever, but until recently, was too costly to produce. The high price of oil has allowed production from Canada's oil sands to grow to 1.5 million barrels per day since 2000, when numbers were closer to 600,000 barrels. Analysts say that number could increase by 200,000 barrels a day every year for the next 20 years, if environmental concerns don't stymie production and pipeline development.

This is where technology comes in. Advances like steam-assisted gravity drainage have alleviated some of the environmental concerns, while refining improvements have cut emissions. There is still room for improvement, however, and E-T Energy is leading the way.

The company is developing a method to extract bitumen from the oil sands using electrical current. The impact on the environment is insignificant from start to finish, and the process can access reserves that are unreachable with other methods.

French energy power Total (NYSE: TOT) formed a partnership with E-T Energy last April and stands to gain from the development.

Foolish takeaway
Technology likely has us wedded to fossil fuels for the next two decades. Anything that can make exploration and production faster and cheaper is going to be in high demand, especially as companies are forced to target tricky reserve locations. The high price of oil makes such exploration possible right now. With that in mind, consider these three stocks that stand to gain while oil sits above $100.