【摘要】 轮南地区中奥陶统含礁层系位于一间房组。生物礁主要类型为 Calathium 障积丘,瓶筐石为最主要的造礁生物。礁体形态多样,规模较小,厚度为2.2～10m。含礁层系储集空间类型较多。储层物性的统计结果显示,礁核、礁盖和礁基的孔隙度平均值分别为1.54%、3.21%和1.70%;渗透率大部分都高于0.1×10^-3μm²,最高值分别为54.4×10^-3μm²、24.66×10^-3μm²和613×10^-3μm²。这表明含礁层系储层物性总体比较差,以低孔隙度/低、中渗透率为特征,但礁基、礁盖的储层物性明显好于礁核。储层类型以裂缝型和裂缝一孔隙型为主,孔隙型储层不发育。导致这种储集物性的原因一方面与礁体沉积相有关,另一方面与胶结作用、溶蚀作用、破裂作用和压实、压溶作用等成岩作用的改造有关。更多还原

【Abstract】 Middle Ordovician Yijianfang reef beds were discovered in Lunnan area,Tarim Basin.The main type of reefs is Calathium bafflestone,in which Calathium is the most important reef- building organism.Yijianfang reef bodies are various in shape, small in size and 2.2～10 m in thickness.Space of reef reser- voirs is varied in types.Analysis of reef reservoirs shows the average porosities of 1.54%,3.21% and 1.70% and the maximal permeability of 54.4×10^-3 μm²,24.66×10^-3μm² and 613×10^-3μm² respectively in reef core,cap and base. The permeability is generally higher than 0.1×10^-3 μm² for most samples.It is indicated that reefs reservoirs are charac- terized by low porosity and low—medium permeability.Statis- tic data has shown that the reservoir properties of rocks in reef base and cap are distinctly better than those of rocks in reef core.The reservoirs are commonly fractured and fracture- pored and the pored reservoirs are seldom developed.It is deemed that such reservoir properties may not only result from sedimentary environments but also diagenesis,such as ce- mentation,solution,fracturing,pressolution and so on.更多还原