洛带-新都遂宁组气藏流体地球化学特征

GEOCHEMISTRY CHARACTERISTICS OF FLUID FOR SUINING GAS POOL

遂宁组气藏以产天然气为主，含微量凝析油和混有地层水的凝析水，是一个无边水或底水的气藏。天然气组分中烃类气体含量超过98％，酸性气体含量极低，可以直接管输，是经济价值高的“甜气”。凝析油含量较低；为无色-乳黄色、透明，属于未成熟油。遂宁组水型多，有Na2HCO3、Na2SO和CaCl2型三种；矿化度变化大，由1．62-31．6g／L．总体上为弱矿化-接近淡水。而上覆层蓬莱镇组为35-50g/L，属强矿化水；下伏层沙溪庙组为60g/L，属于盐水。三者差别明显。凝析水在川西地区各气藏中广泛分布，在采气过程中，凝析水的含量及其化学成分通常基本保持不变。如果含量特别是化学成分发生了改变，则可能是生产井出水的前兆。

Suining gas pool is rich in natural gas with a little condensate and condensate water mixed with formation water,and it is a gas pool without edge water and bottom water.Gas content of hydrocarbon is over 98% in the natural gas composition produced from Suining gas pool.Due to the content of acid gas is very low in the reservoir,it can be transmitted directly by pipelines.The content of condensate is very low in Suining gas pool,so it belongs to immature oil.Suining formation has many characteristics such as many water types and large variable of salinity.