Electricity from flared gas in oilfields

[royp]

TL;DR Summary

Can we use the ‘waste’ gas being flared in oilfields to generate electricity?

Hi,
I recently read the following article on BBC online: "Revealed: Huge gas flaring emissions never reported (https://www.bbc.co.uk/news/science-environment-62917498)". Can they not use the ‘waste’ gas from flaring to generate electricity? Is it not feasible or economically viable? Do they need to (expensively) clean the gas before feeding to the generating system?

Thanks

 

[russ_watters]

Can they not use the ‘waste’ gas from flaring to generate electricity?

Yes. See also: landfill and sewage gas. I consulted on a project at a sewage treatment plant that aimed to do just that, with both the sewage digestion off gassing and the next door landfill.

Is it not feasible or economically viable?

I guess they figure it isn't or they'd already be doing it. For landfills and sewage plants there is a payback, particularly for sewage plants that need a lot of heat (to keep the bugs warm) and electricricity (pumps, mixers) locally. I think oil rigs already use it for electricity, but storing or using all the gas for electricity would take a lot of infrastructure. On-shore fields not as much.

But natural gas has always "suffered" from being too cheap.

Do they need to (expensively) clean the gas before feeding to the generating system?

They do need to clean it if it is from sewage or a landfill, but it isn't a big problem and I don't think flare gas from oil wells has that problem.

What is probably needed is legislation to mandate recovery.

 

[anorlunda]

Oil pipelines use gas extracted to run turbines that plump the oil. But those turbines aren't floating.

It is vastly more expensive to build secure structures at sea.

The relevant question is, "can the same money be spent some other way to better protect the environment?"

 

[russ_watters]

BTW, the link says the BP and Shell have committed to eliminating all but emergency flaring by 2025 and 2030, respectively.

 

[BWV]

Gas from a field has a widely varying BTU content from the processed NG from the tap. Gas from the field also can have a host of other petrochemicals (rich vs dry gas - see https://www.shaledirectories.com/blog-1/wet-natural-gas-vs-dry-natural-gas-whats-the-difference/). So off the shelf generators can not handle this as fuel, however there are specialty generators used in the Oil and Gas industry that can use gas from the wellhead. These generators are used for local power for the rigs and other needs, if the gas source is abundant enough to produce utility-scale electrical, then it’s more economical to build a pipeline, process the gas and add it to existing networks

 

[Lnewqban]

Copied from
https://en.wikipedia.org/wiki/Routine_flaring

Traditional uses​

Global data from year 2012 indicates that 15% of all associated gas was flared or vented, while 85% was utilized or saved for the following economic benefits:

1. re-injection into the oil reservoir for secondary recovery, tertiary recovery, and/or longer-term storage. (58%)
2. transmission to a trading hub for distribution to short-term storage and refinery markets. (27%)

Other uses​

The following list includes other existing commercially viable alternatives to routine flaring and venting that can be performed on-site or nearby:

1. liquid fuels production with Flare Gas Recovery Systems (FGRS) and trucking to consumption markets.
 a. natural gas liquid (NGL) extraction from the flare stream using mobile equipment.
b. portable compressed natural gas (CNG) production.
c. portable liquefied natural gas (LNG) production.
d. small-scale gas to liquids (GTL) conversion.

2. electricity generation with portable engines or microturbines.

3. heat generation for water treatment or other industrial processing at the wellpad.

A 2019 report from the U.S. Department of Energy states a likely reason oil companies may be slow to embrace either existing or advanced FGRS technologies is "legal, regulated flaring is the least risky option and does not require learning how to apply new technologies or modifying existing contracts and operating practices."

 

[royp]

Dear All,
Many thanks for all your valuable insights shared and I am also grateful for the clarifications.

Best wishes...