川西北广旺地区飞仙关组沉积岩石学特征及沉积环境分析

Characteristic of Sedimentary Petrography and Depositing Environment of the Feixianguan Fm. in Guangyuan-Wangcang Southwestern Sichuan Province

通过野外剖面、岩芯的观察和室内薄片的鉴定,以成岩作用和沉积环境分析为主线,分析了川西北广元至旺苍地区飞仙关组各种沉积岩的沉积成岩特征和所代表的不同沉积环境。认为广旺地区飞仙关组一段和三段的油气储层的主要岩性是鲕粒灰(云)岩,其次是波状藻叠层白云岩和粉晶白云岩。分析了四种主要岩性的储集性能差异关系(颗粒云岩>波状藻叠层白云岩>颗粒灰岩>粉晶白云岩)及其原因,并勾画出了颗粒灰(云)岩的富集分布区域。最后根据本区沉积岩石学、构造特征、飞一段至飞四段沉积环境演化过程的分析,归纳总结出了川西北广旺地区飞仙关组的沉积环境模式图。

Based on observing the geological sections, drilling cores and identifying the thin slices,the authars stuied the characteristic of sedimentary rocks and depositional environment of the Feixianguan Fro.in GuangyuanWangcang area, northwestern Sichuan Province. It is suggesed that the lithologic character oil/gas reservoir of the Feixianguan Formation 1 and 3 in Ouangyuan-Wangcang district, southwestern Sichuan are mainly ooide limestone and dolomite, secondly, are sinuational algae stack dolomite rock and crystal powder dolomite rocks. And the oil-bearing condition of the four main kinds of rocks is granule dolomite rock 〉 sinuational algae stack dolomite rock 〉 granule limestone rock 〉 crystal powder dolomite rock.They sum up the modal shape of depositional environment of this region.