轮南地区奥陶系油气成藏特征

轮南地区奥陶系的油气资源非常丰富，但油气的分布十分复杂。通过对该区奥陶系石油地质特征、油气成藏特征及油气藏形成机理的研究，认为该区黑油主要来自中－上奥陶统油源岩，天然气则来自寒武系烃源岩的高温裂解。油藏的成藏期是在中新世吉迪克组沉积晚期－康村组沉积早期，气藏的成藏期是在上新世库车组沉积期。原油沿奥陶系顶面的不整合面向北运移，天然气则沿桑塔木和轮南断垒两组背冲式大逆断裂向上运移，在有利的圈闭中成藏。指出油气运移的几条有利路线，是今后油气勘探的方向

FORMATION CHARACTERISTICS OF ORDOVICIAN OIL AND GAS RESERVOIR IN LUNNAN AREA

The Ordovician in Lunnan area is very rich in oil and gas resources and complicated in oil/gas distribution. Based on the studies on geologic feature, oil/gas reservoir characteristics and forming mechanism of oil/gas reservoir in Ordovician, it is considered that the black oil is mainly derived from the source rock of Middle-Upper Ordovician, natural gas from Cambrian source rock with high temperature cracking. Oil reservoir formed in late period of Jidike formation-early period of Kangcun formation in Miocene, and gas reservoir formed in period of Kuqa formation Pliocene. Crude oil migrated northward along the unconformity in top surface of Ordovician and formed oil reservoir in favorable trap, natural gas migrated upward along two rows of reversed faults of Sangtamu and Lunnan fault horst. It is pointed out that several advantageous routes of hydrocarbon migration are the direction for oil and gas exploration in the future.