胶莱盆地烃源岩分布及有机地球化学特征

DISTRIBUTION AND ORGANIC GEOCHEMICAL CHARACTERISTICS OF HYDROCARBON SOURCE ROCKS IN THE JIAOLAI BASIN

胶莱盆地为一中生代陆相残留盆地,其暗色泥页岩主要发育于莱阳组水南段。运用野外露头、地震、钻井等资料,综合沉积相、古水流方向的研究,对水南段暗色泥页岩的展布特征进行了分析;在此基础上,应用多项分析测试技术,分别对胶莱盆地莱阳凹陷、平度—夏格庄凹陷、高密—诸城凹陷3个构造单元水南段暗色泥页岩的有机质丰度、类型和热演化程度特征进行了详细分析。研究结果表明,莱阳凹陷和平度—夏格庄凹陷是胶莱盆地源岩发育最好的区域,有机质丰度可达好、较好烃源岩标准,类型以Ⅰ型、Ⅱ1型为主,且处于热演化成熟阶段,因此是胶莱盆地油气勘探的有利区域。

Based on the data of field outcrops and wells in the Jiaolai Basin, the authors believed that the dark mudshales mainly developed in Shuinan Member of Laiyang Formation. Distribution characteristics of the dark mudshales in Jiaolai Basin were analyzed on the basis of measuration and exploration of field sections, combining with the seismic data and the study on sedimentary facies and paleocurrent orientations. Moreover, the abundance, types and maturity of the organic matters from the dark mudshales in Shuinan Member of Laiyang Formation, which are in different tectonic units of Jiaolai Basin, such as Laiyang Sag, Pingdu-Xiagezhuang Sag, Gaomi-Zhucheng Sag, were studied by means of several analysis methods. Study results show that hydrocarbon source rocks in Jiaolai Basin mainly developed in Laiyang Sag and Pingdu-Xiagezhuang Sag. The abundance of organic matter is higher and can come up to the standard of fairly good hydrocarbon source rocks or good hydrocarbon source rocks. Most of the organic matters are type Ⅰ to Ⅱ1. The organic matter is in the evolution stage of maturation. So, the Laiyang Sag and Pingdu-Xiagezhuang Sag are the favorable exploration areas in the Jiaolai Basin.