桂中坳陷中泥盆统烃源岩特征

桂中坳陷泥盆系发现多处油气苗及沥青，具有良好的石油地质条件。对桂中坳陷中泥盆统烃源岩进行了研究，认为烃源岩的分布受沉积相控制明显，主要为台盆相暗色泥页岩和深灰色、灰黑色泥灰岩；烃源岩有机质丰度高，有机质类型为混合型和腐殖型，总体为混合型，生烃源来自于海洋性浮游生物和陆生植物，具有混合型母质来源的特征；烃源岩R_o值都大于1.5%，有的甚至达到2.03%，均属于高成熟阶段，现今以提供干气为主；石炭纪早期开始生烃，石炭纪中晚期-二叠纪末期处于生油高峰期，至三叠纪早期生排烃结束。

Characteristics of Middle Devonian hydrocarbon source rocks in the Guizhong (Middle Guangxi) depression

Many seepages and petrolenes have been found in middle Devonian formation in Guizhong (Middle Guangxi) depression, and the geological condition is good for hydrocarbon reservoirs. This paper studies the hydrocarbon resource rocks and approves that the distribution of the hydrocarbon resource rocks is controlled obviously by sedimentary facies, and the hydrocarbon resource rocks are mainly the dark mud shale and deep grey and grey black muddy limestone; the hydrocarbon resource rocks organic material abundance is high, the organic material forms are type II and III, but the type II as the whole. Hydrocarbon generation sources are the oceanity floating organisms and land plants, have the resource feature of mixed mode parent material, and their Ro values are more than 1.5% (some up to 2.03%). The hydrocarbon resource rocks are in their mature period, and mainly supply dry natural gas. In the early stage of Carboniferous Period they began to generate hydrocarbon, during the middle and late stage of Carboniferous and the last stage of Permian they were in oil forming generation peak period, and in early stage Triassic, the hydrocarbon generation and expulsion finished.