Patent ID: 7584789

Claim:
A method for producing hydrocarbons, comprising: providing heat from one or more heaters to a subsurface formation to heat at least a portion of the formation; producing formation fluid from a portion of the subsurface formation; separating the formation fluid to produce a liquid stream; catalytically cracking at least a portion of the liquid stream in a first catalytic cracking system by contacting the liquid stream with a catalytic cracking catalyst to produce a crude product stream and a spent catalytic cracking catalyst; regenerating at least a portion of the spent catalytic cracking catalyst to produce a regenerated cracking catalyst; catalytically cracking a stream comprising gasoline hydrocarbons in a second catalytic cracking system by contacting the stream comprising gasoline hydrocarbons with at least a portion of the regenerated catalytic cracking catalyst to produce a second crude product stream, the second crude product stream comprising a used regenerated cracking catalyst and hydrocarbons having a carbon number of at least 2, wherein at least 30% by weight of the hydrocarbons having a carbon number of at least 2 are olefins; separating at least some olefins from the second crude product stream, wherein the separated olefins have carbon numbers from 2 to 5; and providing at least a portion of the used regenerated cracking catalyst from the second catalytic cracking system to the first catalytic cracking system.