A method for enhanced production of hydrocarbon fluids from an organic-rich rock formation such as an oil shale formation is provided. The method generally includes completing at least one heater well in the organic-rich rock formation, and also completing a production well in the organic-rich rock formation. The method also includes the steps of hydraulically fracturing the organic-rich rock formation from the production well such that one or more artificial fractures are formed, and heating the organic-rich rock formation from the at least one heater well, thereby pyrolyzing at least a portion of the organic-rich rock into hydrocarbon fluids Pyrolyzing the organic-rich rock formation creates thermal fractures in the formation due to thermal stresses created by heating. The thermal fractures intersect the artificial fractures. As an additional step, hydrocarbon fluids may be produced from the production well. Preferably, the organic-rich rock formation is an oil shale formation.