Patent ID: 7635023

Claim:
A method for treating a hydrocarbon containing formation, comprising: providing heat for a first amount of time to a first hydrocarbon layer in the formation from a first heater located in an opening in the formation, the opening and the first heater having a substantially horizontal or inclined portion located in the first hydrocarbon layer in the formation and at least one connecting portion extending between the substantially horizontal or inclined portion and the surface; removing at least one connecting portion of the first heater from the opening; placing an isolation material in the opening such that the isolation material at least partially isolates the layer in which the substantially horizontal or inclined portion of the first heater is located; forming an additional substantially horizontal or inclined opening portion in a second hydrocarbon layer, the additional portion extending from at least one of the connecting portions of the opening; placing a second heater in the additional substantially horizontal opening portion; and providing heat from the second heater to the second hydrocarbon layer.