Patent ID: 8641150

Claim:
An in situ method of recovering natural resources, comprising: (a) heating the organic-rich rock formation in situ, the organic-rich rock formation (i) containing formation hydrocarbons, and (ii) containing one or more formation water-soluble minerals, the heating (i) pyrolyzing at least a portion of the formation hydrocarbons to create hydrocarbon fluids, and (ii) generating water which migrates and at least partially dissolves the one or more formation water-soluble minerals in situ to form a first aqueous fluid (b) producing a production fluid from the organic-rich rock formation, the production fluid containing the hydrocarbon fluids and the first aqueous fluid; (c) separating the production fluid into a hydrocarbon stream and a first aqueous stream at a surface facility; (d) recovering a first water-soluble mineral from the first aqueous stream; (e) monitoring for the presence of CO 2 in the production fluid; (f) determining the isotopic composition of the CO 2 ; and (g) estimating the fraction of the CO 2 produced from organic versus inorganic sources.