Methods for using isotopic signatures to determine characteristics of hydrocarbon sources

A method for determining where to drill a well in a hydrocarbon reservoir, comprising:

• providing a basin model of the hydrocarbon reservoir;
• obtaining a hydrocarbon fluid sample from the hydrocarbon reservoir;
• analyzing the hydrocarbon fluid sample to determine at least one measured clumped isotope signature or measured position specific isotope signature for at least one hydrocarbon species in the hydrocarbon fluid sample;
• determining at least one expected clumped isotope signature or expected position specific isotope signature, where the expected clumped isotope signature or expected position specific isotope signature is determined from a model that reflects different source compositions, isotopic structures, and kinetic processes associated with the hydrocarbon reservoir, and wherein the model is solved using a kinetic Monte Carlo simulation;
• comparing the measured clumped isotope signature or measured position specific isotope signature with the expected clumped isotope signature or expected position specific isotope signature;
• using the comparison to identify an expected source of the hydrocarbons in the basin model;
• and
• causing a well to be drilled to obtain hydrocarbon from the hydrocarbon reservoir.