US 12,487,202 B2
Estimation of dielectric properties of a downhole fluid
Salah Mohammed Al-Ofi, Khobar (SA); Guodong Jin, Katy, TX (US); and Shouxiang Ma, Dhahran (SA)
Assigned to BAKER HUGHES OILFIELD OPERATIONS LLC, Houston, TX (US); and SAUDI ARABIAN OIL COMPANY, Dhahran (SA)
Filed by Baker Hughes Oilfield Operations LLC, Houston, TX (US); and Saudi Arabian Oil Company, Dhahran (SA)
Filed on Feb. 15, 2023, as Appl. No. 18/169,639.
Prior Publication US 2024/0272104 A1, Aug. 15, 2024
Int. Cl. G01N 27/02 (2006.01); E21B 49/08 (2006.01)
CPC G01N 27/026 (2013.01) [E21B 49/08 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A method of analyzing a downhole fluid, comprising:
performing measurements of a dielectric property of the downhole fluid, the downhole fluid including a mixture of a filtrate fluid circulated through a borehole and a connate fluid originating in a subterranean region proximate to the borehole, the filtrate fluid having a known value of a dielectric property, the downhole fluid having an initial value of a volume ratio corresponding to a ratio of a volume of the filtrate fluid to the volume of the downhole fluid,
wherein the measurements include a first measurement of the downhole fluid, and one or more additional measurements, each additional measurement performed after an amount of the filtrate fluid is injected into the downhole fluid to change the volume ratio, each additional measurement performed when the downhole fluid has a different volume ratio;
acquiring a plurality of reference profiles, each reference profile acquired by at least one of measuring the dielectric property of a respective reference mixture and estimating the dielectric property by a mathematical model, the respective reference mixture including a first fluid and a reference fluid, the first fluid having the known value of the dielectric property, each reference profile representing a change in the dielectric property of the respective reference mixture as a function of a change in a volume ratio of the respective reference mixture; and
comparing the measurements to each reference profile, wherein the comparing includes calculating a measurement profile from the measurements based on incremental volume ratio changes between each of the first measurement and the one or more additional measurements, and estimating a value of the dielectric property of the connate fluid based on the comparing.