Self-generating heat process for in-situ conversion of medium-low mature and organic-rich shale

Abstract

The present disclosure provides a self-generating heat process for in-situ converting medium-low mature and organic-rich shale, and relates to the field of in-situ mining of medium-low mature shale rich in organic matter, the self-generating heat process mainly comprises the following steps: locally preheating the vincinity of an injection well of medium-low mature and organic-rich shale formation with well-reformed reservoir and injecting ambient temperature air into the preheated formation to excite and establish a chemical reaction zone composed of a residue zone, an autogenous heat zone, a thermal cracking zone and a preheating zone. Heat is released by oxidation reaction of residues generated after kerogen thermal cracking, so as to realize convection heating of medium-low mature and organic-rich shale formation. Oil and gas products generated from kerogen thermal cracking enter production wells through fractures and are lifted to the ground surface. Because the in-situ oil shale conversion technology only needs local preheating the vincinity of the injection well and only a small amount of external heat or combustibles injection, the related cost is low.