湘鄂西地区五峰–龙马溪组富有机质页岩段沉积–地化特征<br>Sedimentation and Geochemistery Features of the Organic-Riched Shale in Wufeng-Longmaxi Formation, West of HuNan-HuBei Province

Abstract

湘鄂西地区五峰–龙马溪组为一套厚层的泥页岩层，根据其沉积特征确定该区沉积相类型为碎屑岩陆棚相，进一步细分为浅水陆棚和深水陆棚亚相。结合沉积和地球化学特征分析，表明：五峰组–龙马溪组下段以灰黑色、深灰色硅质页岩、炭质页岩和笔石页岩为主，具有连续性沉积，平均厚度达50 m左右，区域分布稳定，埋藏深度较浅，TOC平均值达1.33%，热演化程度较高，有机质类型以大多以Ⅱ型为主，是页岩气发育的有利层段。经河页1井钻井证实，该区五峰–龙马溪组具有一定的含气性。因而开展页岩气沉积、地化特征等基础研究，对于该区页岩气勘探工作具有重要地质意义。 Hunan-Hubei region Wufeng-Longmaxi Formation is a thick layer of mud shale, according to its sedimentary characteristics determine the sedimentary types of clastic shelf, shallow surface canopy and deep surface shed further subdivided into Asia. Combined deposition and Earth chemical features analysis, indicates that: Wufeng-Longmaxi Formation Xia paragraph to ash black, and deep grey silicon mass page rock, and carbon mass page rock and pen stone page rock mainly, has continuity deposition, average thickness up50 maround, regional distribution stability, buried depth more shallow, TOC average up 1.33%, hot evolution degree higher, organic matter type to most to Ⅱ type mainly, is page rock gas development of enabling layer paragraph. River page 1 drilling confirms that the Wufeng-Longmaxi Formation has a certain set of gas-bearing. Geochemical characteristics of shale gas deposits, such as basic research, for shale gas exploration work in the area are of great geological significance.