Yes in America and maybe other places where Oil rigs are energy is wasted in the form of gas flaring, where excess or useless energy is burned off into the atmosphere. A good example is maybe you have an oil rig set up to extract oil but also have to deal with clearing out pockets of methane first. The methane must be flared and burnt off.

With a Bitcoin miner instead of flaring the methane off you can consume most of it and instead of wasting it you use it to mine Bitcoin. Someone can correct me if I am wrong but I think this is about the same or maybe a little less of a carbon footprint compared to flaring the gas and burning it into the atmosphere but the important thing here is it isn't being WASTED.

One of my only concerns about this is people consuming energy that does not need to be consumed and using Bitcoin to market as some way to save energy that wouldn't otherwise be wasted or excess. IE: spinning up old coal plants, going out of your way to find methane pockets, etc.