渡口河构造珍珠冲段浅层天然气成藏条件分析

RESERVOIRING CONDITION ANALYSIS OF SHALLOW GAS IN ZHENZHUCHONG MEMBER IN DUKOUHE STRUCTURE

渡3井和渡浅1井在侏罗系下统自流井组珍珠冲段(J1z)钻获天然气,为了开辟川东北地区陆相碎屑岩油气勘探的新领域,文章对渡口河构造的特点、珍珠冲段的成藏地质条件进行了分析和探讨,认为渡口河构造珍珠冲段天然气主要来自下伏陆相生烃岩系,分流河道微相具有良好的储集性能,录井、测井、地震资料均表明珍珠冲段砂岩储层发育,纵向上分布较稳定,横向上有一定分布范围;具有较好的封盖条件;提出渡口河构造珍珠冲段浅层气勘探应遵循“兼探为主,专探为辅”的建议。

Natural gas was found out in Zhenzhuchong member, Ziliujing Formation. Lower Jurassic, in wells Du-3 and Duqian-1. In order to open up the new oil and gas exploration target of continental clastic rocks in Northeast Sichuan, through analyzing and investigating the reservoiring geological conditions and characteristics of Zhenzhuchong member in Dukouhe structure, it is pointed out in the paper that the natural gas in Zhenzhuchong member in Dukouhe structure mainly came from underlying continental source rocks and the distributary channel microfacies is of good petrophysical property; and the geological logging, well logging and seismic data indicate that the sandstone reservoirs are developed in Zhenzhuchong member, they having a stable vertical distribution and good sealing condition, and occupying a certain lateral area. Finally, it is suggested that the shallow gas exploration of Zhenzhuchong member in Dukouhe structure should follow the principle of 'relying mainly on simultaneous exploration while making special exploration subsidiary'.