二连盆地赛51上古生界碳酸盐岩潜山油藏的发现与启示

Discovery and Implications of Sai-51 Carbonate Buried Hill Reservoir of Upper Palaeozoic in Erlian Basin

通过剖析二连盆地赛汉塔拉凹陷赛51潜山油藏的成藏条件,发现赛51潜山油藏的主控因素有三:一是有丰富的中生界油源供给;二是潜山背景下的大型背斜构造发育完整;三是古生界碳酸盐岩基岩经历长期风化剥蚀形成的风化壳储集条件良好。区域调查发现,二连盆地有十多个中生界富油凹陷,其基岩多为古生界碳酸盐岩,同时又具有基底复背斜、复向斜相间排列的构造背景,与赛51潜山油藏背景类似,推测该盆地其他富油凹陷具有形成古生界潜山油藏的条件,可以形成区域规模分布。

By analyzing the hydrocarbon accumulation conditions of Sai-51 buried hill reservoir in Saihantala Sag of Erlian Basin,it was found out that there were three main factors controlling the Sai-51 reservoir:①there was abundant Mesozoic oil source supply;② there developed a large-scale of complete anticlines under the background of buried hill;③the basement composed of Palaeozoic carbonate rocks had undergone long term of weathering process,where the reservoir condition of the weathering crust was good.The regional investigation shows that there are more than 10 Mesozoic oil-enriched sags in Erlian Basin,and most of them have basement rocks composed of carbonate.Moreover,anticlinorium and synclinorium are arranged alternately in the basement rocks of Erlian Basin.Therefore,Palaeozoic buried hill reservoirs may be of the same size of distribution in Sai-51 Sag,it is the area for further exploration.