川北大安寨段储层深部热水溶蚀作用

DEEP HYDROTHERMAL DISSOLUTION OF DA'ANZHAI RESERVOIRS IN NORTH SICHUAN

川北大安寨段灰岩非常规储层的形成与多期次深部热水溶蚀作用密切相关。湖滩及湖坡相带是最有利的深部热水溶蚀作用发育部位，半深湖相区泥质油源岩在不同演化阶段排出的流体是溶蚀流体的主要来源，燕山晚期～喜山早期的频繁溶蚀作用则是该储层的主要形成期。深部热水溶蚀作用可划分为成岩期、构造期、构造期后３个溶蚀期次和５个次生矿物充填阶段，各期次溶蚀孔洞缝的产状，充填物的阴极发光、地球化学、包裹体、有机岩石学和流体性质等特征均有明显的差异，综合这些特征，提出了大安寨段非常规储层的深部热水溶蚀成因模式。

The formation of Da'anzhai limestone reserviors are closely related to multi-stage deephydrothermal dissolution. Lake beach and lakeside factes are most favourable for the development of the dissolution;the fluid that exuded by argillaceous source rocks of semi-deep lacustrine factes during different evolution stage6 is the primary solution source;Late YenshanEarly Himalayan period is the main formation stage of the reservoirs due to frequent dissolution. The deep hydrothermal dissolution could be divided into diagenetic, tectonic and postdiagenetic stages and five secondary mineral filling substages. It is pointed out that the occurrences of the pores,caves and fractures, the cathodoluminescence of the filling minerals, thegeochemical properlies,the inclosions,lithologic and fluid characters of different stages differdifferently. Based on the above mentioned, a model of deep hydrothermal dissolution inDa,anzhai abnormal limestone reservoirs is proposed in this paper.