Successful approach to mitigate the asphaltenes precipitation problems in ESP oil wells

Abstract

AbstractThis study introduces a comprehensive and cost-effective approach to diagnose and treat the asphaltenes precipitation problems in different downhole conditions. The proposed approach has been successfully applied in two oil wells (Well-I, and Well-II) located in the Western Desert of Egypt. The two wells produce oil of moderate to high oil gravity with low asphaltenes content using Electrical Submersible Pumps (ESP). In such operating conditions, solid deposits caused blockage at the pump intake and within the pumping stages in the two wells. This blockage led to a sharp decrease in oil production rate and a significant increase in the operating cost. The existing failure analysis procedure was not able to accurately identify the reasons for the blockage; accordingly, the treatment operations were unsuccessful. On the contrary, applying the proposed approach accurately (1) identified the type of the solid deposits, (2) solved the problem using proper treatment option with minimum cost, and (3) improved the oil production rate. The laboratory tests of the fluid and solid deposits showed that (1) the asphaltenes were unstable in the crude oil and acted as a glue for other minerals, and (2) the blockage was successfully diagnosed to confirm that the two wells had asphaltenes precipitation problem. The laboratory tests were extended to select optimum asphaltene dispersant for wells treatments. The field application results showed a significant increase in the oil production rate from 700 to 1600 STB/D in Well-I and from 470 to 1500 STB/D in Well-II. Moreover, the operating cost decreased considerably from 2.01 to 0.43 $/STB in Well-I, and from 4.37 to 0.52 $/STB in Well-II after applying the proposed approach.