| CPC E21B 41/0035 (2013.01) [E21B 43/305 (2013.01)] | 8 Claims |

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1. A method of drilling naturally fractured geothermal reservoirs, comprising:
drilling a vertical pilot well in a formation comprising a geothermal heat reservoir;
obtaining data on the properties of the formation, wherein the properties are derived from core or electric logs, wherein the data comprises temperature data on the formation;
determining the direction and depth of a potential horizontal lateral;
determining the orientations of fractures in the formation;
drilling a managed pressure horizontal lateral until one of the fractures is encountered;
employing underbalanced drilling for the managed pressure horizontal lateral, wherein the pressure exerted by the effective circulating density is lower than a rock pore pressure when drilling through porous rock, and further wherein the pressure exerted by the effective circulating density is lower than a borehole stability pressure when drilling through non-porous impermeable rock;
running one or more cementing sleeves into the managed pressure horizontal lateral;
isolating a rock interval with cement by inserting cement in the annulus of the managed pressure horizontal lateral between two cementing sleeves;
stimulating one or more conduits; and
producing from the vertical pilot well.
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