论文部分内容阅读
石炭系是柴达木盆地油气勘探的新层系,油气勘探程度低,但发育厚度大的高有机质丰度泥页岩,具有很好的页岩气资源潜力。通过对德令哈坳陷石炭系露头剖面进行实测和钻井岩心分析,明确石炭系泥页岩空间展布特征。测定样品有机地球化学参数、孔渗特征,并且进行等温吸附和渗流实验,分析其储集特征。结合德参1井盆地模拟分析,研究石炭系页岩气成藏事件,划分德令哈坳陷石炭系页岩气系统。研究表明:石炭系泥页岩广泛发育,埋深较大但未发生变质;泥页岩有机质丰度较高,有机质类型主要为Ⅱ2型和Ⅲ型,处于成熟—高成熟演化阶段;上石炭统泥页岩发育优于下石炭统;泥页岩表现为低孔低渗特征,孔隙度在1.89%~5.48%,渗透率为(0.115~2.7)×10-7μm2;上覆地层发育厚层泥页岩可以提供良好的盖层条件;古近纪末—现今为页岩气系统形成的关键时期;上石炭统克鲁克组钻遇天然气显示,证实了德令哈坳陷石炭系页岩气系统的存在。在泥页岩厚度、埋深、TOC含量、成熟度等条件综合评价基础上,将德令哈坳陷划分为德令哈页岩气系统与埃北页岩气系统。
Carboniferous is a new oil and gas exploration layer in the Qaidam Basin. It is characterized by low shale oil and gas exploration but richly developed shale of high organic matter abundance and high shale gas potential. Through the measurement and drilling core analysis of Carboniferous outcrop section in Delingha depression, the spatial distribution characteristics of shale in Carboniferous are clarified. The samples were measured for organic geochemical parameters and porosity and permeability, and isothermal adsorption and seepage experiments were conducted to analyze their reservoir characteristics. Combining with the simulation analysis of Well D 1 in Shahejie Formation, this paper studies the hydrocarbon accumulation events of shale gas in Carboniferous series, and divides the Carboniferous shale gas system in Delingha depression. The results show that the Carboniferous shale has a wide range of development with large buried depth but no metamorphism. The shale has a high abundance of organic matter, and the organic matter types are mainly Type II2 and Type III, which are in the stage of mature-high maturity. The Upper Carboniferous Shale development is superior to Lower Carboniferous. Shale is characterized by low porosity and low permeability with porosity of 1.89% -5.48% and permeability of (0.115 ~ 2.7) × 10-7μm2. Thick mud Shale can provide good cover conditions; the end of the Paleogene - now the key period of Shale gas system formation; the Upper Carboniferous Cretaceous group showed natural gas, confirming the Carboniferous shale gas in the Delingha depression The existence of the system. Based on the comprehensive evaluation of shale thickness, burial depth, TOC content and maturity, the Delingha depression is divided into Delingha shale gas system and Ersi shale gas system.