高效开发深层轻质油气藏的途径

深层常蕴藏丰富的轻质油、凝析气及天然气,构成经济价值很高的特殊油、气田。高温高压下,液态烃溶解于气态烃中,开采时压力降到露点压力后储层流体出现反凝析现象,致使油层内残留反凝析油,为此国外为高效开发轻质油藏而采用注氮气混相驱以提高凝析油、气藏的地层压力,获取较高的采收率。 混相驱替存在两种类型,其中的多次接触混相驱又称动力混相驱,它是通过多次蒸发或萃取完成的。本文举出美国福多奇(Fordoche) 油田注氮混相驱实例,预计最终采收率可达54.5％;最后,为开发好凝析气田及挥发性油田提出几点做法。

METHODS OF DEVELOPING DEEPLY BERRIED LIGHT OIL AND GAS RESERVOIRS WITH HIGH EFFECIENCY

In deep formation light oil. condensed gas and natural gas are often berried，forming special oil and gas reservoirs of high economic value. Under high pressure and high temperature, liquid hydrocarbon is disolved in gaseous hydrocarbon. When pressure drops below bubble point, the retrograde condensation phenominon occurs in reservoir fluid，resulting in gas retrograde condensate remaining in the reservoir. Therefore,the miscible nitrogen injection is practiced abroad for effectively developing light oil reservoirs. With the pressure increased in condensate reservoirs. high recovery is obtained. There are two kinds of miscible displacement. One of them is multi plecontact miscible displacement, being also called dynamic miscible displacement. which is completed by multiple distillation and extract. The example of miscible nitrogen injection in Fordoche oil field, U. S, A. is given in this paper . the predicted ultimate recovery is as high as 54.5%. Finally， some suggestions are made on the effective development of condensate gas and volatile oil fields.