油气藏评价与开发 ›› 2024, Vol. 14 ›› Issue (6): 959-966.doi: 10.13809/j.cnki.cn32-1825/te.2024.06.018

• 综合研究 • 上一篇    下一篇

贵州六盘水煤田构造煤储层特征与煤层气勘探开发方向

邱文慈1(), 桑树勋1,2,3(), 郭志军4,5, 韩思杰2,3, 周效志1, 周培明4,5, 吴章利4,5, 桑国蕴1, 张斌斌3, 高为6   

  1. 1.中国矿业大学资源与地球科学学院,江苏 徐州 221116
    2.中国矿业大学江苏省煤基温室气体减排与资源化利用重点实验室,江苏 徐州 221008
    3.中国矿业大学碳中和研究院,江苏 徐州 221008
    4.复杂构造区非常规油气勘探开发重点实验室,贵州 贵阳 550081
    5.贵州省油气勘查开发工程研究院,贵州 贵阳 550081
    6.贵州省煤层气页岩气工程技术研究中心,贵州 贵阳 550081
  • 收稿日期:2023-12-18 发布日期:2024-12-10 出版日期:2024-12-26
  • 通讯作者: 桑树勋 E-mail:1511788501@qq.com;shuxunsang@163.com
  • 作者简介:邱文慈(1999—)女,硕士研究生,主要研究方向为煤层气地质、CO2封存等。地址:江苏省徐州市泉山区中国矿业大学,邮政编码:221116。E-mail: 1511788501@qq.com
  • 基金资助:
    国家自然科学基金项目“煤系气高效勘探开发的岩石力学地层理论方法体系研究”(42030810);江苏省创新支撑计划国际科技合作“一带一路”创新合作项目“非常规天然气资源潜力与勘探开发技术模式的合作研究”(BZ2022015);贵州省地质勘查基金项目“毕节试验区煤层气资源调查评价与开发技术研究”(52000021MGQSE7S7K6PRP);安徽省公益性地质工作项目“两准矿区重点区域煤层气储层可改造性调查评价”(2023-sj-13)

Characteristics of stratified coal reservoirs in Liupanshui coalfield of Guizhou Province and exploration and development direction of coalbed methane

QIU Wenci1(), SANG Shuxun1,2,3(), GUO Zhijun4,5, HAN Sijie2,3, ZHOU Xiaozhi1, ZHOU Peiming4,5, WU Zhangli4,5, SANG Guoyun1, ZHANG Binbin3, GAO Wei6   

  1. 1. School of Resources and Geosciences, China University of Mining and Technology, Xuzhou, Jiangsu 221116, China
    2. Jiangsu Key Laboratory of Coal-based Greenhouse Gas Control and Utilization, China University of Mining and Technology, Xuzhou, Jiangsu 221008, China
    3. Carbon Neutrality Institute, China University of Mining and Technology, Xuzhou, Jiangsu 221008, China
    4. Key Laboratory of Unconventional Oil and Gas Exploration and Development in Complex Structural Areas, Guiyang, Guizhou 550081, China
    5. Guizhou Engineering Research Institute of Oil & Gas Exploration and Development, Guiyang, Guizhou 550081, China
    6. Guizhou Provincial Engineering and Technology Research Center of Coalbed Methane and Shale Gas, Guiyang, Guizhou 550081, China
  • Received:2023-12-18 Online:2024-12-10 Published:2024-12-26
  • Contact: SANG Shuxun E-mail:1511788501@qq.com;shuxunsang@163.com

摘要:

贵州省煤层气资源丰富,但构造煤的发育制约了煤层气增储上产,通过研究贵州构造煤储层特征,在此基础上提出了可适配的勘探开发技术,为提高贵州构造煤储层资源的安全、高效开发技术水平提供了理论基础。在煤层力学性质非均质性和构造应力场不均匀分布的控制下,构造煤分层现象更为普遍。以六盘水煤田大河边向斜11号煤层为例,开展等温吸附、压汞、低温液氮、低温CO2吸附实验,研究了各分层储层物性特征,讨论了厚煤层构造煤分层形成机制及煤层气富集模式,比较了复杂煤体结构厚煤层煤层气适配性勘探开发技术及其适用性。研究表明:①大河边向斜11号煤层平均厚度为4.48 m,厚煤层的形成是盆地沉降速率和物源沉积补偿平衡的结果,在后期挤压和推覆构造作用下,11号煤层出现挤压、破碎甚至层间滑动,构造煤分层开始发育,中部分层应力集中且煤岩力学性质偏弱;②11号煤层在垂向上发育“三明治”特征,自上而下分别为原生结构煤、糜棱煤和碎裂煤;③中部煤储层的微孔比例最高,吸附能力最强,最大吸附量的兰氏体积呈现出中分层(16.55 cm3/g)>下分层(14.69 cm3/g)>上分层(13.96 cm3/g)的规律;④研究区11号煤层形成岩性-断层-水力封堵型气藏,针对煤体结构分层特征对比分析了3种不同的开发技术路线,提出适用性最强的水平井构造煤软分层造穴卸压煤层气开发方向。

关键词: 构造煤分层, 煤层气, 厚煤层, 储层特征, 勘探开发方向

Abstract:

Guizhou Province is rich in coalbed methane(CBM) resources; however, the development of tectonic coal constrains the increase of reserves and production. By studying the reservoir characteristics of tectonic coal in Guizhou, adaptable exploration and development technologies are proposed, providing a theoretical basis for the safe and efficient development of tectonic coal reservoirs in the province. Under the control of the heterogeneous mechanical properties of coal seams and the uneven distribution of tectonic stress fields, the phenomenon of stratification in tectonic coal is more prevalent. Taking the No. 11 coal seam in the Dahebian syncline of the Liupanshui Coalfield as an example, isothermal adsorption, mercury intrusion, low-temperature liquid nitrogen adsorption, and low-temperature CO2 adsorption experiments were conducted to study the physical properties of each stratified reservoir. The formation mechanism of tectonic coal stratification in thick coal seams and the CBM enrichment pattern were discussed. The adaptability and applicability of exploration and development technologies for CBM in thick coal seams with complex coal structures were compared. The results showed that:1) The average thickness of the No. 11 coal seam in the Dahebian syncline was 4.48 m, and the formation of thick coal seams was the result of a balance between basin subsidence rates and sedimentary supply. Under subsequent compressional and thrust tectonic activities, the No. 11 coal seam underwent compression, fracturing, and even interlayer sliding, leading to the development of stratification in tectonic coal. Stress was concentrated in the middle stratification, where the mechanical properties of the coal were weaker. 2) The No. 11 coal seam exhibited a “sandwich” structure in the vertical direction, consisting of primary structural coal on top, mylonitic coal in the middle, and fragmented coal at the bottom. 3) The middle coal reservoir had the highest proportion of micropores and the strongest adsorption capacity. The Langmuir volume of maximum adsorption followed the trend: middle stratification(16.55 cm³/g) > lower stratification(14.69 cm³/g) > upper stratification(13.96 cm³/g). 4) The No. 11 coal seam in the study area formed a lithology-fault-hydraulic seal gas reservoir. Based on the stratified characteristics of the coal structure, three different development technology routes were compared, and the most applicable direction for CBM development was identified as constructing cavities in the soft stratification of tectonic coal using horizontal wells to achieve pressure relief and CBM extraction.

Key words: tectonic coal stratification, coalbed methane, thick coal seam, reservoir characteristics, exploration and development direction

中图分类号: 

  • TE37