International Open Access Journal Platform

柴达木盆地东坪地区变质岩型基岩气藏岩性控储特征

Characteristics of Reservoir Spaces and the Influence of Lithology on Reservoir Development in the Basement Gas Reservoir of the Dongping Well Block, Qaidam Basin

Environment and Resource / 2026,8(1): 24-38 / 2026-03-02 26 20

View Download PDF

• Authors: 李奕臻¹ 周翊¹ 李瑞琦¹ 魏靖依² 范存辉¹ 贾正良³ 杨欣¹
• Information:

  1．西南石油大学地球科学与技术学院，成都；
  2．中国石油管理干部学院，北京；
  3．中国石油青海油田勘探开发研究院，敦煌

• Keywords:
  Qaidam Basin; Dongping area; Basement gas reservoir; Metamorphic rock reservoir; Reservoir space; Lithological control on reservoir
  柴达木盆地; 东坪地区; 基岩气藏; 变质岩储层; 储集空间; 岩性控储
• Abstract: The Dongping area has become an exploration hotspot due to the discovery of China’s first metamorphic rock-type bedrock gas reservoir. This region also serves as one of the key targets for natural gas exploration in the eastern segment of the Altun piedmont within the Qaidam Basin. However, systematic research on the characteristics and controlling factors of its bedrock reservoirs remains relatively limited at present. Based on core observations and thin-section identification, combined with whole-rock Xray diffraction analysis, scanning electron microscopy microanalysis, statistical calculations of surface porosity–fracture ratio, and analysis of conventional logging data, this study conducts an indepth investigation into the lithological characteristics, reservoir space features, and their influence on reservoir development of the bedrock gas reservoir in the Dongping area of the Qaidam Basin. The results indicate that the bedrock reservoir rocks in the Dongping area are mainly composed of ortho-metamorphic rocks, including granitic gneiss and plagioclase gneiss, as well as para-metamorphic rocks such as quartz schist, calcareous gneiss, slate, calcareous schist, and metamorphic limestone. The reservoirs are of fracturepore type, with an average porosity of about 2.5% and an average permeability of approximately 0.02 mD. Among the ortho-metamorphic rocks, granitic gneiss represents the favorable reservoir lithology, whose reservoir space is primarily derived from tectonic fractures formed in brittle minerals such as quartz and feldspar under structural stress. In para-metamorphic rocks, slate is the favorable reservoir lithology, and its reservoir quality mainly benefits from dissolution pores, vugs, and fractures developed in easily soluble carbonate minerals dominated by calcite. The findings of this research provide important guidance for further exploration of the bedrock gas reservoir in the Dongping area. 东坪地区因发现我国首个变质岩型基岩气藏而成为勘探热点，该区域亦是柴达木盆地阿尔金山前东段天然气勘探的核心靶区之一，但现阶段关于其基岩储层特征及主控因素的系统性研究仍较为欠缺。在岩心观察、薄片鉴定的基础上，结合全岩X射线衍射分析、扫描电镜微观分析、样品面孔-缝率计算统计和常规测井资料分析，本研究对柴达木盆地东坪地区基岩气藏岩性特征、储集空间特征及其对储层发育的影响进行了深入研究。结果表明，东坪地区基岩储层岩石类型主要为花岗片麻岩、斜长片麻岩两类正变质岩和石英片岩、钙质片麻岩、板岩、钙质片岩、变质灰岩等副变质岩。储层为裂缝-孔隙型，储层平均孔隙度在2.5%左右，平均渗透率在0.02mD左右。正变质岩中储层优质岩性是花岗片麻岩，储集空间主要来自石英、长石等脆性矿物因构造应力而形成的构造缝；副变质岩中储层优质岩性为板岩，储集性能主要得益于以方解石为主的易溶性碳酸盐矿物发育的溶蚀孔、洞和溶蚀缝。该研究成果对指导东坪地区基岩气藏下一步勘探具有重要指导意义。
• DOI: https://doi.org/10.35534/er.0801004 (registering DOI)
• Cite: 李奕臻，周翊，李瑞琦，等．柴达木盆地东坪地区变质岩型基岩气藏岩性控储特征［J］．环境与资源，2026，8（1）：24-38.