??????????????????б?????о?

鄂尔多斯盆地苏里格气田是我国陆上发现的较大气田之一 ,目前对该气田分析的 5口气井的气油比为 15 .9× 10 4～ 98.9× 10 4m3 /m3 ,是个湿气田或干气田 ,然而初步的实验研究结论恰恰相反 ,该气田确是一个凝析气田。气藏类型经验判断表明 ,该气田可能是“常规干气田” ,也可能是“无油环凝析气田” ,处于干气藏和凝析气藏的过度带 ,没有统一的结论。相态实验研究表明 ,该气田为特低含凝析油的凝析气田。实验还发现 ,退泵降压观测到的露点压力与进泵升压观测到的雾和油花消失的压力不相同 ,后者大于前者 ,而且相差很大 ,说明该气田凝析油一旦析出 ,就较难气化。气油比改变露点压力也相应改变 ,气油比升高 ,露点压力降低 ,说明高气油比井的气含量大、油含量少 ,使油完全溶解在气中的压力就低。定容衰竭预测结果表明 ,该气田的反凝析油量很低 ,但是如果气井在井底压力低于露点压力下经过长时间生产 ,井底周围地层中仍然会有凝析油聚集 ,造成反凝析油动态污染

Experimental Research for Discriminating the Type of Gas Reservoir in Sulige Field

??Sulige gas field in E'erduosi Basin is one of the larger land gas fields found in China and it is considered as a wet gas field or dry gas field because the gas oil ratios of five gas wells used for analyzing this field currently are changed from 159×10³ to 989×10³m³/m³.However,the primary conclusion of experimental research is on the contrary:it is a condensate gas field.As judged by experience,the gas field may be a "conventional dry gas field" or may be also a "condensate gas field having no oil ring" and the gas reservoir in it is located in the transitional zone from dry gas reservoir to condensate gas reservoir.There is no unified conclusion.Through the experimental research on phase state,it was indicated that this gas field is a condensate gas field bearing extra low condensate.It was also found by experiment that the dewpoint pressure observed during pressure relief by backward pumping was different from the fog and oil bloom disappearing pressure observed during pressure boost by forward pumping and the latter was much larger than the former,which indicates that the condensate in the gas field is difficult to be gasified once it is liberated.When the gas oil ratio was changed,the dewpoint pressure would be relevantly changed,and while the gas oil ratio increased,the dewpoint pressure decreased,which shows that the well with high gas oil ratio contains large gas and a little oil,so the pressure of causing oil to be fully dissolved into gas is low.The constant volume depletion prediction result indicates that the retrograde gas condensate volume in the field will be small.If a gas well,however,will have been put into production at the bottomhole pressure lower than dewpoint pressure for a time,the condensate accumulation will be still found in the formation around the bottomhole,thus causing a retrograde gas condensate dynamic pollution.