准噶尔盆地乌夏地区地层水与油气保存条件

Preservation conditions for formation water and hydrocarbon in Wuxia area,Junggar Basin

针对准噶尔盆地乌夏地区地质流体分布的复杂特征,从水文地质条件和地层水化学特征分析入手,剖析了地层水与油气保存条件的关系。研究认为,处于交替阻滞带和交替停止带的二叠系、三叠系的大气水下渗阶段时间较短暂,而压榨水阶段时间较长,且受深部热液影响大,地层水以CaCl2和NaHCO3水型为主,矿化度高,钠氯系数和脱硫酸系数低,属于未破坏或微破坏型,保存条件优越,有利于油气聚集成藏。

Based on the complicated distribution of geological fluid in Wuxia area of the Junggar Basin,from the aspects of hydrogeological conditions and formation water chemical characteristics,it has been discussed in this paper the relationship between formation water and hydrocarbon preservation.Studies have suggested that,Permian and Triassic experienced short stages of atmospheric water seepage and long stages of water compression since they were in alternative blocking and stopping belts.Severely influenced by deep thermal fluids,the formation water was mainly CaCl2 and NaHCO3 types with high salinity as well as low sodium chloride and de-sulfate coefficients.It was not or seldom damaged and provided excellent conditions for the preservation of hydrocarbon.