Laboratory Study of the Effect of Inhibitors on Asphaltene Adsorption on the Reservoir Rock by Experimental Design Method

One of the major problems in the oil industry is asphaltene adsorption on various surfaces, including the surface of the reservoir rock. The adsorption of asphaltene on the surface of the reservoir›s rock causes wettability change, blockage of cavities and, consequently, reduction of crude oil production. In this study, the addition of inhibitor as an agent to reduce the adsorption of asphaltene has been used. To observe this effect, two inhibitors of coconut diethanol amide and dodecyl benzene sulfonic acid have been used. For statistical analysis and optimization of experiments, Design Expert software and D-Optimal surface design were used. The model results have high creditworthiness. The test design factors included the initial asphaltene formation in the range of 3000-1000 mg.L1-, the weight ratio of asphaltene to the inhibitor 1: 1, 1: 2, 1: 3 and 1: 0 (without inhibitors) and two types inhibitor include Coconut diethanol amide and dodecyl benzyl benzene sulfonic acid. According to the results of the software output, has a 1:2 ratio of the least amount of asphaltene adsorption. Coconut diethanol amide inhibitor also has the greatest effect on reducing asphaltene adsorption. The adsorption range of asphaltene in the absence of an inhibitor is within the range of the initial concentration of asphaltenes between 63/13 and 83/5 mg.g1-, and the addition of inhibitor in the best case can reduce up to 35% adsorption of asphaltenes.