The Geochemical Characteristics of High Quality Hydrocarbon Source Rocks- A case study of Hailaer Basin

摘要

The distribution of high quality hydrocarbon source rocks plays an important role in the accumulation of oil and gas. As a result, the identification of geochemical characteristics of high quality source rocks is the key to discriminate the distribution of high quality source rocks accurately. By core observation and sample analysis, taking Wuerxun-Beier depression in Hailaer Basin as the target regions, we make accurate discrimination of high quality hydrocarbon source rock developmental characteristics and comparison with common source rocks. The research shows that: (1) the hydrocarbon expulsion efficiency in study zone is high due to the alternating deposits of high quality hydrocarbon source rocks and sandstones. The high quality hydrocarbon source rocks deposited in the reducing environment to strong reducing ones, whereas common rocks deposited in oxidizing environment to weak oxidizing ones. (2) the occurrence of organic matter of high quality hydrocarbon source rocks is mainly in stratified enrichment type. The organic matter develops parallel bedding or basic parallel bedding. However, the distribution of organic matter of common source rocks is porphyritic and heterogeneous, or interrupted lamellar. (3) the hydrocarbon potential of high quality hydrocarbon source rocks is more than ten times that of common source rocks. (4) the content of organic carbon in high quality source rocks is high and the content of chloroform asphalt "A" is relatively low, which reflects that the hydrocarbon expulsion efficiency of high quality source rocks in the sand-shale interbeds of study zone is high.