中国南方中、古生界海相碳酸盐岩成藏多样性探讨

Diversification of Reservoir Formation about Mesozoic-Palaeozoic Marine Carbonate Rock in South China

中国南方经历了多期构造运动的强烈改造,导致了中、古生界油气演化的复杂性,产生了成因多样、成藏规律复杂的油气藏。按成因分析角度出发,可将南方中、古生界油气藏分成原生油气藏、次生油气藏和再生烃油气藏。储集空间类型有孔隙型(鲕滩和生物礁)、裂缝型、裂缝—孔隙型和孔隙—裂缝型,各储集类型主要受特殊的沉积成岩相带和构造所控制。有效的保存条件及成藏要素在时间及空间的良好匹配关系对南方中、古生界海相碳酸盐岩成藏具有重要意义。指出了未来勘探方向:寻找具有次生、再生烃气源和早期成岩作用过程中遭受淡水淋滤而形成的次生孔隙或海水与淡水混合作用而成的白云石化储层及微裂缝储层,寻找加厚的生储盖组合区域。

South China has experienced intense reconstruction from multiple structural movements and caused complex Mesozoic-Palaeozoic hydrocarbon evolvement,resulting in the formation of oil and gas reservoirs with diversified origin and complex regular pattern.Based on genetic analysis,the reservoirs could be divided into primary reservoirs,secondary reservoirs,and regenerated reservoirs.There are pore reservoir (oolitic beach and organic reef),fractured reservoir,fracture-pore reservoir and pore-fracture reservoir.All reservoir types were mainly controlled by special sedimentary-diagenetic facies and structures.Effective preserving conditions and good match of key elements for reservoir formation in time and space were very important to the reservoir formation of Mesozoic-Palaeozoic marine facies carbonate rock.This paper pointed out the future exploration orientation,i.e.looking for the secondary porosity reservoir leached by fresh water or the dolomization reservoir created by the mixture of sea water and fresh water and microfracture reservoir,looking for the area with the combination of thick source bed,reservoir strata and capping.