川西泥盆系观雾山组沉积相研究缺乏横向对比,沉积模式还存在争议.根据川西北部白家乡大木垭剖面与何家梁剖面实测成果,对中泥盆统观雾山组沉积相进行了分析,认为:大木垭剖面与何家梁剖面观雾山组为碳酸盐镶边台地沉积,期间发生短暂的碳酸盐缓坡化;桂溪剖面观雾山组同属碳酸盐台地边缘,观雾山组中段发育开阔台地深水沉积,并不是前人认为的潟湖沉积.研究区碳酸盐镶边台地包括台地边缘和前缘斜坡两种亚相,前缘斜坡亚相发育于何家梁剖面,以塌积岩沉积为标志.碳酸盐缓坡包括深水缓坡和浅水缓坡两种亚相.随着海平面变化,观雾山组碳酸盐岩发育三个沉积旋回,第一、第三沉积旋回为镶边台地沉积,第二沉积旋回为碳酸盐缓坡沉积.观雾山组沉积微相对储层的分布起控制作用:生物碎屑滩和上斜坡微相为有利储层发育相带;生物礁中在油气运移之前形成的溶蚀孔洞已被白云石和方解石充填,滩间微相泥质(泥晶)白云岩不利于溶蚀孔洞形成,这二者均不是有利储层发育相带.

Due to the lack of horizontal comparison in carbonate facies, the sedimentary model of the Middle Devonian Guanwushan Fm. was still in dispute. Based on the field work, facies of Guanwushan Fm. in Damuya and Hejialiang were analyzed. It is suggested that the strata was dominated by rimmed carbonate platform with a short period of carbonate ramp. Guanwushan Fm. in Guixi was under the same sedimentary conditions, while not the lagoon facies. Influenced by the sea level change, three sedimentary cycles were developed. The first cycle and the third cycle were both characterized by rimmed platform deposits, while the second cycle developed carbonate ramp. Microfacies controlled the distribution of dolomite reservoir in Guanwushan Formation. Debris beach and upper slope are favorable facies, while platform edge reef and intra-beach are not favorable, especially the karst-caves formed before the migration of hydrocarbon were usually filled by dolomite and calcite.