准噶尔盆地中部油气成藏期次及勘探方向

HYDROCARBON ACCUMULATION STAGES AND EXPLORATION DIRECTIONS IN THE CENTRAL JUNGGAR BASIN

综合利用圈闭形成时间法、生排烃史分析法、自生矿物同位素测年法、流体包裹体法和油藏地球化学法,分析准噶尔盆地中部已钻井揭示油藏的成藏期次与时间,认为中部1,3区块侏罗系油藏存在3期成藏:中晚侏罗世、早白垩世末和古近纪—现今;白垩系油藏存在2期成藏:早白垩世末和古近纪—现今;中部2,4区块侏罗系、白垩系仅存在1期成藏:早白垩世末—现今。指出各期次油藏的勘探方向:中部3区块北部是寻找早白垩世末形成的原生油藏的重点地区;中部1区块是寻找古近纪—现今形成的次生油藏的重点地区;中部2,4区块是寻找古近纪—现今形成的原生油藏的重点地区。

Hydrocarbon accumulation stages and times in the central Junggar Basin are analyzed by means of t rap formation time, hydrocarbon generation and expulsion history, authigenic mineral isotope dating, fluid inclusion and reservoir geochemistry. Jurassic reservoirs in block 1 and 3 have experienced 3 stages： Middle--Late Jurassic, the end of Early Cretaceous and Paleogene till now. Cretaceous reservoirs in block 1 and 3 have experienced 2 stages： the end of Early Cretaceous and Paleogene till now. Jurassic and Cretaceous reservoirs in block 2 and 4 have experienced 1 stage： the end of Early Cretaceous till now. Exploration directions in Each stage have been pointed out. In the north of block 3, primary reservoirs tormed in the end of Early Cretaceous should be focused on. In block 1, secondary reservoirs formed from Paleogene till now should be paid attention to. In block 2 and 4, primary reservoirs formed from Paleogene till now have great potential.