以塔里木盆地和四川盆地多层段发育的礁滩体解剖为例，研究不同类型礁滩储集层孔隙成因和非均质性，分析其有效储集层分布规律。礁滩储集层可分为生物礁和颗粒滩两大类：前者与生物格架有关，多形成镶边台缘，可细分为台缘生物礁和台内生物礁储集层；后者与生物格架无关，在缓坡型碳酸盐台地多受海平面升降控制，由滩体迁移形成广布的颗粒滩，在陡坡环境有台缘颗粒滩和台内颗粒滩之分。礁滩体储集空间主要形成于同生期和埋藏期两个阶段，同生期孔隙受原岩骨架和与层序界面有关的溶蚀作用控制，而埋藏期孔隙发育和分布则与同生期孔隙发育和分布密切相关，具有继承性。礁滩储集层具强烈非均质性，有效储集层分布比较复杂，对礁体而言，向上变浅旋回顶部的台缘礁和与礁共生的生物滩是孔隙发育主体，独立滩体向上变浅旋回顶部发育的颗粒滩也是孔隙发育主体，且与致密层间互分布。总体而言，颗粒滩储集层规模大于且物性好于生物礁储集层。图11表2参29%Taking reef-shoal bodies developed in multiple formations in the Tarim Basin and Sichuan Basin as examples, this paper examines the origin of pores and heterogeneity of types of reef-shoal reservoirs, and tries to find out the distribution rules of various reef-shoal reservoirs. Reef-shoal reservoirs can be classified into two main types, i.e. biohermal reservoirs and grain shoal reservoirs. The former, related to reef framework, in the form of frilled platform margin, can be subdivided into interior platform reef complex and margin reef complex (sedimentary or tectonic origin). The latter, not related to reef framework, is controlled by the fluctuation of sea level on gentle slope carbonate platform, is widely developed on carbonate ramp due to the migration of shoal, and can be subdivided into interior platform shoal and platform-margin shoal on steep slopes. Reservoir space of reef-shoal carbonates was primarily formed during syngenetic and burial stages. Syngenetic porosity is controlled by original rock fabric and dissolution related to the exposure of sequence boundaries, while porosity development and distribution in burial stage is closely related to that in syngenetic stage, showing inherited features. Reef-shoal reservoirs are strongly heterogeneous, and complicated in effective reservoir distribution. Platform margin reef and biohermal shoal coexisting with reef on the top of shallowing upward sequence are main reservoirs rich in pores, the grain shoal deposited on top of shallowing upward cycle of isolated reef is also the main zone rich in pores, which usually interbeds with tight reservoir. Overall, grain shoal reservoirs are bigger in scale and better in physical properties than biohermal reservoirs.
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