US 12,379,364 B2
Method for determining the composition of water in low BSW oils
Iris Medeiros Junior, Rio de Janeiro (BR); Ricardo Augusto Pereira De Avila, Rio de Janeiro (BR); Rogerio Mesquita De Carvalho, Rio de Janeiro (BR); Rainerio Escalfoni Junior, Rio de Janeiro (BR); Ana Gabriela Apolonio De Souza, Rio de Janeiro (BR); Oto Leonardo Reis Gomes, Rio de Janeiro (BR); Roberta De Moraes Maciel, Rio de Janeiro (BR); Alessandra Rangel Cassella, Rio de Janeiro (BR); Elisangela Fragoso Reis Da Rocha, Rio de Janeiro (BR); Maria Marta Moreira Crelier, Rio de Janiero (BR); Bruno Charles Do Couto, Rio de Janeiro (BR); and Thiago Andrade Delfino Da Silva, Rio de Janeiro (BR)
Assigned to Petróleo Brasileiro S.A.—Petrobras, Rio de Janeiro (BR)
Filed by Petróleo Brasileiro S.A.—Petrobras, Rio de Janeiro (BR)
Filed on Nov. 14, 2022, as Appl. No. 17/986,580.
Claims priority of application No. 10 2021 022892 0 (BR), filed on Nov. 12, 2021.
Prior Publication US 2023/0152295 A1, May 18, 2023
Int. Cl. G01N 33/28 (2006.01)
CPC G01N 33/2847 (2013.01) 6 Claims
OG exemplary drawing
 
1. A method for determining the composition of water in oils with basic sediment in water (BSW) below 0.5%, characterized in that it comprises the following steps:
(a) Homogenizing oil samples for at least 30 minutes;
(b) Filtering the oil samples using a system for pumping under pressure using peristaltic pumps or “pan” system pressurized with N2, under heating at a temperature between 40° C. and 60° C.;
(c) Determining the water content in the oil samples by volumetric Karl Fischer titration;
(d) Determining the metals in the oil samples by means of incineration, in which the ashes obtained are mineralized, where the solution obtained is analyzed by the techniques of AAS or ICP-AES; and for the determination of metals in integrated water, the aqueous sample is filtered, diluted between 10 and 20 times, and then this solution is analyzed by ICP-OES;
(e) Determining the total chlorine content directly in the oil samples using monochromatic wavelength scattering X-ray fluorescence spectroscopy (MWDFRX);
(f) Performing liquid-liquid extraction with 100 grams of oil sample by adding 5 grams of distilled water, homogenizing the mixture for 2 hours, then adding a demulsifier, and perform a new homogenization for another 5 minutes; then, pouring the oil with the separated water into a separating funnel to obtain the water;
(g) Determining the chloride content directly in integrated water or in the aqueous extract by potentiometric titration;
(h) Determining the alkalinity directly in the aqueous extract by titration with acidic solution;
(i) Performing liquid-liquid extraction for tracer evaluation through 500 mL of oil added to 175 mL of toluene, 50 mL of saline solution (35 g/100 mL) and 10 drops of demulsifier, homogenizing the mixture in a mechanical stirrer for 30 minutes and then subjecting to centrifugation for two hours at 40° C. under rotation of 11000 rpm;
(j) Performing the analysis of tracers in the aqueous phase obtained in step (i) using extraction by SPE acidification and derivatization to qualify the presence by gas chromatography coupled to high resolution mass spectrometry (GC/HR-MS) or gas chromatography coupled to triple quadrupole mass spectrometry.