Patent ID: 11874258
Assignee: SAUDI ARABIAN OIL COMPANY
Field: Measurement (Instruments)
Classification: CPC G  B | IPC G

Claim 7:
8. A method for evaluating a crude oil sample and calculating an indicative property of a naphtha or gas oil fraction of the crude oil sample without first distilling said naphtha or gas oil fraction, the method comprising:
obtaining density of the crude oil sample;
subjecting said crude oil sample to gel permeation chromatography (GPC) analysis, and entering GPC peak intensity, full permeation time, retention time, and full exclusion time determined by the GPC analysis into non-volatile memory of a computer;
using a processor of the computer and enter into the non-volatile memory to calculate a GPC retention time index as a function of the full permeation time, retention time, and full exclusion time;
using the processor to convert the GPC retention time index to molecular weight, and to enter the molecular weight into the non-volatile memory;
using the processor to calculate and enter into the non-volatile memory a GPC index as the sum of the products of GPC peak intensity and molecular weight over a range of molecular weights;
and using the processor to calculate and enter into the non-volatile memory the indicative property for the naphtha or gas oil fraction of the crude oil from a two-variable polynomial equation with predetermined constant coefficients developed using linear regression techniques;
wherein the two variables of the two-variable polynomial equation are the GPC peak intensity and the density of the crude oil sample.