四川盆地元坝地区大安寨段储层裂缝预测

Fracture prediction of Daanzhai member in Yuanba area,Sichuan basin

裂缝发育对致密储层的孔渗性改善具有重大作用,是天然气能否富集、产出和高产的主控因素。在实际研究中,采用地震相波形分类技术及钻井资料对元坝地区的大安寨段进行地震沉积相研究,划分出研究区大安寨段的有利储层——浅湖亚相中的介壳滩相分布的大致范围。针对元坝地区大安寨段的裂缝型气藏,采用三维地震相干分析、叠前P波方位各向异性检测等技术方法,对大安寨段中的介壳滩相进行裂缝发育带综合预测及评价,裂缝预测结果与钻井资料吻合较好,揭示该地区介壳滩相中的裂缝区域是今后的油气勘探重点。

As the main controlling factors of gas enrichment and high yield,fracture development is of great importance to the improvement of reservoir porosity of dense.In actual research,the seismic sedimentary facies of the Da'an Zhai member in Yuanba area were investigated on basis of drilling data and by using seismic waveform classification.As a result,not only the shell beach in shallow lake subfacies was found to be the favorable reservoir in Da'an Zhai member of the research area,but also the general distribution area of it was given.Meanwhile,through 3-D seismic coherence analysis and Prestack P-wave anisotropy test,the shell beach facies in Da'an Zhai member was studied on the comprehensive predication and evulation of facture development belts in the fracture reservoir of Da'an Zhai member.The fracture predication results which showed well consistent with drilling data suggested that the fracture area in shell beach would be the exploration focus.