Petrochina Research Institute of Petroleum Exploration & Development
College of Geology and Mining Engineering, Xinjiang University
Exploration and Development Research Institute, PetroChina Tuha Oilfield Company

富油煤是焦油产率≥7%且具备煤、油、气属性的特殊煤炭资源，是煤炭清洁利用的重要资源和开发方向，对缓解国家油气资源紧缺、推动煤化工突破性发展具有重要的科学价值。新疆东部盆地蕴藏着大量富油煤资源，为探明富油煤的赋存特征与分布规律，通过沉积环境分析，结合煤工业分析、元素分析、格金低温干馏测试等手段研究东疆富油煤聚煤规律与赋存特征，采用地质块段法估算富油煤资源量。结果表明：三塘湖盆地富油煤层主要分布于八道湾组上段(J1b2)、三工河组(J1s)以及西山窑组下段(J2x1)3个层位，焦油产率约13.67%，总体属高油煤；吐哈盆地富油煤发育在西山窑组中段(J2x2)，焦油产率约7.6%，总体为含−富油煤。区内富油煤总体特征为特低−中低水分、低−中低灰分、中高−高挥发分，焦油产率高，富含镜质组和壳质组等生油组分，煤化程度低，形成于湖泊−三角洲的沉积环境。研究区富油煤资源潜力大，估算三塘湖盆地2 000 m以浅的富油煤资源量约670.83亿t，吐哈盆地2 000 m以浅的富油煤资源量约417.55亿t，可采煤层平均厚度达9 m以上。为有效动用富油煤资源，提出煤炭地下干馏的技术设想，即通过石油工程技术在地下煤层建立热量导入和产品产出通道，通过人工加热方式使煤原位发生干馏反应，热解产物包括焦油、煤气(CH4、H2、轻烃C2+等)、水等，煤中的碳元素主要以半焦形式留在地下，产生的二氧化碳可为三塘湖−吐哈盆地的油田提供气驱气源，剩余的二氧化碳可以利用半焦层原位埋存。煤炭地下干馏通过“取氢留碳”实现煤炭资源清洁转化，有望成为富油煤低碳绿色开发的重要技术方向。

Oil-rich coal is a special coal resource with a tar yield ≥ 7% and a combination of coal, oil, and gas attributes. It is an important resource and development direction for the clean utilization of coal, and has important scientific value in alleviating the shortage of national oil and gas resources and promoting the breakthrough development of coal chemical industry. There are a large number of tar-rich coal resources in the eastern basin of Xinjiang Uygur Autonomous Region. In order to find out the occurrence and distribution of tar-rich coal, the coal accumulation and occurrence characteristics of tar-rich coal were studied by means of sedimentary environment analysis, proximate analysis of coal, ultimate analysis of coal, and Gray-King assay for coal. The geological block method was used to estimate the resources of tar-rich coal. The results show that the tar-rich coal seams in the Santanghu Basin are mainly distributed in the upper section of the Badaowan Formation (J1b2), the Sangonghe Formation (J1s) and the lower section of the Xishanyao Formation (J2x1), the tar yield is about 13.67%, which is high tar-rich coal. The tar-rich coal seams in the Turpan-Hami Basin are developed in the middle section of the Xishanyao Formation (J2x2), and the tar yield is about 7.6%, which are tar-bearing coal and tar-rich coal. The tar-rich coal in the area is generally characterized by ultra-low to medium-low water content, low to medium-low ash content, medium-high to high volatile content, high tar yield, rich in oil generating components such as vitrinite and lipitnite, low degree of coalification, and formed in the lacustrine-deltaic sedimentary environment. The potential of rich oil coal resources in the study area is large. The resources of tar-rich coal in the Santanghu Basin is estimated to be 67.083 billion tonnes above a depth of 2 000 m, and the resources of tar-rich coal in the Turpan-Hami Basin is estimated to be 41.755 billion tonnes above a depth of 2 000 m, and the average thickness of the coal seams is more than 9 m. In order to effectively utilize the development of oil rich coal resources, the technical assumption of Underground Coal Pyrolysis (UCP) is proposed. The UCP refers to the establishment of heat introduction and product production channels in underground coal seams through petroleum engineering technology. Through artificial heating, coal undergoes in-situ carbonization reactions. The pyrolysis products include tar, gas (CH4, H2, light hydrocarbon C2+, etc.), and water. The carbon element in coal is mainly left underground in the form of semicoke, and the generated carbon dioxide can be used to drive oil in the Santanghu and Turpan-Hami Basins. The remaining carbon dioxide can be buried in-situ using the semicoke layer. The UCP achieves a clean conversion of coal resources through “hydrogen extraction and carbon retention”, which is expected to become a technical direction for the low-carbon green development of tar-rich coal.

中国石油天然气股份有限公司重大科技攻关资助项目(2019E-25)

东振，张梦媛，陈艳鹏，等. 三塘湖−吐哈盆地富油煤赋存特征与资源潜力分析[J]. 煤炭学报，2023，48(10)：3789−3805.

DONG Zhen，ZHANG Mengyuan，CHEN Yanpeng，et al. Analysis on the occurrence characteristics and resource potential of tar-rich coal in Santanghu and Turpan-Hami Basins[J]. Journal of China Coal Society，2023，48(10)：3789−3805.