渤南洼陷孤西深洼带的煤成气

Coalformed gas in Guxi deep land of Bonan subsag.

渤南深洼区目前还没有钻遇偏腐殖型或腐殖型烃源岩 ,但是孤西深洼带天然气甲烷及其同系物碳同位素特征反映主要为煤成气。其甲烷碳同位素值均大于 - 40‰ ,乙烷碳同位素值大于 - 2 8‰。甲、乙烷碳同位素值明显偏重 ,尤其是乙烷碳同位素值反映其为煤成气的特征。从天然气同位素特征分析 ,孤西深洼带存在煤成气。

No partial humic or humic source rocks are discovered in the Bonan deep subsag during drilling phase, but the characteristic of carbon isotopes of methane and its homologs in Guxi deep subsag belt reflects that the natural gas is coalformed gas dominantly. Its methane carbon isotope is heavier than -40‰ , ethane carbon isotope is heavier than -28‰ . Methane and ethane carbon isotopes are clearly heavier, especially ethane carbon isotope shows that it is characteristic of the coalformed gas. Coalformed gas exists in Guxi deep subsag belt from the point of the analyzing the isotope characteristics of the natural gas.