Studying efficiency of various chemicals for hydrogen sulfide and low-molecular-weight mercaptan removal from oil and water during well stimulation

UDK: 622.276.8:665.622

DOI: 10.24887/0028-2448-2026-7-67-71

Key words: study, oil, hydrogen sulfide, mercaptans, oxidizer, produced water, efficiency

Authors: V.V. Soloviev (TatNIPIneft, RF, Almetyevsk); А.N. Shatalov (TatNIPIneft, RF, Almetyevsk); R.Z. Sakhabutdinov (TatNIPIneft, RF, Almetyevsk); А.Z. Mingazova (TatNIPIneft, RF, Almetyevsk); Т.V. Ibryaeva (TatNIPIneft, RF, Almetyevsk); D.N. Morunova (TatNIPIneft, RF, Almetyevsk); D.D. Shipilov (TatNIPIneft, RF, Almetyevsk); D.Yu. Gavrilov (TatNIPIneft, RF, Almetyevsk

The study is focused on the efficiency of chemical agents for hydrogen sulfide and mercaptans removal from the wellstream. The aim of the study is to establish a field-applicable procedure for hydrogen sulfide and mercaptans identification in crude oil and produced water, and to select an optimal chemical agent capable of neutralizing them in produced fluids by lowering their concentrations to 20 ppm and 40 ppm, respectively. When stimulating wells with formation fluids characterized by high hydrogen sulfide and mercaptan content, appropriate treatment techniques are applied to neutralize corrosive sulfur compounds, with determination of their concentrations as a prerequisite for ensuring safe delivery of the produced fluids to consumers. Accurate determination of hydrogen sulfide and mercaptan concentrations under the field conditions is challenging. To solve this problem, the measurement procedure № 62506-06 was tested using crude oil samples specifically for determination of the mercaptan content. Efficiency of the four samples of neutralizing agents and various oxidizers was analyzed. A relationship between hydrogen sulfide and mercaptan concentration and oil–neutralizer contact time was established. Performance of a neutralizer was evaluated during treatment of produced water and crude oil with water content of up to 5 %. The gas-liquid mixture can be disposed of in horizontal flares using different types of burners. However, crude oil flaring is prohibited during well testing, surveying, or stimulation operations. Consequently, identification of an optimum chemical agent for neutralization of hydrogen sulfide and light mercaptans in gas-liquid mixtures remains a crucial task.

References

1. MVI No. 62506-06. Neft’, nefteprodukty i uglevodorodnye gazovye kondensaty. Opredelenie serovodoroda (Oil, petroleum products, and hydrocarbon gas condensates. Determination of hydrogen sulfide), Bugul’ma: Publ. of TatNIPIneft’, 2006, 14 p.

2. Shipilov D.D., Shatalov A.N., Garifullin R.M., Solov’ev V.V., Hydrogen sulphide stripping technologies used at Tatneft’s assets (In Russ.), Neftyanaya provintsiya, 2020, No. 4, pp. 206–216, DOI: https://doi.org/10.25689/NP.2020.4.206-216

3. Ibragimov N.G., Shipilov D.D., Mingazova A.Z. et al., Application of hydrogen sulfide scavengers for oil treating at crude oil treatment facilities of Tatneft OAO

(In Russ.), Neftyanoe khozyaystvo = Oil Industry, 2014, No. 7, pp. 52–54.