青海南部冻土区二叠系天然气水合物生储特征分析

发布时间：2018-05-08 18:15

本文选题：天然气水合物 + 乌丽-开心岭冻土区　；参考：《中国地质大学(北京)》2017年硕士论文

【摘要】：天然气水合物是一种新型的清洁能源,潜在储量巨大。天然气水合物的勘探、开发和利用具有重大的意义。青藏高原作为我国面积最大、连续性最好、冻土厚度最稳定的冻土区,是我国天然气水合物研究的重点区域。为了评价青藏高原冻土区天然气水合物的成矿潜力,2014年和2015年,中国地质调查局油气资源调查中心分别在开心岭和乌丽地区布置施工了 TK1井和TK2井。本论文中的各类数据资料均主要来源于这两口钻井。根据野外录井资料及岩心测试数据,对钻遇地层的沉积环境、烃源岩和储层特征进行了分析,得到了研究区二叠系地层天然气水合物生储、特征的初步结论:(1)根据野外录井资料,结合生物化石鉴定结果、地球化学测试和XRD测试结果,对TK1井和TK2井的沉积相有了较为全面的认识。TK1井钻遇的地层为海陆过渡相,位于活动大陆边缘;TK2井钻遇的地层为一套火山碎屑岩,位于岛弧环境。两者之间可能存在一个弧后前陆盆地。沼泽煤层、三角洲前缘的细粒沉积岩,以及海相泥岩等均可作为潜在烃源岩层段;三角洲相的河道砂体、滨浅海的砂体,以及火山碎屑岩等均有成为储集层的潜力。(2)整合烃源岩样品岩石热解、生物标志化合物和镜质体反射率测试分析结果,对研究区的烃源岩特征有了初步了解。两口井的烃源岩有机质类型以混合型为主,干酪根成熟度很高,有机碳含量(TOC)较高,而生烃潜量(S1+S2)很低。综合分析认为,现阶段地层中的烃源岩已不具备大量生排烃的能力,残留在地层中的碳多为死碳;但有机质丰度经过恢复后总体评价很好,意味着在烃源岩演化的某个阶段曾经大量生成并排出了油气,具有为天然气水合物提供气源的潜力。(3)根据TK2井钻井过程中出现的气体异常现象记录,结合中子孔隙度测井曲线和岩心观察,对两井有利储集层段进行筛选,并对样品进行薄片观察、孔渗实验和压汞实验。分析认为,两口井的储集空间以裂隙为主,孔隙次之。其中裂隙中的破碎带、未被完全充填的宏观裂隙和微裂隙对储层物性有极大的改善作用;原生孔隙对储层物性的贡献基本可以忽略;溶蚀孔隙对储层物性也有较大的改善作用。地层整体具有良好的储集能力。
[Abstract]:Natural gas hydrate is a new clean energy source with huge potential reserves. The exploration, development and utilization of natural gas hydrate are of great significance. The Qinghai-Xizang Plateau is the most stable permafrost region with the largest area, the best continuity and the most stable thickness in China, which is the key area for the study of natural gas hydrate in China. In order to evaluate the mineralization potential of natural gas hydrate in permafrost region of Qinghai-Xizang Plateau, TK1 well and TK2 well were constructed in 2014 and 2015 by China Geological Survey Oil and Gas Resources Survey Center in Xingling and Wuli areas, respectively. All kinds of data in this paper are mainly from these two drilling wells. Based on the field logging data and core test data, the sedimentary environment, source rock and reservoir characteristics of the drilled strata are analyzed, and the gas hydrate generation reservoirs in the Permian strata in the study area are obtained. (1) based on field logging data, combined with biofossils identification results, geochemical tests and XRD test results, the sedimentary facies of well TK1 and well TK2 have been fully recognized that the strata drilled in well TK1 are transitional facies of sea and land. The strata in TK2 well located on the active continental margin are a set of pyroclastic rocks and are located in the island arc environment. There may be a back-arc Foreland basin between the two. Marsh coal seam, delta front fine grain sedimentary rock and marine mudstone can be used as potential source rocks, delta facies channel sand body, shoreline shallow sea sand body, etc. The pyrolysis, biomarker compounds and vitrinite reflectance of source rock samples are integrated, and the characteristics of hydrocarbon source rocks in the study area are preliminarily understood. The organic matter types of the source rocks in the two wells are mainly mixed type, the kerogen maturity is very high, the organic carbon content is high, and the hydrocarbon generation potential is very low. The comprehensive analysis shows that the source rocks in the present formation are no longer capable of generating and expelling hydrocarbon, and the residual carbon in the formation is mostly dead carbon, but the organic matter abundance is generally evaluated well after the restoration of organic matter abundance. This means that oil and gas have been generated and expelled in large quantities at some stage of the evolution of the source rocks, with the potential to provide gas sources for natural gas hydrates.) according to the gas anomalies recorded during drilling in the TK2 well, Combined with neutron porosity logging curve and core observation, the favorable reservoir section of two wells was screened, and the samples were observed on thin slices, porosity and permeability, and mercury injection. It is concluded that the reservoir space of the two wells is mainly fissures, followed by pores. The fracture zone in the fracture zone, the macroscopic fissure and the microfissure which are not completely filled can improve the reservoir physical property greatly; the contribution of the primary pore to the reservoir physical property can be neglected basically; the dissolution pore also has the bigger improvement function to the reservoir physical property. The whole formation has good reservoir capacity.
【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】：2017
【分类号】：P618.13

【参考文献】