by Nefarious » Tue 06 Oct 2009, 21:02:03
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')It is not that hard to measure eroei. It is really a very simple method but takes some research and a lot of data.
One measures all the energy inputs into an energy gathering system. In the case of pretroleum production that means measuring the diesel, gasoline, and electricity to drill and complete a well and the collection system. It also means the measuring and amortizing (across the assumed depreciated life of the equipment and the total assumed production) the embodied energy in the casing, valves, pipes, GOSP, and refinery etc.
The offshore oil and gas industry is unique to any other type of industry on the planet. Each well that is drilled and produced is unique from any other well.
I will give you some very small examples of the changing variables when it comes to drilling and producing an oil well.First off only diesel is used.There is no gasoline, and the electricity that is produced is from diesel generators. Unless it is a production platform then most of the time the generators and compressors run off of natural gas that comes straight up out of the field.
To begin to see how much diesel is used to drill a well we have to ask some questions.Are you going to use a jack-up,a semi submersible,a drill ship. Each one requires different amounts of diesel to operate.If using a jack-up does it move under it's own power or do you have to use tug boats to move it into location? How many tugs? How far was the move from the last location?Burn a lot more diesel going 300 miles to a new location than 100 miles. Are you crew changing by helicopter or boat? How many flights a day are there to the rig? What size helicopters will you be using? How many boats will be assisting the rig? A boat with drill pipe, a standby boat, a crew boat? Will these boats support only the rig or other platforms that the company owns nearby? What size boats will you be using, a small 120 foot work boat, 180 foot work boat,250 foot plus work boat? How far to the boat dock is the rig location? Do they use two different boat docks?How many trips to the boat docks will the boats make? Knowing a drilling rig that will be at least one every day or every other day. Cranes, are they hydraulic diesel powered or electric? Burns a lot less diesel if the cranes are hydraulic. Rig burns X amount of diesel per day to run. Did you get stuck in the hole? How many days? Each day of not drilling adds another day of burning diesel for the rig? How many contract companies will you have on board where their equipment runs on diesel. Those roustabouts better keep everyone's units filled up or there will be hell to pay with the tool pusher if a contractor that's charging 10 grand a day for tools and equipment goes down due to his equipment ran out of diesel. Is there a forklift in the sack room? That burns diesel. This is a small taste and all we are looking at is the amount of liquid diesel being burned.
I didn't even get into trucking.You want to know about JIT delivery? The oilfield takes it to a whole new level. Get call at 7pm from rig "unit down need another one boat leaves the dock at midnight" call trucking company " got a load and go from Broussard to Fourchon need a drop deck load weight 25,000lbs needs to be there for midnight" meet the truck at the shop open up load him up and get him on the run,close shop and go home. That's how trucking is done in the oilfield. When you need to ship something you call a truck and put it on the road about 1 to 2 hours after you called them 24/7 365.
You try and figure that up for an industry as a whole to get a eroei for oil production. You can't, each well is different from the next it is NEVER the same and I didn't even touch production.Then as you said it's over
assumed production that in it's self can change. You can never truly know until you plug and abandon, never to get another drop from there again.
You ask about the energy going into piping and casing and other such. That also changes. If you drill a well with a 20 year old rig that has drilled 100's of wells it's eroei will be different from a brand new rig drilling it's first well. Same is said for all equipment from contract companies. The equipment's eroei is always changing depending on how many wells it is used on.
It's a lot different than farmer brown used x amount of diesel and x amount fertilizer and x amount of electricity to produce x amount of biofuel this harvesting season.