准噶尔盆地南缘西山窑组与八道湾组煤层气成藏富集条件对比研究

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...

Comparative study of CBM accumulation conditions between the Xishanyao Formation and the Badaowan Formation in the southern Junggar Basin

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.