西峰油田延长组长8段储层流体作用期次分析

采用显微荧光技术以及包裹体显微测温技术,结合鄂尔多斯盆地西峰油田埋藏史及地热史演化过程模拟,确定了该区油气运移主要分两期,第一期发生于中、晚侏罗世,第二期发生于早白垩世末期,该期是鄂尔多斯盆地西峰地区中生代油气运聚的重要时刻。油气运聚的第一期和第二期分别对应于早成岩B期和晚成岩A期成岩阶段。由于该区盐水包裹体以石英裂缝中形成的为主,包裹体的保存条件相对较差,使得均一温度具有一定的多解性,因此制定了裂缝中流体包裹体测温数据应用的筛选原则,为类似情况流体包裹体的应用提供了参考。

Analysis of hydrocarbon migration stages in the 8th member of Yanchang Fm in Xifeng oilfield

In combination with the evolutionary process simulation of burial history and geothermal history of Xifeng oilfield in Ordos basin, microfluorometric technology and microscopic thermometry technology of inclusion have been applied in the study, which indicates that hydrocarbon migration in the study area has mainly occurred in two stages. The first migration stage occurred in the Middle and Late Jurassic, while the second migration stage occurred at the end of Early Cretaceous, which was a critical period of Mesozoic hydrocarbon migration and accmulation in Xifeng area, Ordos basin. The first and second stages of hydrocarbon migration correspond to the early diagenetic stage B and the late diagenetic stage A, respectively. Since the brine inclusions in the area have mainly been formed in quartz fractures, the preservation conditions of inclusions are relatively poor, leading to a certain interpretation ambiguity of the homogenization temperatures. The screening principle of applying thermometric data of fluid inclusions met in the fractures has, therefore, been made, which can be used as reference for the application of similar inclusions.