The composition of acid/oil interface in acid oil emulsions

Petroleum Science

Tatiana N. Yusupova¹  Vladimir I. Morozov¹  Alina Kh. Valiullova¹  Yulia M. Ganeeva¹  Ekaterina S. Okhotnikova¹  Ekaterina E. Barskaya¹  Lucia F. Davletshina² 

[1] Arbuzov Institute of Organic and Physical Chemistry, FRC Kazan Scientific Center, Russian Academy of Sciences, Arbuzov str. 8, 420088, Kazan, Russian Federation;Gubkin Russian State University of Oil and Gas (National Research University), Leninsky Prospekt 65, 119991, Moscow, Russian Federation;

关键词: Acid emulsions;    Ferric cations;    Acid/oil interface;    Asphaltenes;    Resins;    Waxes;    Oil paramagnetic particles;    Fe(III)-based complexes;   

DOI  :  10.1007/s12182-020-00447-9

来源: Springer

【 摘 要 】

In well stimulation treatments using hydrochloric acid, undesirable water-in-oil emulsion and acid sludge may produce and then cause operational problems in oil field development. The processes intensify in the presence of Fe(III), which are from the corroded surfaces of field equipment and/or iron-bearing minerals of the oil reservoir. In order to understand the reasons of the stability of acid emulsions, acid emulsions were prepared by mixing crude oil emulsion with 15% hydrochloric acid solutions with and without Fe(III) and then separated into free and upper (water free) and intermediate (with water) layers. It is assumed that the oil phase of the free and upper layers contains the compounds which do not participate in the formation of acid emulsions, and the oil phase of the intermediate layers contains components involved in the formation of oil/acid interface. The composition of the oil phase of each layer of the emulsions was studied. It is found that the asphaltenes with a high content of sulfur, oxygen and metals as well the flocculated material of protonated non-polar oil components are concentrated at the oil/acid interface. In addition to the above, in the presence of Fe(III) the Fe(III)-based complexes with polar groups of asphaltenes are formed at the acid/oil interface, contributing to the formation of armor films which enhance the emulsion stability.

【 授权许可】

CC BY