障壁岛及其后缘碳酸盐岩储层的成因模式与预测

塔里木盆地、鄂尔多斯盆地和四川盆地主要碳酸盐岩储层的发育均与障壁岛或其后缘等沉积环境有关,并受早期大气淡水淋滤溶蚀作用、白云石化作用、古岩溶作用以及埋藏溶蚀作用等成岩因素的控制。认为三大盆地碳酸盐岩储层可划分为大气淡水淋溶型礁滩灰岩储层、古岩溶型礁滩灰岩储层、白云石化型礁滩白云岩储层和古岩溶型含膏白云岩储层等四种类型。提出了与障壁有关的储层综合成因与预测模式,其中构成障壁的台地边缘礁滩带是大气淋溶型礁滩灰岩储层、古岩溶型礁滩灰岩储层和白云石化型礁滩白云岩储层的有利发育区,而障壁岛后缘的蒸发盆地边缘坪区域是古岩溶型含膏白云岩储层有利发育区。

Genesis and Prediction Model of Carbonate Reservoir in Barrier Island and Its Back Edge

Genesis and prediction of carbonate reservoirs has been one of the hot spots of petroleum exploration and geology research. It is shown that deposition of carbonate reservoirs is mainly related to the environments of the barrier island and the edge zone behind it and is controlled by the atmosphere fresh water leaching,dolomitization,paleokarstification, buried dissolution and so on in Tarim, Ordos and Sichuan Basins. The carbonate reservoirs can be divided into four types: (a) atmosphere freshwater leaching reef and shoal limestone reservoir, (b) paleokarstified reef and shoal limestone reservoir, (c)dolomitizied reef and shoal dolostone reservoir and (d)paleokarstified anhydrite dolostone reservoir in these mentioned basins. A comprehensive genesis-prediction model of barrier-related carbonate reservoir is put forward. The reef and shoal zone along platform edge that builds the barrier island is the areas favorable for (a) to(c) typed reservoirs, while the edge flat zone of evaporation basin behind the berrier island is the area favorable for (c) typed reservoir.