The Rising Influence of Rising Affluence

[OakesCS]

I did not imply that chemistry was the only problem but costs associated with chemistry are substantial. You will have a hard time explaining all the surface hardware if the problem is just about injecting steam.

In order to get heat into the reservoir there must be a source of water and that water is not obtained as pure H2O. Dirty water must have all the dissolved and suspended stuff removed before it goes into a boiler. Some other things may be added to prevent corrosion or scaling from solutes that the cleaning process failed to remove. Those additives may decompose in the steam and now there is steam plus other volatile compounds (things like ammonia). The steam with other stuff then gets injected and the heat from the steam is transferred to the bitumen as well as the sediment that hosts the bitumen (and possibly pore brine). The bitumen, sediment and pore brine are NOT inert to the steam and other stuff in it.

The bitumen and sediment are at about 30 C prior to steam injection and they've been stewing at that temperature for a few million years. Bacteria have used some of the oil as food and in the process they produce things like carboxylic acids and disulfides which may behave poorly upon steam injection. Biochemistry.

When steam is injected that multi-million year old karma is disturbed. I call that karma 'equilibrium'. It involves chemistry. The system now tries to achieve a new karma. Those changes involve changes in density and chemical composition. More chemistry. Organic sulfides may decompose and produce H2S and thiols. Those are expensive substances to deal with when they come out of the wells. Some of the thiols and other sulfides stay dissolved in the oil. Those must be removed and they end up as giant yellow mountains. Both processes involve chemistry.

Interactions between the steam, stuff in the steam, rock, and oil may lead to polymerization reactions which cause deleterious changes in viscosity or precipitation of asphaltenes which clog up pore throats. The carboxylic acids may make soaps or emulsions which can create production and processing problems. More chemistry.

Those same interactions also dissolve compounds from the rock and oil which partition into the aqueous liquid which condenses from the steam. When that condensed water, which is still toasty, is produced it can corrode the metal bits of the well and and surface plumbing or it may precipitate in those pipes and heat exchangers. All chemical problems.

Since water can be scarce and its use is highly regulated, the oil company tries to reuse the produced water but since it now contains a lot of stuff besides H2O, that extra stuff has to be removed before it goes back to the boilers. Lots of emulsion and surface chemistry as well as removing dissolved silica, and organic- and inorganic-salts.

In addition, there are suspended sediments in the oil and water that need to be removed and those sediments can be loaded with toxic, to both humans and refineries, transition metals that came from the non-inert oil interacting with the steam. More chemistry.

If you don't want to believe me, even though this is my profession, you can take a look at these:
http://sagd.wikispaces.com/Fouling+Concerns+in+SAGD

http://www.huskyenergy.com/downloads/InvestorRelations/Presentations/Oil-Sands-Water-De-Oiling-2011.pdf

http://www.nalco.com/documents/Published-Articles/R-1014_-_Scale_and_Deposit_Formation_in_SAGD_Facilities.pdf

There is a hell of a lot more than just worrying about getting steam into the reservoir.