Patent ID: 11953490
Assignee: EXXONMOBIL TECHNOLOGY AND ENGINEERING COMPANY
Field: Measurement (Instruments)
Classification: CPC G | IPC G

Claim 0:
1. A method comprising:
measuring a concentration of oleanane (O), C29 30-nor-neohopane (H29Ts), bicadalenes and methyl-bicadalenes (B), and C27 22,29,30-tris-nor-neohopane (Ts) in a hydrocarbon sample obtained from a subsurface location;
calculating an angiosperm index-1=[O]/([O]+[H29Ts]) and an angiosperm index-2=[O]+[B]/([O]+[B]+[Ts]);
estimating an age of the hydrocarbon sample based on a relationship between hydrocarbon age and the angiosperm index-1 and the angiosperm index-2;
using the relationship between the hydrocarbon age and the angiosperm index-1 and the angiosperm index-2 to determine a location from which to extract hydrocarbons from the subsurface location; and
extracting the hydrocarbons from the determined subsurface location;
wherein the relationship is determined by measuring the angiosperm index-1 and the angiosperm index-2 of multiple reference hydrocarbon samples having known ages and correlating the measured angiosperm indices-1 and the measured angiosperm indices-2 against the known ages of the multiple reference hydrocarbon samples.