火成岩油气藏的烃源、成藏机理及勘探潜力

The Hydrocarbon Source,Accumulation Mechanism and Exploratory Potential of Igneous Reservoir

全面回顾了国内外火成岩油气藏的研究进展。指出,尽管目前已发现的具有商业价值的火成岩油气藏以有机成因为主,但对无机成因油气藏要给予高度重视。详细论述了火成岩油气藏的烃源及无机成因烃的形成机理,阐明地幔射气、晚岩浆期温度500℃以下封闭体系内C-O-H流体重新平衡和岩浆期后阶段矿物与流体的费托合成是无机成因烃的主要来源。我国东部盆地断陷期烃源岩发育良好,区域火山岩地幔包体和火山区温泉气内均含有地幔来源的烃类,碱性和过碱性花岗岩及基性和超基性岩组合具备费托合成烃的条件;表明火成岩油气藏具有巨大的勘探潜力。

The study progresses of igneous petroleum reservoirs at home and abroad are reviewed. The results show that the commercial igneous reservoirs are dominated by those with biogenic hydrocarbons, but inorganic petroleum reservoirs should be paid great attention to. The hydrocarbon source and the mechanism of inorganic hydrocarbon generation of igneous reservoirs are discussed. It is illustrated that primary mantle outgassing, the rebalancing of C-O-H fluid within the closed system in late-magmatic stage of less than 500℃ and the mineral-fluid Fischer-Tropsch （FT） reactions in post-magmatic stage are the main sources of inorganic hydrocarbons. The source rocks in faulted period of basins in eastern China are well developed, with mantle-derived hydrocarbons in regional volcanic mantle inclusions and volcanic spring gas. The combinations of Alkaline-peralkaline granites and basic/ultrabasic igneous rocks are. of suitable for FT reactions. These indicate that igneous reservoirs have huge potentials for petroleum exploration.