鄂尔多斯盆地奥陶系岩溶古地貌气藏特征及勘探进展

依据古岩溶和碳酸盐岩成藏地质理论,系统分析了鄂尔多斯盆地奥陶系海相碳酸盐岩天然气成藏地质背景及非常规隐蔽性大型岩溶古地貌气藏的烃源、储层、盖层、圈闭及运聚规律等基本特征,提出了稳定地台区海相碳酸盐岩储层与圈闭是成藏要素中的关键因素。并以此为重点,深入研究了古岩溶成因和岩溶古地貌的发育特征,揭示了古风化壳孔、洞、缝网络与气藏圈闭形成的机制和分布规律。并通过古地貌模式的建立及其在实践中的应用,使奥陶系古风化壳天然气勘探不断取得了进展。

Characteristics of Gas Reservoir and Exploration Achievement for Ordovician Paleokarst Landform in Ordos Basin

According to the geologic theory of paleokarst and Carbonate reservoir-forming,the geologic background of natural gasreservoirs formation and accumulation in marine carbonate rock and the basic features of unconventional large subtle paleokarst gasreservoir in Ordos Basin, which include source rock, reservoir, cap rock, trap, migration and accumulation law, are analyzed systematically.And it is put forward that marine carbonate rock reservoir and trap in stable platform are the key factors. Starting From this point, it isstudied the cause of paleokarst formation and developed features of paleokarst landform, and revealed the mechanism and distributinglaw of the network formed by pores, caves and fissure in weathering crust. Through setting up the model of paleokarst landform andapplying it in practice, the achievement of natural gas exploration for paleo-weathering crust has been continuously made.