سال انتشار: ۱۳۸۴

محل انتشار: چهارمین همایش ملی دانشجویی مهندسی نفت

تعداد صفحات: ۱۸

نویسنده(ها):

Seyyed Jafar Fathi – Iranian Central Oil Fields Company

چکیده:

The so-called Foamy Oil phenomenon is associated with primary cold production from heavey-oil reservoirs producing under solution- gas drive, A number of heavy oil solution gas drive reservoirs show anomalously good primary performance and high oil production rates. Examples are: Lindbergh, Frog Lake, Lloydminster, and Edam in Saskatchewan. The nature of gas dispersion in oil distinguishes foamy oil behavior from conventional heavy oil behavior. Moreover, the important issues that distinguish foamy oil from conventional heavy oil are: the amount of dispersed gas in oil, and the time for which gas bubbles remain dispersed in the oil. These reservoirs are characterized by slower decline in reservoir pressure, lower than expected GOR, higher critical gas saturation (35% to 40%), foamy produced crude oil, and higher ultimate recovery in primary production phase. Production fates from cold production wells can be many times higher than the rate predicted by Darcy equation which does not account for sand production and the foamy oil behavior. Several possible cause for the anomalous production behavior have been suggested by investigators. These include the formation of wormholes and cavities around the wellbore, sand dilation, enhancement of oil mobility by nucleation of large number of micro-bubbles, in-situ formation of oil continuous foam. Influx of bottom water, and non-Newtonian flow.