Practical Modification of Tannic Acid Polyether Demulsifier and Its Highly Efficient Demulsification for Water-in-Aging Crude Oil Emulsions

Abstract

In order to break the aging crude oil (WACO) emulsion of the offshore platform more effectively, a highly active isocyanate, polyaryl polymethylene isocyanate (PAPI), was selected to modify the pilot-scale tannic acid demulsifier. In the addition of PAPI, its molecular weight and viscosity dramatically increased, while its relative solubility, hydroxyl number, and cloud point exhibited an opposite direction, showing an increase in hydrophobicity. After adding the above modified demulsifier, a remarkably improved water removal of WACO emulsion accompanied by a notable reduction of the water content in the oil phase monitored by the Karl Fischer method was observed. Demulsification on the offshore platform demonstrated that the best water removal was achieved when the proportion of PAPI is 1.5 wt %. Its demulsification efficiency reached 95.7%, which was 25.6% higher than the 76.2% of unmodified demulsifier. In addition, a positive correlation between viscoelasticity of emulsion and demulsification performance was found by only adjusting the parameters of the rheometer. This method may be utilized to characterize the demulsification performance by any rotary rheometer. The pilot-scale demulsification experiment demonstrated that the water removal can reach 98.14 vol % and residual water content was only 0.55 vol %. These results further confirmed the excellent demulsification performance of the modified demulsifier toward the WACO emulsion in production.

Proanthocyanidin-Based Polyether Demulsifiers for the Treatment of Aging Oil Emulsions

“…The branch structure of the demulsifier is an important factor for demulsification. ,, The presence of such a structure increases the number of contact sites and the interfacial area occupied and facilitates the interaction between the demulsifier and the asphaltenes present at the oil–water interface. Additionally, aromatic rings improve the demulsification performance by increasing the affinity between the demulsifier and asphaltenes as revealed by Abdel-Azim et al Therefore, increasing both the number of branches and aromatic rings of demulsifier is an ideal choice to improve the demulsification performance toward aging oil emulsion as demonstrated in our previous works. , …”

“…Additionally, aromatic rings improve the demulsification performance by increasing the affinity between the demulsifier and asphaltenes as revealed by Abdel-Azim et al 14 Therefore, increasing both the number of branches and aromatic rings of demulsifier is an ideal choice to improve the demulsification performance toward aging oil emulsion as demonstrated in our previous works. 15,16 Natural chemicals have been introduced in the field of petroleum production for their environmentally benign and biodegradable benefits. 3,17−19 As a naturally condensed tannin, proanthocyanidin (PC) is a mixture of dimers, trimers, and tetramers (oligomeric proanthocyanidins) formed by the condensation of the flavan-3-ol monomer.…”

Technologies Involved in the Demulsification of Crude Oil

“…The optimum formulation of the demulsifier with a PDcE/CaCl2/CPAM ratio of 20:600 An ionic demulsifier at a concentration of 900 mg/L and resulted in a dewatering efficiency of 89.5 percent. Polymers, such as alkene oxides diester, ethicellul, formulated demulsifiers [19]. Variation at polymer demulsifier concentration has often led to different degrees of demulsification efficiency, and at 97.5 percent the highest demulsification effectiveness recorded with the help of a polyester-based demulsifyer within 45 minutes of the demulsification process.…”

The Influence of Newly Synthesized Demulsifiers on the Interfacial Rheological Properties of a Naturally Occurring Water/Oil Emulsion

“…When the demulsifier reduces the barrier strength and interfacial viscoelasticity to a certain level, the separation of water from the emulsion would be more easy. 21 , 22 …”