Total reserves: 0.1 to 0.7 trillion BOE
The “deep” in ultra-deep refers to the depths plumbed by floating oil rigs (typically, anything beyond 5,000 feet). But the more important depth is the distance from the ocean floor to the oil itself. It’s not easy to start an excavation a mile or two underwater, much less one that continues on for several more miles underground (the current record, set in 2009 in the Gulf of Mexico, is nearly seven miles). But an ever-expanding drilling fleet is deploying new techniques in horizontal drilling, sub-sea robotics and “four-dimensional” seismology (which geologists use to track oil and natural-gas deposit conditions in real time) to rapidly expand output. Although fewer than half the world’s ultra-deep provinces have been fully explored, deepwater output in the past decade has more than tripled, to 5 mbd, and it could double again by 2015.
As the Deepwater Horizon disaster made clear last year, though, tapping this resource can involve significant external costs. The pressure in ultra-deep reservoirs can reach up to 2,000 times that at sea level. The oil within can be extremely hot (up to 400°F) and rife with corrosive compounds (including hydrogen sulfide, which when in water can dissolve steel). And the pipes that rise from the seafloor are so long and heavy that the platforms supporting them must be extraordinarily large simply to stay afloat. The biggest discovery in decades, Brazil’s “pre-salt play,” meanwhile, is defended by a 1.5-mile-thick ceiling of salt, which had the beneficial effect of absorbing surrounding heat and keeping the oil from breaking down—but which also, in doing so, congealed the oil into a paraffinic jelly that drillers must now thin with chemicals before they can extract it.
Not surprisingly, ultra-deepwater oil is some of the most expensive in the business. A single drilling platform can cost $600 million or more (especially if the deepwater is in the Arctic, where rigs must be armored to withstand Force-10 winter storms and hull-crushing ice floes), and companies can easily spend $100 million drilling a single ultra-deepwater well. The result of all this effort is a modest EROEI--from 15:1 all the way down to 3:1.
Thus, even as companies scramble to improve safety, most of the research and development in the ultra deep will focus on saving money and energy. Remotely controlled, steerable drill heads, for example, allow companies to drill multiple bores from a single platform (thus lowering costs and the aboveground footprint) and to follow the path of narrow oil seams, greatly increasing oil output. (The record for a horizontal bore, set by Exxon near Russia’s Sakhalin Island, is also about seven miles.) To further cut drilling costs, companies will steadily boost rates of penetration with more-powerful drill motors, drill bits made of ever-harder materials and, eventually, a drilling process that uses no bits at all. Tests at Argonne National Laboratory suggest that high-powered lasers can penetrate rock faster than conventional bits, either by superheating the rock until it shatters or by melting it.
Costs will further recede as companies develop more-accurate “multi-channel” seismic prospecting techniques that will, by combining up to a million seismic signals, help them avoid the ultimate waste of drilling into empty rock. And to better measure the oil reservoirs themselves, companies are creating heat- and pressure-resistant “downhole” sensors (similar to devices NASA developed to monitor rocket engines) that communicate to surface computers via optical fiber.
As the volume of data rises, the industry will also create more-powerful tools to analyze it, from monster compression algorithms (courtesy of Hollywood animators) to entirely new computing architectures. “If we go to a million channels [of seismic data], then we need petaflop computation capability, which we currently do not have,” says Bruce Levell, Shell’s chief scientist for geology. To get that capability, oil firms are working with Intel, IBM and other hardware firms. In the future, Levell says, the oil business “is really going to drive high-performance computing.”single page