Hydrocarbon accumulation conditions and exploration potential of the Jurassic coal measure gas in Junggar Basin
Two sets of coal seams are widely distributed in the Jurassic Xishanyao and Badaowan formations in Junggar Basin,and there are abundant coal measure gas resources.However,as a completely new field of natural gas,the level of basic research is low,and gas accumulation characteristics,enrichment laws and resource scale in the basin are unclear.In 2020,a risk exploration well CT1H was drilled to explore gas bearing property of deep coal rocks,and a maximum daily gas rate of 5.7×104m3/d was tested,as well as a steady gas rate of 2×104m3/d in trial production,confirming the high and steady production capacity of coal measure gas.A systematic study on coal rock petrological characteristics,reservoir performance,evolution characteristics and control factors for gas accumulation in coal measure strata has been conducted,which indicates that the thermal evolution degree of coal rocks is low,with a medium-low coal rank,and the coal reservoir in Xishanyao Formation is dominated by meso-macro pores,while that in Badaowan Formation is mainly micro-small pores;By combining with multiple factors controlling gas accumulation in coal measure strata,such as source rock,structure,coal reservoir,and abnormal gas logging shows,the potential fields of coal measure gas in the basin have been classified and evaluated.Two favorable exploration areas including Dinan-Baijiahai and Qigu areas have optimally been selected,and coal measure gas resources are more than 1×1012m3 with a burial depth of 2000-4000 m.
万方数据
维普
