摘要
为了加快准噶尔盆地南缘(准南)西山窑组煤层气勘探开发进程,针对该地区侏罗系八道湾组和西山窑组煤层气成藏条件差异,开展了准南西山窑组与八道湾组煤层气成藏富集条件对比研究。结果表明,受成煤期古气候和沉积环境的影响,八道湾组煤层具有较高的镜质组含量,而西山窑组则具有较高的惰质组含量;受控于煤级的影响,准南八道湾组煤的微孔含量和比表面积高于西山窑组;八道湾组和西山窑组煤储层构造裂隙数量明显高于内生裂隙,且裂隙发育密度与煤层所处的构造位置关系密切;基于煤岩、煤厚、盖层、水文地质条件分析,整体上八道湾组煤层含气量高于西山窑组,但西山窑组煤层气的直接盖层条件要优于八道湾组。以乌鲁木齐河西区为例,提出了对冲褶皱型煤层气成藏富集模式,认为逆断层封堵的单斜、浅部中和面以下的向斜斜坡带以及深部背斜轴部地带是准南地区西山窑组潜在的煤层气富集区。该研究成果认识,对于丰富和完善我国低煤阶煤层气成藏富集理论具有一定的指导意义。
In order to accelerate the process of CBM exploration and development for the Xishanyao Formation in the southern Junggar Basin,a comparative study of CBM accumulation and enrichment conditions between the Jurassic Xishanyao Formation and the Badaowan Formation was carried out.The results show that the coals in the Badaowan Formation have relatively high vitrinite contents influenced greatly by paleoclimate and sedimentary environment during the coal-accumulative period,whereas obvious great inertinite contents are existed in the coals form the Xishanyao Formation.Due to various coal ranks,the micropore contents and specific surface area of coals in the Badaowan Formation are relatively higher than those in the Xishanyao Formation.It is found that the density of the deformed fractures in the coal reservoirs is more developed than that of the endogenous fractures,and the develop of the deformed fracture is closely related with the structural locations of the coals.Based on the analyses of coal maceral,coal thickness,sealing and hydrogeological conditions,the gas contents of the coals from the Badaowan Formation are higher than that in the Xishanyao Formation,whereas the direct seal-capping of the Xishanyao CBM is superior to that of the Badaowan gas.Taking the western Urumqi River for an example,ramp-fold structure for CBM accumulation model has been proposed,and the zones of the monocline sealed by reverse fault,the shallow slop zone in syncline and the deep axis in anticline are the potential CMB enrichment areas in the Jurassic Xishanyao coals,southern Junggar Basin.The above achievements have certain guiding significance to enrich the theory of low rank CBM accumulation in China.
作者
侯海海
李强强
梁国栋
秦秋红
张华杰
刘书君
HOU Haihai;LI Qiangqiang;LIANG Guodong;QIN Qiuhong;ZHANG Huajie;LIU Shujun(College of Mining, Liaoning Technical University, Liaoning Fuxin 123000, China)
出处
《非常规油气》
2022年第1期18-24,共7页
Unconventional Oil & Gas
基金
中国地质调查局科研项目“准南侏罗系煤层气富集条件与控制因素研究”(DD20160204)
中国博士后科学基金资助项目“煤储层全尺度孔裂隙系统定量表征及对煤层气运移的影响机理”(2021M693844)。
关键词
准南
低煤阶
成藏模式
水文地质
勘探方向
southern Junggar Basin
low rank
CBM enrichment model
hydrogeological condition
explorative prospects
