苏里格气田凝析油反凝析污染对地层伤害程度研究

鄂尔多斯盆地苏里格气田部分井试采产少量凝析油。利用该气田的脱气油样、气样和水样．在气油和气水共渗情况下测定3口井9块(次)岩心的相对渗透率．测试结果表明：在含水饱和度从0增至最小原生水饱和度时渗透率下降较慢；从最小原生水饱和度增至最大原生水饱和度时渗透率下降较快，对地层渗透率的伤害比较严重。但增加的液相中相当一部分是凝析油析出与吸附作用所致，实际渗透率伤害程度比实验分析结果要低，男据5口井样品的相态实验结果，实际生产中地层压力下降后，最大凝析液体积远小于烃类流体总体积，因此在苏里格气田开发中后期，凝析油反凝析污染或凝析油吸附对地层渗透率的伤害不严重。图1表3参5

The damage of reverse-condensate pollution of condensate on the formations of the Sulige Gas Field, Ordos Basin

Only a little condensate had been found when some gas well are producing test in Sulige Gas Field, Ordos Basin. The analyses of relative permeability of 3 wells and 9 set cores under the condition of gas-oil and gas-water coexisting by using gas-free oil sample, gas sample, water sample show that permeability dropped slowly when water saturation increased from 0 to minimum original-water saturation and dropped sharply when minimum original-water saturation increased to maximum original-water saturation. The damage for real formation permeability is lower than that of experiment. According to the result from five well's phase experiment, the maximum volume of condensate is less than the whole volume of hydrocarbon when formation pressure drops down. Therefore, the damage of permeability that comes from condensate at medium-last development stage of Sulige Gas Field would be slight.