青海省南祁连盆地木里地区二叠纪烃源岩特征及评价

发布时间：2018-07-26 11:16

【摘要】：青海省木里地区经过钻孔取样发现地层中含有可燃冰,这对南祁连盆地冻土区可燃冰找矿工作具有十分重要的意义。因此对该区可能作为生油气层的地层进行研究是具有很大意义的。通常我们又将可作为生油气层的地层叫做烃源岩,并且按一定方法对其进行评价。本文主要是通过对工作区内二叠系地质剖面的测制、野外区域地质调查、野外样品采集、实验室样品数据测试、室内剖面图和柱状图绘制、样品数据分析来对二叠系烃源岩的生储盖组合分析。对研究区目标层位展开一系列工作,发现研究区二叠纪地层主要以灰色微晶灰岩、亮晶灰岩、长石石英砂岩、岩屑石英砂岩、石英砂岩为主,可见少量紫红色泥岩。在薄片观察基础下发现,研究区砂岩一般成熟度不高、分选也十分不好,偶尔发育有裂隙和空洞,但多被后期充填。对二叠纪可作为烃源岩的灰岩、泥岩进行热解分析,发现二叠纪烃源岩能作为生油气的有机碳含量很低,二叠纪中能作为生油气层的灰岩、泥岩样品数据显示二叠纪烃源岩有机碳含量基本为0,可初步判定二叠纪烃源岩为无效烃源岩。然后结合对二叠纪烃源岩的热演化程度和沉积相分析,综合结果,得出二叠纪中能作为生油气层的灰岩、泥,页岩在沉积时其中有机碳含量就十分低下。虽然,本文对二叠纪烃源岩的总体特征评价为无价值烃源岩,但这也具有十分重要意义,能为后来工作者提供一定的科学依据,避免造成无效损失。
[Abstract]:It is found that there is combustible ice in the stratum through borehole sampling in Muli area of Qinghai Province which is of great significance to the prospecting of combustible ice in the frozen soil region of South Qilian Basin. Therefore, it is of great significance to study the strata which may be regarded as oil and gas generating zones in this area. Usually, the formation that can be used as source rock is called source rock and evaluated according to certain method. This paper is mainly through the measurement of the Permian geological profile in the working area, the field regional geological survey, the field sample collection, the laboratory sample data testing, the drawing of the indoor profile and the histogram. Sample data analysis is used to analyze the generation, reservoir and cap assemblage of Permian source rocks. It is found that the Permian strata in the study area are mainly composed of grey microcrystalline limestone, bright grained limestone, feldspar quartz sandstone, lithic quartz sandstone, quartz sandstone and a small amount of fuchsia mudstone. On the basis of thin slice observation, it is found that the sandstone in the study area is generally not high in maturity and poor in sorting. Occasionally there are cracks and voids, but most of them are filled in later stage. The pyrolysis analysis of Permian limestone and mudstone as source rock shows that Permian source rock can be used as hydrocarbon source rock with very low organic carbon content, and Permian source rock can be used as oil and gas generating layer limestone in Permian. The data of mudstone samples show that the organic carbon content of Permian source rocks is basically 0, which can be preliminarily determined as ineffective source rocks. Based on the analysis of the thermal evolution and sedimentary facies of Permian source rocks, it is concluded that the organic carbon content in the limestone, mud and shale is very low in the Permian period. Although the general characteristics of Permian source rocks are evaluated as worthless source rocks in this paper, this is also of great significance, which can provide some scientific basis for future workers and avoid invalid losses.
【学位授予单位】：中国地质大学(北京)
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：P618.13

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