The oil wells in Prudhoe Bay not only produce oil but water. The water either comes from the ocean through the sea bed, or from injection wells where water is used to push oil out of the rock towards production wells. Up here, the wells may produce as much at 70% water, which companies must dispose in an environmentally friendly fashion. The disposal isn’t cheap.
HAL’s answer is our conformance product line. There are polymers we can pump downhole which can slow down the flow of water out of the rock while leaving the oil flow untouched. Initial results indicate we can shut off 50% of a well’s water flow, knocking a Prudhoe Bay total water cut to 35%. This is good, because if we don’t pull the water out of the hole, we don’t have to get rid of it.
The water that comes out of the hole is usually brackish, and that means either trucking it away or diluting it. CNet reports that Altela is developing an on-site still using waste heat from oil rigs to distill up to 90% of the water into potable water.
The combination of these two technologies stands to save oil producers significant cost. Environmental friendliness with pay-out: that’s sustainability in my book. 
That’s good work. And in the real world, sustainability means exactly that — environmentalism with a pay off. Because otherwise you can’t afford to sustain operations to do it.
Duke Energy in Indiana is planning to experiment with using liquified CO2 to pump natural gas and oil (maybe, I think, I don’t have the details), and so also sequester CO2. Have you heard of this idea? Do you think it will work and be affordable?
CO2 is a fun animal. It can dissolve in petroleum and drop the viscosity, so you get a double assist in getting hydrocarbon from the rock into the wellbore: pneumatic pressure on less viscous oil. We also do hydraulic fracturing with CO2 foams, because the low pH foam that results from dissolved CO2 has been shown to be friendlier to clay formations. Clay formations can swell with water and plug the well off down below.
Since one of the ways CO2 is normally obtained is through combustion, using CO2 from their power generation plants could be a reasonable recycling scenario. Unfortunately HAL doesn’t have any presence in Indiana, so I haven’t seen anything in the area.