Abstract: Methods and systems of treating an oil shale formation using an in situ thermal process are described herein. A method of treating an oil shale formation in situ includes providing heat from one or more heat sources to at least a portion of the formation; allowing the heat to transfer from at least the portion to a selected section of the formation substantially by conduction of heat; pyrolyzing at least some hydrocarbons within the selected section of the formation; and producing a mixture from the formation.

Abstract: A method for heat injection into a subterranean formation is provided. The method utilizes flameless combustion and a gas fired heater having an electrical heated surface for ignition of the gas. The absence of a flame eliminates the flame as a radiant heat source and results in a more even temperature distribution throughout the length of the burner. Flameless combustion is accomplished by preheating the fuel and the combustion air to a temperature above the autoignition temperature of the mixture. Preheating hydrocarbon fuel requires the inclusion of a carbon formation suppressant such as carbon dioxide or steam to prevent carbon formation.

Abstract: A cement slurry is provided which is useful to cement wellbores in high temperature service. A high alumina cement is used. The density of the slurry is relatively low as a result of using a low density aggregate. In a preferred embodiment, the low density aggregate is graphite. The graphite additionally imparts a significantly improved thermal and electrical conductivity to the hardened cement.