US 12,013,387 B2
Determining reservoir fluid composition to pentatetracontanes plus
Daryl Sean Sequeira, Dhahran (SA); Ahmed M. Sahl, Dammam (SA); and Okechukwu M. Egbukole, Al-Khobar (SA)
Assigned to Saudi Arabian Oil Company, Dhahran (SA)
Filed by Saudi Arabian Oil Company, Dhahran (SA)
Filed on Mar. 11, 2021, as Appl. No. 17/198,535.
Prior Publication US 2022/0290560 A1, Sep. 15, 2022
Int. Cl. G01N 33/28 (2006.01); G01N 30/68 (2006.01); G01N 30/86 (2006.01); G01N 30/02 (2006.01); G01N 30/06 (2006.01); G01N 30/88 (2006.01)
CPC G01N 33/2823 (2013.01) [G01N 30/68 (2013.01); G01N 30/8665 (2013.01); G01N 2030/025 (2013.01); G01N 2030/062 (2013.01); G01N 2030/8854 (2013.01)] 9 Claims
OG exemplary drawing
 
1. A method for determining a composition of a fluid from a reservoir, comprising:
collecting a sample of the fluid from the reservoir in a sample container;
pressurizing the sample container to form the single-phase fluid;
heating the sample container to about 100° C.;
pumping the single-phase fluid from the sample container into a flashing container;
depressurizing the single-phase fluid during pumping forming a gas phase and a liquid phase;
capturing the liquid phase in the flashing container;
capturing the gas phase in a flash gas cylinder;
recirculating a portion of the gas phase through the liquid phase until equilibrium is reached between the gas phase and the liquid phase;
recording a volume of the gas phase;
determining a weight of the liquid phase;
determining an atmospheric gas-oil ratio (GOR) from the volume of the gas phase and the weight of the liquid phase;
determining composition of the gas phase to C9+;
measuring density of the liquid phase;
determining molecular weight of the liquid phase;
determining composition of the liquid phase to C45+; and
calculating the total hydrocarbon composition of the fluid from:
the volume of the gas phase;
the weight of the liquid phase;
the composition of the gas phase;
the composition of the liquid phase; and
the atmospheric GOR.