陕西铜川—延安地区油页岩及油气资源特征

鄂尔多斯盆地东南部的铜川—延安地区是我国油页岩资源最丰富的地区之一,其中,三叠系延长组是盆地内最具潜力的油页岩产出层位。为了掌握和评价该区三叠系延长组长7油页岩矿床特征、资源品级和勘探远景,为该区油页岩勘探开发提供依据,在对油页岩地质调查、钻探及测井等资料解释和样品分析的基础上,进行了综合研究和远景资源量估算。结果表明:该区油页岩厚度较大、油页岩段集中,分布稳定,含油率较高,为厚层中品级富—高硫油页岩;沉积环境控制了油页岩的厚度及含油率,半深湖—深湖与浅湖过渡带及湖湾环境是油页岩形成的最有利相带;该区仅500 m以浅的长7油页岩资源量达1 346.46×108t,干馏油页岩油资源量为63.70×108t,资源潜力巨大,具有大型—特大型油页岩矿床远景。

Characteristics of oil shale and oil gas resources in the Tongchuan-Yan’an area,Shaanxi Province

The Tongchuan-Yan’an area, the southeastern of Ordos Basin, is one of the richest oil shale resources areas in China. Triassic Yanchang Formation is considered as the greatest potential resource layer for oil shale exploration. In order to understand the deposit characteristics, grade quality and exploration prospect and to provide a reference for further exploration of oil shale in Chang 7 Member of Yanchang Formation in the study area, according to comprehensive data interpretation of geological survey, geological drilling, well logging and sample analysis, the prospective resource estimation reveals that the oil shale is large in thickness and high in oil content, and it has a concentrated and stable distribution, which is considered as medium-grade and sulfur-rich oil shale. Sedimentary environment has an important effect on the thickness and oil content of oil shale. The transition belt between semi-deep lake and shallow lake, and the lake-bay environment are the most favorable facies for the formation of oil shale. It is proposed that the amount of oil shale resource of Chang 7 with the depth below 500 meters has reached 1 346.46×10⁸ t, while the counterpart of carbonized oil shale has reached 63.70×10⁸ t. The resource potential of the study area is enormous, and implies the prospect of large and super-large oil shale deposits.