摘要
本文通过对赤水凹陷T、P和S气层中天然气碳和氩同位素特征的分析,指出碳同位素组成的倒转现象和δ^(13)C_1>δ^(13)C_2的反常特征。认为倒转现象主要与过成熟的演化有关,同时也受母质类型和运移的影响。反常特征是与天然气的混合及所经历的较高古地温有关。在同位素特征分析的基础上,对天然气的成因类型和气源进行了探讨,认为S主要为油型裂解气,可能还有C—O的气体混入。T—P系主要为煤成气和自生自储油型裂解气的混合气。
On the basis of the analysis of isotopic characteristics of carbon and argon of the natural gas in the Triassic, Permian and Silurian formations in the Chishui depression, Guizhou province. It is show that, an overturning of the carbon isotopic compositions and an anomalous phenomenon with δ^(13)C_1>δ^(13)C_2 is observed. This study suggests that the overturning phenomenon is related to over-mature evolution of the natural gas, meanwhile it may be affected by various type of organic matters and its migration. The anomalous phenomenon of δ^(13)C_1>δ^(13)C_2 is related to the mixing of natural gas from various sources and high paletemperature during their evolution. Based on an analysis of isotopic characteristics, for the discussion of gas source, its type and formation the gas from Silurian formation is considered as petroliferous gas and may be mixed with gas migrated from Cambrian-Ordovician formations. The gas in Triassic and Permian are considered as a mixture of coaliferous gas and petroliferous gas from surrounding source rock formations.
出处
《石油勘探与开发》
SCIE
EI
CAS
CSCD
北大核心
1990年第1期32-38,13,共8页
Petroleum Exploration and Development
