Geopreater heating method and apparatus

A method for producing a pipeline transportable product stream from a combustible feed stream, said method comprising:

• a. flowing said feed stream downwardly through an indirect subterranean heat exchanger and transferring heat from said product stream to said feed stream;
• b. heating said feed stream by an energy source other than said product stream and an oxidizing reaction, wherein at least part of said heating is accomplished in conjunction within said heat exchanger;
• and
• c. reacting said heated feed stream with an oxidizer stream near the bottom of said heat exchanger.

A method for upgrading a crude oil feed to product a lower viscosity oil product, said method comprising:

• a. introducing said feed into a well having a generally closed bottom, and flowing said feed towards said bottom;
• b. exchanging heat from the product to the feed in a heat exchanger;
• c. additionally heating said feed using a non-combustion source of heat, wherein said additional heating is at least in part accomplished during said exchanging heat step;
• and
• d. mixing and at least partially reacting said at least partially heated feed with a quantity of an oxidizer near said bottom capable of upgrading the feed to said lower viscosity product.

In a method for upgrading a combustible, viscous feed to product a lower viscosity product, said method using an oxidizing fluid and a subterranean cavity having a generally closed bottom, wherein said feed is:

• a. introduced into said cavity and flowed towards said bottom;
• b. first heated by said lower viscosity product in a heat exchanger within said cavity;
• and
• c. mixed and at least partially reacted with a quantity of said oxidizing fluid near said bottom sufficient to produce a reaction heat quantity and a reaction product quantity which upgrades said feed to said lower viscosity product, wherein the improvement comprises:
• second heating of said feed, said heating at least in part concurrent with said first heating and within said heat exchanger from a source other than an oxidizing reaction with said product stream;
• and
• reducing said quantity of said oxidizing fluid so as to reduce said reaction production quantity.