运用流体包裹体确定鄂尔多斯盆地上古生界油气成藏期次和时期

Using Fluid Inclusion of Reservoir to Determine Hydrocarbon Charging Orders and Times in the Upper Paleozoic of Ordos Basin

对鄂尔多斯盆地上古生界68口井110块流体包裹体样品的荧光观察,60口井75块样品的显微测温、测盐等系统分析结果表明,该区上古生界砂岩储层发生过6期热流体活动,均与油气成藏有关,并以第2—6期的天然气成藏为主。结合埋藏史分析可知,油气成藏分别发生在距今220-190 Ma(T3中期-J1中期)、190-150 Ma(J1中期-J2中期)、150-130 Ma(J2中期-J2 末期)、130-113 Ma(J2末期-K1中早期)、113-98 Ma(K1中早期-K1中晚期)、98-72 Ma(K1中晚期-K1末期),并认为早侏罗世中期-中侏罗世末期、中侏罗世末期-早白垩世末期是鄂尔多斯盆地上古生界天然气的主要成藏时期。

In this research,110 fluid inclusion samples from 68 wells in the Upper Paleozoic of Ordos Basin have been obtained and are used to measure the fluorescence colors for hydrocarbon inclusions. Among them, 75 fluid inclusion samples from 60 wells are used to measure the homogenization temperature mainly in trails, salinity for aqueous inclusions and the hydrocarbon inclusions. The result indicates that there are six times of thermal fluid flow in the sandstone reservoirs of the Upper Paleozoic,all of which are relative to hydrocarbon charging, statistically dominated by gas charging. By integrating the average homogenization temperatures with burial historical curves,the six charging orders correspond to the 220--190 Ma（the Middle Late Triassic-the Middle Early Jurassic period）, 190--150 Ma（the Middle Early Jurassic-the Middle Middle Jurassic period）, 150--130 Ma（the Middle Middle Jurassic-the Late Middle Jurassic period）, 130-- 113 Ma（the Late Middle Jurassic-the early of the Middle Early Cretaceous period）, 113--98 Ma（the early of the Middle Early Cretaceous-the late of the Middle Early Cretaceous period） and 98--72 Ma（the late of the Middle Early Cretaceous-the Late Early Cretaceous period） ,respectively;It is suggested that the critical moment is at the Middle Early Jurassic-the Late Middle Jurassic period and the Late Middle Jurassic period-the Late Early Cretaceous period.