准噶尔盆地东部隆起煤层气成藏条件与选区评价

Accumulation conditions and target area evaluation of coalbed methane in eastern uplift of Junggar Basin

余琪祥 田蜜 罗宇 杨帆 陈彦鄂 王烽 高玉巧 郭涛

YU Qixiang TIAN Mi LUO Yu YANG Fan CHEN Yan'e WANG Feng GAO Yuqiao GUO Tao

1. 中国石化 石油勘探开发研究院 无锡石油地质研究所, 江苏 无锡 214126; 2. 中国石化 油气成藏重点实验室, 江苏 无锡 214126; 3. 中国石化 华东油气分公司 勘探开发研究院, 南京 210094

1. Wuxi Research Institute of Petroleum Geology, SINOPEC, Wuxi, Jiangsu 214126, China; 2. Key Laboratory of Petroleum Accumulation Mechanisms, SINOPEC, Wuxi, Jiangsu 214126, China; 3. Exploration and Development Research Institute, SINOPEC East China Oil and Gas Company, Nanjing, Jiangsu 210094, China

准噶尔盆地东部隆起具有较好的煤层气勘探前景，开展煤层气选区与评价，将为该区煤层气勘探提供科学依据和勘探方向。利用探井钻测录试资料、岩心分析测试数据和地震资料，开展井—震标定和地震剖面解释，编制了侏罗系八道湾组和西山窑组煤层连井剖面和煤层厚度分布图；分析了研究区内煤层气气源、煤岩基本特征、储层物性、含气性和保存条件等成藏主控因素。研究表明：①西山窑组煤层在沙奇凸起以北五彩湾凹陷—梧桐窝子凹陷连片分布，在沙奇凸起以南则主要分布于吉木萨尔凹陷—吉南凹陷；八道湾组煤层分割性较强，主要分布于凹陷内部分地区。②区内存在自源型煤层生物成因气、低成熟热成因气和深部外源型高成熟气条件。③煤岩有机组分以惰质组为主，镜质组次之，壳质组少量；煤岩镜质组反射率低(0.39%～0.47%)，为低煤级煤；煤岩瓦斯气体成分主要为N2、CO2和CH4，其中N2占绝对优势；煤岩总含气量中可燃气体(CH4)含量低。④煤层气富集成藏模式分为山前断陷富集成藏模式、深部凹陷富集成藏模式和开放斜坡逸散模式。⑤建立了煤层气评价参数和划分标准，五彩湾凹陷、梧桐窝子凹陷、吉木萨尔凹陷和吉南凹陷为煤层气勘探有利区；沙帐断褶带和石钱滩凹陷为较有利区；石树沟凹陷和古城凹陷为不利区。

The eastern uplift of the Junggar Basin has great coalbed methane (CBM) exploration potential. CBM selection and evaluation will provide scientific guidance and direction for CBM exploration in the region. Utilizing well logging data, core analysis test results, and seismic data, well-seismic calibration and seismic profile interpretation were carried out. Connecting-well profiles and thickness distribution maps for coal seams in the Jurassic Xishanyao and Badaowan formations were compiled. The study analyzed main accumulation factors, including gas source, basic characteristics of coal rocks, reservoir physical properties, gas content, and preservation conditions. The results show that: ① Coal seams of the Xishanyao Formation are distributed continuously in the Wucaiwan-Wutongwozi sags to the north of the Shaqi Uplift, while to the south of the Shaqi Uplift, the seams are mainly distributed in the Jimusaer-Jinan sags. Coal seams of the Badaowan Formation are strongly segmented and mainly distributed in parts of the sags. ② This region contains self-sourced biogenic gas from coal seams, low-maturity thermogenic gas, and high-maturity deep-seated exogenous gas. ③ The organic components in coal rocks are mainly inertinite, followed by vitrinite with small amounts of exinite. The vitrinite reflectance (Ro) in coal rocks is low (0.39%-0.47%), indicating low-rank coal. CBM mainly consists of N2, CO2, and CH4, with N2 being the dominant component. The combustible gas (CH4) content is low relative to the total gas content in coal rocks. ④ CBM enrichment and accumulation models include piedmont fault depression, deep depression, and open slope gas escape models. ⑤ Evaluation parameters and classification standards were established. The Wucaiwan, Wutongwozi, Jimusaer, and Jinan sags are favorable areas for CBM exploration. The Shazhang fault-fold belt and the Shiqiantan Sag are moderately favorable areas. The Shishugou and Gucheng sags are unfavorable areas.

中国石化科技部项目(P21086-5，P24235)资助。

https://doi.org/10.11781/sysydz2025010117