نوع مقاله : مقاله پژوهشی
نویسندگان
1 بخش مهندسی نفت، دانشکده مهندسی شیمی نفت و گاز ، دانشگاه شیراز، شیراز ، ایران
2 بخش مهندسی نفت، دانشکده مهندسی شیمی نفت و گاز، دانشگاه شیراز، شیراز، ایران
3 بخش مهندسی نفت، دانشکده مهندسی شیمی نفت و گاز، دانشگاه شیراز، شیراز ، ایران
4 شرکت ملی مناطق نفتخیز جنوب ، اهواز ، ایران
چکیده
کلیدواژه‌ها
موضوعات
عنوان مقاله [English]
نویسندگان [English]
Produced water along with oil is one of the biggest wastewater produced by industries. Among the methods of managing this water is re-injecting it into oil reservoirs to increase pressure; On the other hand, due to the presence of various pollutants, there is a possibility of damage to the formation. In the meantime, the presence of oil droplets along with this water is one of the important structural damages that causes clogging of the porous medium, reducing the injectability and increasing the injection pressure. In this research, synthetically produced water containing oil droplets emulsified in water was made, and through microscopic investigations and conducting micromodel tests, the effect of the amount of oil concentration on the size of the emulsion droplets and also the amount of porosity reduction was investigated. In the microscopic tests, the oil concentration and salinity ranged from 30 to 100 drops and 4 ppm to 32 ppm, respectively, and the oil concentration was 70 and 150 drops to inject up to PV 35. The results of microscopic observations showed that the increase in oil concentration caused an increase in the size of oil droplets so increasing the oil concentration from 30 to 100 drops increases the average droplet size from 1.56 to 1.98 micrometers. In the micromodel tests, by calculating the occupied porosity caused by the trapped oil droplets, it was found that the ratio of the final occupied porosity to the initial porosity decreases with the increase of two factors, the injection volume and the oil concentration. As an example, for an oil-in-water emulsion with a concentration of 150 drops of oil, in the injection volume of PV 7 and PV 35, this ratio reaches from 0.875 to 0.642 in the injection volume. Also, by injecting PV 35 synthetic production water with two concentrations of 70 and 150 drops of oil, the porosity reduction ratio reached 0.914 to 0.642, which confirms the formation damage. The findings of this research show, quantitatively, the importance of removing the pollutant of oil droplets along with the produced water (before injecting them into the wells) to prevent the decrease of injectivity.
کلیدواژه‌ها [English]
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