普光地区上三叠统须家河组烃源岩地球化学特征

Geochemistry Characteristics of Source Rocks in Triassic Xujiahe River Group of Puguang Area

普光地区的烃源岩主要发育在上三叠统须家河组,研究上三叠统须家河组的烃源岩状况,将为本研究区上三叠统须家河组进行的油气勘探提供重要的依据,对以后区域的油气评价和勘探目标的选择具有十分重要的意义。本文将以测井、岩性、地球化学等勘探资料为基础,掌握研究区上三叠统须家河组烃源岩的地球化学特征。通过对普光地区30余口井及其相关资料的整理后,运用统计和相关计算公式,取得了以下认识：须家河组烃源岩主要分布在须三、须五段。有机质丰度分布均衡,平均值为6.57%,为生烃能力较好的烃源岩。烃源岩的生烃潜量主要分布在0.2-20 mg/g。烃源岩有机碳含量与其生烃潜量呈显著的正相关关系。烃源岩有机质的类型大部分为Ⅱ2型和Ⅲ型,少量为Ⅱ1型,生油潜力小,但可生成天然气。烃源岩的平均镜质体反射率为1.78%,评价为成熟的烃源岩。平均热解峰顶温度（Tmax）为486℃,达到高成熟-过成熟阶段,主要生成湿气-干气。

Puguang area locates in the northeastern of Sichuan basin, the continental formation hydrocarbon source rocks mainly developed in Triassic Xujiahe river group. To fully understand hydrocarbon source rocks of Triassic Xujiahe river group will provide important basis for the oil and gas exploration in this area. It is of great significance for future zone evaluation and target selection. In this article, based on logging, lithology, and geochemical exploration data, geochemical characteristics of source rocks and potential resources in the study area were analyzed. The results show that： hydrocarbon source rocks of Xujiahe river group are mainly distributed in Xu 3 member and Xu 5 member, the organic abundance distribution is balanced, with mean value of 6.57%. Hydrocarbon potential of hydrocarbon source rocks is 0.2- 20 mg/g, organic carbon content of hydrocarbon source rocks has positive relationship with the hydrocarbon potential. Organic matter types of hydrocarbon source rocks are mainlyⅡ2 andⅢ, slightly Ⅱ1. Mean vitrinite reflectance of hydrocarbon source rocks is 1.78%,so they are mature source rock.