鄂尔多斯盆地大牛地气田地层水特征及成因分析

摘要

Based on the analysis of the enrichment and deficit of ion in the formation water,combined with the previous research,the gensis of formation water in Taiyuan,Shanxi and Lower Shihezi Formation in Daniudi Gas Field is analyzed.The result shows that the formation water in the study area is controlled by sedimentary environment,water-rock interaction,fluid mixing and evaporation effect.The formation water in each formation has high content of Br-,Ca2＋ and Sr2＋,and little content of Mg2＋ and Na＋.The enrichment of Br-in Lower Shihezi Formation and the chemical similarity of the formation water in different formations indicate the existence of water mixing.Much acid water from coal measures has an important effect on reservoir diagenesis.%通过研究地层水中离子的富集或亏损程度,并结合前人研究成果,对大牛地气田上古生界太原组、山西组和下石盒子组地层水成因进行了初步探讨。研究结果表明：研究区地层水受沉积环境、水-岩相互作用、流体混合作用及蒸发浓缩作用共同控制,各层系地层水均具有富Br-,Ca2＋,Sr2＋,贫Mg2＋,略微贫Na＋的特点;下石盒子组Br-的富集及各层系地层水化学特征的相似性共同表明了地层水混合作用的存在;煤系酸性地层水对储层砂岩的成岩作用有重要影响。