石油学报 ›› 2023, Vol. 44 ›› Issue (11): 1781-1790.DOI: 10.7623/syxb202311003

• 地质勘探 • 上一篇    下一篇

深部超饱和煤层气藏概念及主要特点

康永尚1,2, 闫霞3, 皇甫玉慧4, 张兵5, 邓泽6   

  1. 1. 中国石油大学(北京)地球科学学院 北京 102249;
    2. 油气资源与工程全国重点实验室, 中国石油大学(北京) 北京 102249;
    3. 中联煤层气国家工程研究中心有限责任公司 北京 100095;
    4. 北京大学地球和空间科学学院 北京 100871;
    5. 中联煤层气有限责任公司 北京 100015;
    6. 中国石油勘探开发研究院 北京 100083
  • 收稿日期:2023-06-30 修回日期:2023-09-21 出版日期:2023-11-25 发布日期:2023-12-08
  • 通讯作者: 康永尚,男,1964年11月生,1991年获法国洛林理工学院博士学位,现为中国石油大学(北京)教授,主要从事非常规油气勘探开发、油气储量及价值评估研究。
  • 作者简介:康永尚,男,1964年11月生,1991年获法国洛林理工学院博士学位,现为中国石油大学(北京)教授,主要从事非常规油气勘探开发、油气储量及价值评估研究。Email:kangysh@sina.com
  • 基金资助:
    中国石油天然气股份有限公司攻关性应用性科技项目(2023ZZ1804)资助。

Concept and main characteristics of deep oversaturated coalbed methane reservoir

Kang Yongshang1,2, Yan Xia3, Huangfu Yuhui4, Zhang Bing5, Deng Ze6   

  1. 1. College of Geosciences, China University of Petroleum, Beijing 102249, China;
    2. National Key Laboratory of Petroleum Resources and Engineering, China University of Petroleum(Beijing), Beijing 102249, China;
    3. China United Coalbed Methane National Engineering Research Center Co., Ltd., Beijing 100095, China;
    4. School of Earth and Space Sciences, Peking University, Beijing 100871, China;
    5. China United Coalbed Methane Corporation Ltd., Beijing 100015, China;
    6. PetroChina Research Institute of Petroleum Exploration and Development, Beijing 100083, China
  • Received:2023-06-30 Revised:2023-09-21 Online:2023-11-25 Published:2023-12-08

摘要: 通过分析深部超饱和煤层气藏,得到以下认识:①随着煤层的埋深增加到一定深度,煤阶和地层压力对吸附的正向作用小于温度对吸附的负向作用,导致吸附气逐渐达到饱和状态(吸附饱和度为100%)并进入原地游离气赋存阶段,形成深部超饱和煤层气藏;地层压力和温度随埋深增加的客观规律使得盆地深部具备形成超饱和煤层气藏的天然条件。②不同盆地出现超饱和煤层气藏的临界深度不同,超饱和煤层气藏临界深度的差异主要取决于盆地的地温梯度和压力梯度,异常高压和异常高温(如由火山热事件引起的高温)可降低超饱和煤层气藏形成的临界深度。③深部超饱和煤层气藏在开发中具有见气时间短、能充分利用地层能量和累积产水量低等优势,有望成为未来煤层气勘探开发的一个重要领域,在中国大型的、具有深部煤层埋藏条件的盆地中具有广阔勘探前景。深部超饱和煤层气藏的认识来源于对现场静态资料和排采动态资料的解析,体现了认识来源于实践又服务于实践的认识论观点,对于指导深部煤层气勘探开发具有重大意义。

关键词: 深部超饱和, 煤层气, 吸附饱和, 原地游离气, 游离气饱和度

Abstract: Based on the analysis of deep oversaturated coalbed methane (CBM) reservoirs, the following understandings are obtained. (1) As the buried depth of coal seam increases to a certain depth, the positive effect of coal rank and formation pressure on adsorption is less than the negative effect of temperature on adsorption, as result of which the adsorption gas is gradually saturated (adsorption saturation of 100%) and enters in the stage of in-situ free gas occurrence, thus forming deep oversaturated CBM reservoirs. The formation pressure and temperature keep increasing with the buried depth, and this objective law provides natural conditions for the formation of oversaturated CBM reservoirs in deep strata of the basin. (2) The critical depth of oversaturated CBM reservoirs varies in different basins, and the critical depth difference of oversaturated CBM reservoirs is determined by the basin geothermal gradient and pressure gradient. Abnormal high pressure and temperature (such as the high temperature caused by volcanic thermal events) can reduce the critical depth of oversaturated CBM reservoirs. (3) Deep oversaturated CBM reservoirs have the advantages of short gas breakthrough time, full utilization of formation energy and low cumulative water production in the exploitation, which is expected to become an important field of CBM exploration and development in the future, possessing broad exploration prospects in China's large-scale basins with deep coal seam burial conditions. The understandings of deep oversaturated CBM reservoirs come from the analysis of static data and production dynamic data on-site, reflecting the epistemological view that the knowledge originates from practice and in turn serves practice. This has great significance for guiding deep CBM exploration and development.

Key words: deep oversatured reservoir, coalbed methane, adsorption saturation, in-situ free gas, free gas saturation

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