煤田地质与勘探2026，Vol.54Issue(4)：95-111,17.DOI:10.12363/issn.1001-1986.26.01.0048
准南米泉地区侏罗系煤层气地质特征及富集成藏模式
Geological characteristics and enrichment-accumulation patterns of coalbed methane within the Jurassic strata in the Miquan area along the southern margin of the Junggar Basin
摘要
Abstract
[Objective]The southern margin of the Junggar Basin(also referred to as the southern Junggar)possesses abundant medium-to low-rank coalbed methane(CBM)resources,with significant progress achieved in CBM explora-tion and production.However,there remains a lack of systematic understanding of the genetic mechanisms of CBM within the Middle-Lower Jurassic strata,along with its accumulation and evolution laws,in the Miquan area,southern Junggar.This absence restricts the commercial development of CBM in these strata.[Method]Focusing on CBM with-in the Middle-Lower Jurassic Xishanyao and Badaowan formations in the Miquan area,this study further identified the CBM origins and characterized the CBM accumulation patterns in detail.Using the Petromod basin modeling software,this study simulated the geological evolution process of the Jurassic coal seams and elucidated CBM enrichment and ac-cumulation laws.Accordingly,it established and improved the CBM accumulation patterns of the Jurassic strata in the Miquan area.[Results and Conclusions]In the Miquan area,the CBM within the Xishanyao Formation is dominated by secondary biogenic gas,while that in the Badaowan Formation consists of thermogenic gas formed after modification by microbial degradation(similar to the Fukang block).Laterally,the Badaowan syncline exhibits a significantly higher gas content(6.62 m3/t)than the Northern monocline(5.40 m3/t).Vertically,there is a negative correlation between gas con-tent and methane concentration.Specifically,with increasing coal seam burial depth,the gas content trended upward,while the methane concentration showed a decreasing trend.Further investigation reveals that the CBM accumulation evolution in the Miquan area can be divided into five key stages:the generation and dissipation of primary biogenic gas during the Early-Middle Jurassic(199-163 Ma);the generation of secondary biogenic gas in the Xishanyao Formation during the Middle-Late Jurassic(163-135 Ma);the generation of thermogenic gas in the Badaowan Formation during the Cretaceous(135-78 Ma);the continuous recharge of thermogenic gas in the Badaowan Formation during the Late Cretaceous-Oligocene(78-23 Ma),and the recharge of secondary biogenic gas and the modification of thermogenic gas since the Neogene(23 Ma to present).The control and enrichment laws of CBM within the Jurassic strata in the Miquan area were also revealed,characterized by syncline-controlled enrichment,structure-controlled accumulation,and hydro-dynamic sealing.Accordingly,three accumulation pattern types were established:Badaowan syncline-fault type,the Qidaowan anticline-fault-lithologic trap type,and the hydrodynamic sealing type of steeply inclined coal seams in the Northern monocline.The results of this study can provide a reference for understanding the genetic mechanisms and de-veloping exploration schemes of other medium-to low-rank CBM.关键词
煤层气成因/中低煤阶/富集成藏/米泉地区/准噶尔盆地南缘Key words
origin of coalbed methane(CBM)/medium and low coal ranks/enrichment and accumulation/Miquan area/southern margin of the Junggar Basin分类
天文与地球科学引用本文复制引用
吴洛菲,王小明,杨康军,张杰,石永霞,伏海蛟,杨曙光,王刚,刘蒙蒙,李跃国..准南米泉地区侏罗系煤层气地质特征及富集成藏模式[J].煤田地质与勘探,2026,54(4):95-111,17.基金项目
新疆维吾尔自治区重大科技专项(2023A01004-2) （2023A01004-2）
中联煤层气有限责任公司重点科技项目(202513688445) （202513688445）
国家自然科学基金面上项目(42172192) （42172192）
新疆维吾尔自治区科技创新领军人才项目(2023TSYCLJ0005) （2023TSYCLJ0005）
新疆维吾尔自治区重点研发计划项目(2024B01017-3). （2024B01017-3）
