> Think about it - if these formations were not leakproof on geological scale, there wouldn't be any oil and gas for us to extract in the first place. Leakproo

> Think about it - if these formations were not leakproof on geological scale, there wouldn't be any oil and gas for us to extract in the first place. Leakproof to one substance doesn't necessarily mean leakproof to another. Heavy oil is hydrophobic and a less mobile, volatile molecule than CO2. Methane otoh is lighter. That said, CO2 capture mostly works in scenarios where you have a highly concentrated stream AND can afford the weight and energy penalty of the capture apparatus. Good on big chemical/industrial plants, refineries and maybe gas power stations, and worth doing for that reason - industrial processes are some of the hardest to replace or avoid of the big emitters. Likely useless for vehicles and aircraft. It's very hard to feed 8Bn people without a whole lot of Haber-Bosch though, and hard to do that without methane in, CO2 out. All the more reason to cut down on wasteful uses of both food and energy.