阿克库勒及其邻区地层水同位素特征和油气地质意义

THE ISOTOPES COMPOSITION FORMATION WATERS IN AKEKULE AND ADJACENT,TARIM BASIN

阿克库勒及其邻区主要油气储层的地层水以高矿化度为特征,长期以来多数人认为这类地层水是互不沟通的深层封存环境的产物。通过对该区地层水的系统采样分析,依据地层水的同位素组成特点及所反映的成因环境,提出:1阿克库勒及其邻区主要储层的地层水同位素具有相同的组成,反映了它们之间的成因联系;2氢(δD)和氧(δ18O)同位素明显偏轻,δD最大值为-42.0‰,最小值为-66.0‰,δ18O最大值为2.7‰,最小值为-6.0‰,表现为有地表水渗混溶滤成因的地层水;3通过对比研究区内地层水的主要成因是地表水渗流和溶解地层中的NaCl所形成高矿化度地层水。因此,对阿克库勒及其邻区油气的运聚、保存条件需进行进一步的研究。

The formation waters contain much higher concentrations of solids in Ordovician, Carboniferous and Triassic reservoirs at Akekule and adjacent, which were considered as forming in a closed hydrogeological environment and disconnected each other. The new concludes are made by the analysis of the isotopes of formation waters ：①the isotopes of the formation waters have the same composition; ②the δ^18O are lighter,δD is from -42.0‰ to -66.0‰ and δ^18O from 2.7‰ to -6.0‰， maybe composed with surface water and formation waters ;③the formation of the oilfield waters is the result of the surface water leached the NaCl containing in the sediments in the area. The influence of the opening environment in migration and accumulation of oil and gas must be taken into consideration in the exploration in Akekule and adjacent.