准噶尔盆地中央坳陷带包裹体特征及成藏期次分析

The Characteristics of Fluid Inclusions and Its Application to Identifying Oil Accumulating Stages in Central Depression,Junggar Basin

本文研究了准噶尔盆地中央坳陷带主力油层流体包裹体的特征,统计分析了各区块已揭示的主力油层的流体包裹体均一化温度,明确了主力油藏主成藏期流体包裹体均一化温度范围;在此基础上,通过单井埋藏史和热史的恢复,结合主力烃源生排烃热演化,确定了各区块主力油藏主成藏期发生的时间：中部1区块为新近纪渐新世（40 Ma）,中部2区块为晚白垩世早期（95-88 Ma）,中部3区块为白垩世末-古近纪早期（75-60 Ma）,中部4区块第一期成藏时间为早白垩世末（105-95Ma）,第二期成藏时间为晚白垩世晚期（85-72 Ma）。

Based on analysis of many fluid inclusion samples, the characteristics of fluid inclusions of the main oil reservoir was described in details in the central depression, Junggar basin. On basis of the above, the distribution of the homogenization temperature of fluid inclusions of the main oil reservoirs in the drilled wells of different block was statistically analyzed, the distributed scopes of homogenization temperature of fluid inclusions formed in the main accumulating stage of the main oil reservoirs was confirmed. By reconstructing burial history and heat history of the related single well, combined with the studied results of homogenization temperature distribution and the heat evolution history of the main hydrocarbon rocks in the main hydrocarbon generation depression, the main oil pools forming time in the different block was confirmed definitedly, that is, the main oil pools in the first central block formed since the Oligocene of Paleogene（since 40 Ma）, the main oil pools in the second central block formed during early stage of late Cretaceous（from 95 Ma to 88 Ma）, the main oil pools in the third central block formed from the end of the early Cretaceous to the early stage of Paleogene （from 75 Ma to 60 Ma）. the formation of main oil pools in the fourth central block endured oil filling twice, the first filling stage happened during the end of the early Cretaceous（from 105 Ma to 95 Ma）, the second filling stage happened during the late stage of the late Creta ceous（from 85 Ma to 72 Ma）.