川东北沙溪庙组天然气地球化学特征及地质意义——以五宝场地区为例

川东北地区侏罗系沙溪庙组浅层致密气具有投资成本低、见效快、分布广、资源量大、埋深浅等诸多优势,是一个高效的勘探开发对象.通过对川东北五宝场地区侏罗系沙溪庙组天然气与下伏烃源岩实地采集,进行了相关的天然气组分、碳同位素、镜质体反射率、显微组分以及总有机碳测定等地球化学实验,根据天然气和烃源岩样品分析,对川东北侏罗系沙溪庙...

Geochemical characteristics and geological significance of Shaximiao Formation in northeastern Sichuan Basin:a case study fromWubaochang area

The shallow tight gas of Jurassic Shaximiao Formation in northeastern Sichuan Basin has many advantages,such as low investment cost,quick effect,wide distribution,large amount of resources and shallow burial depth,so it is an efficient exploration and development object.Through the collection of natural gas of Jurassic Shaximiao Formation and underlying source rocks in Wubaochang area of northeastern Sichuan Basin,the natural gas components,carbon isotopes,vitrinite reflectance,microscopic components and total organic carbon content were determined.Combined with analysis of natural gas and source rock samples,the gas source of Jurassic Shaximiao Formation in northeastern Sichuan Basin was discussed.Combined with typical reservoir accumulation section of Shaximiao Formation and the present development degree of tight gas in northeastern Sichuan Basin,the typical reservoir accumulation model of Jurassic Shaximiao Formation in northeastern Sichuan Basin was analyzed.The results show that the natural gas of Jurassic Shaximiao Formation in northeastern Sichuan Basin mainly comes from the underlying lacustrine source rocks of Jurassic Ziliujing Formation and coal measure source rocks of Triassic Xujiahe Formation.The source rocks of Jurassic Ziliujing Formation in northeastern Sichuan Basin are typeⅡ1-Ⅱ2 high mature medium-good source rocks,and the source rocks of Xujiahe Formation are typeⅢover-mature source rocks.The Wubaochang and Dukouhe areas in the front margin of the Daba Mountain in northeastern Sichuan Basin have good conditions for tight gas accumulation,and are the key areas for next shallow tight gas exploration.The exploration should focus on finding favorable zones of Shaximiao Formation,increase the exploration wells of underlying Ziliujing Formation and Xujiahe Formation to obtain more geological data,and expand the exploration and development scope outwards withWubaochang and Dukouhe areas as the center.