库车油气系统油气藏相态分布及其控制因素

根据库车油气系统80个油气藏地层流体的高温高压实验(PVT)结果和油气藏的油气物理和化学性质,可以清晰地认识该系统已发现油气藏的流体相态类型和分布特征,并可以比较深入地了解其主要的控制因素。库车油气系统为富气的地质单元,烃流体以气态烃为主,液态烃处于次要地位。库车油气系统的北带是干气和湿气集中分布的地带,并有少量凝析气藏,这些凝析气藏贫含凝析油;南带是以富―特富凝析气藏为主的地带,并有伴生油藏和挥发性油藏分布。库车油气系统的西段比较富油,油藏和富―特富凝析气藏比较集中的出现在西段的羊塔克地区、却勒地区和乌什地区。认为库车油气系统烃类成藏史的特点是:1早期是以富油的凝析气和正常原油成藏为主,主要成藏区分布在早期圈闭发育的南带;2晚期是干气、湿气和贫凝析气的充注和成藏时期,在北带晚期圈闭中形成了干气藏、湿气藏和贫凝析油的气藏,在南带晚期同样也有较干的天然气进入早期油气藏,并使南带早期油气藏中的烃体系发生混合和分异。

THE DISTRIBUTION AND CONTROL FACTORS OF PHASE STATE OF OIL AND GAS POOLS IN KUQA PETROLEUM SYSTEM

The phase state and distribution rule could recognized clearly and its control factors could investigation, as a means of the PVT experimental data of 80 layers and the physical and chemical characters of these hydrocarbons produced from oil and gas pools in Kuqa petroleum system. The main type was gaseity and subordinative type was liquid in hydrocarbon fluid system in this system. The system divided two or three belts-south, middle and north, and two segments-east and west, and the north belt was rich in gas pools, including dry gas pools and wet gas pools as will as poor condensate gas pools, and the south belt contained more abundant condensate gas pools with fewness partner oil pools and volatilty oil pools. However the west segment of whole system contained more superabundant and abundant condensate gas pools and oil pools in this system, for example the Yangtake, Qule and Wush(Yilake) regions concentrated abundant condensate gas pools and oil pools. It would be characteristic of history of forming-pool of the early stage accumulated normal oil and abundant condensate gas on south belt in main, late stage accumulated dry gas, wet gas and pool condensate gas on north belt in main. Naturalness more dryer gas generated during late stage would charged into the early pools, and the hydrocarbon fluid system in these pools changed them phase state owing to them component admixed each other. Of course the early traps profited forming abundant condensate gas pools and oil pools, whereas the late traps were prone to form more dryer gas pools. So the traps surrounding early uplift and on early uplift were prone to form normal oil and abundant condensate gas. Special most lithologic traps formed early stage and could be finded more rich-oil pools.