页岩气“甜点”评价与预测——以四川盆地建南地区侏罗系为例

Evaluation and prediction of shale gas sweet spots:a case study in Jurassic of Jiannan area,Sichuan Basin

该文提出了页岩气"甜点"评价体系、关键步骤及核心参数评价法和标准,并以四川盆地建南地区侏罗系为例,应用该评价体系,研究了页岩气储层"甜点"基本地质特征,预测了"甜点"分布规律,提出了勘探评价井部署井位,并取得了良好的效果。研究表明:1)与常规油气评价不同,非常规页岩气评价及勘探开发需要采用地质与工程一体化评价方法,综合集成地质、地球化学、石油工程、岩石力学和油层物理等多学科的成果,综合评价;2)建页HF-1井长水平段压裂成功显示建南地区侏罗系页岩气具有良好的开发前景;3)制作页岩厚度、ω(TOC)等值线、Ro等值线、页岩埋深等多因素叠合综合分析图件,对页岩气有利"甜点"预测和勘探开发部署具有很好的指导作用。

The evaluation system, critical steps and key parameters for shale gas sweet spots were discussed in this paper. A case study was carried out in Jurassic of Jiannan area of the Sichuan Basin. By means of the evaluation system, the geologic features of sweet spots in shale gas reservoirs were analyzed, the distribution pattern of sweet spots were predicted, and the arrangement of exploration wells were put forward, resulting in good effects. It was concluded as followed. 1 ） Different from conventional petroleum evaluation, the evaluation and exploration of unconventional shale gas demanded an unconventional approach combining geology with engineering. Geology, geochemistry, petroleum engineering, lithomechanics and petrophysics all contributed to the evaluation. 2） The success of long-distance horizontal fracturing in well Jianye HF-1 proved good potential for shale gas exploration in Jurassic of Jiannan area. 3 ） The maps of shale thickness, co （TOC） , Ro and burial depth might guide shale gas sweet spots exploration.