One embodiment of the method includes providing an electrically conductive first member in a wellbore located in a subsurface formation, and also providing an electrically conductive second member in the wellbore. The method also includes providing an electrically conductive granular material in the wellbore. The granular material is positioned so as to provide an electrical connection between the first member and the second member. An electrical current is established across the first member, the granular material and the second member so as to generate resistive heat within the granular material. The surrounding subsurface formation is thereby conductively heated so as to cause formation hydrocarbons in the formation to be heated, and in some cases, pyrolyzed to form hydrocarbon fluids. Preferably, the subsurface formation is an organic-rich rock formation, including, for example, an oil shale formation.