塔里木盆地塔中地区奥陶系碳酸盐岩储层成因类型、特征及油气勘探潜力

塔里木盆地塔中地区奥陶系碳酸盐岩油气探明储量近1.5×108t,而且仍有巨大的勘探潜力,储层属性一直被认为是礁相储层。通过76口探井的岩心观察,完井地质报告、试油成果的分析,铸体薄片的鉴定,尤其是对有工业产能的20多口探井试油井段近500个铸体薄片的详细鉴定和复核,指出塔中地区奥陶系碳酸盐岩有效储层类型复杂多样,有泥亮晶棘屑灰岩、层间古岩溶和古潜山风化壳型储层,分别与沉积间断面、平行不整合面、角度不整合面相关。虽然发育了小规模的礁丘体,但不是有效储层,更不可能形成规模效益储量。储层属性的重新认识对塔中地区勘探潜力的重新评估和勘探理念的转变均具重要的指导意义。

Genesis Classification and Characteristics of Ordovician Carbonate Reservoirs and Petroleum Exploration Potential in Tazhong Region, Tarim Basin

Ordovician carbonate rock possesses near 150×106t of proved oil reserves in Tazhong Region in Tarim Basin. The Ordovician reservoirs is commonly taken for reef facies. Depend on the various data of from 76 wells, especially the deal observation and checking to near 500 molding thin sections from more than 20 industrial wells, it is pointed that there are various and complicated effective Ordovician carbonate reservoirs in Tazhong region, including micritic/spiritic echinoderm limestone reservoir, interbedded paleocarstic reservoirs and buried paleohill reservoirs, which are respectively relative with sedimentary hiatuses, parallel unconformities and angular unconformities. Small scale of reef mounds developed in this area but they are not effective reservoirs, and even, in which large-scaled available reserves hardly so much as forms. The re-recognizing the attribution of these reservoirs is significant of re-estimating exploration potential and changing exploration conception.Ordovician carbonate rock possesses near 150×106t of proved oil reserves in Tazhong Region in Tarim Basin. The Ordovician reservoirs is commonly taken for reef facies. Depend on the various data of from 76 wells, especially the deal observation and checking to near 500 molding thin sections from more than 20 industrial wells, it is pointed that there are various and complicated effective Ordovician carbonate reservoirs in Tazhong region, including micritic/spiritic echinoderm limestone reservoir, interbedded paleocarstic reservoirs and buried paleohill reservoirs, which are respectively relative with sedimentary hiatuses, parallel unconformities and angular unconformities. Small scale of reef mounds developed in this area but they are not effective reservoirs, and even, in which large-scaled available reserves hardly so much as forms. The re-recognizing the attribution of these reservoirs is significant of re-estimating exploration potential and changing exploration conception.