为了研究普光气藏储层流体的演化过程,对气藏包裹体进行了显微观察和显微测温研究。结果表明:普光气藏储层流体包裹体可划分为3期,即成岩早期(第1期),成岩晚期早阶段(第Ⅱ期)和成岩晚期晚阶段(第Ⅲ期)。第1期以气液水包裹体和液相水包裹体为主,均一温度为85~117℃,盐度(叫B)为15.55%~20.43%,属于浅埋藏环境;第Ⅱ期包裹体类型有含沥青气相烃包裹体、残余沥青包裹体和气液水包裹体,含沥青气相烃包裹体及残余沥青包裹体是由液相烃包裹体、气一液烃包裹体热裂解而成的,该期包裹体均一温度为116~168℃,盐度为4.94%~19.95%,为中一深埋藏环境;第Ⅲ期包裹体主要为气相烃、烃一水包裹体和气液水包裹体,均一温度为133~250℃,盐度为4.48%~21.05%,属深埋藏环境。从第Ⅰ期到第Ⅲ期随着埋深的增加,均一温度依次升高,盐度大致呈降低的趋势。
This paper studies the evolution process of Puguang gas reservoir based on the microscopic ob- servations and the micro thermometry measurement of its inclusions. The result shows that the inclusions are formed in three phases, respectively: the early period of diagenesis(inclusions of period Ⅰ ), the early stage in the late period of diagenesis (inclusions of period Ⅱ ),and the late stage in the late period of dia- genesis(inclusions of period Ⅲ). In period Ⅰ , they are mainly the gas-liquid H2O inclusions, with the homogenization temperature ranging from 85℃ to 117℃, and the salinity 15.55%-20.43%, belonging to shallow buried environment. In period Ⅱ , there are gas-liquid H2O inclusions,gas hydrocarbon inclusions containing bitumen and residual bitumen inclusions. The latter two are thermal cracked from Liquid phase hydrocarbon inclusions, gas-liquid hydrocarbon inclusions. The homogenization temperature gas-liquid H2O inclusions range from 116℃ to 168℃, and the salinity is 4.94%-19.95%, belonging to middle-deep buried environment. In period Ⅲ, inclusions are mainly hydrocarbon inclusions, hydrocarbon-H2O inclu- sions and gas-liquid H2O inclusions, with the homogenization temperature ranging from 133℃ to 250℃, and a wide range of salinity:4.48%-21.05%, corresponding to the dry gas stage,belonging to deep burial environment. From stage Ⅰ to stage Ⅲ, with the increase of depth and evolution, the homogenization temperature increased gradually and the salinity showed a decreasing trend.