【摘要】 塔里木盆地奥陶系碳酸盐岩潜山主要存在地表及地下两种古水系。两类古水系与潜山碳酸盐岩岩溶型洞缝储层的发育及分布有着密切关系。地下水系控制着大型溶洞的分布,对后期溶洞垮塌、形成顶部大型垮塌裂缝具有重要作用;地表水系在潜山高部位以侵蚀作用为主,在潜山低部位以侧向、纵向溶蚀作用为主,但都能在河床底部及两侧形成较深的溶蚀,并且在成岩作用过程中,由于后期充填物的差异性压实而形成裂缝。同时这两类古水系在演化过程中,都对潜山裂缝起着扩溶作用,以形成更大的岩溶洞缝体系。在潜山区古水系研究过程中采用了古地貌恢复法、地震属性法、频谱分解法、分方位叠前裂缝预测法等方法。更多还原

【Abstract】 There are two patterns of palaeodrainages,the surface ones and the underground ones in Ordovician carbonate buried hills in Tarim Basin.They are closely relative with the distribution and development of caved and fractured karst reservoirs in buried hills.Underground drainages controls the distribution of large-scaled caves and has a great influence upon huge cracked fractures at the top caused by cave collapse during late phase.Surface drainages are generally erosive in high parts of buried hills and generally solvent in lateral or vertical in low parts while they can be solvent at the two sides and the bottom of drainages.Surface drainages can induce to form fractures due to differentiate compaction of fillings during late diagenesis.During development and evolution of the two patterns of palaeodrainages,they meanwhile play a role of enlarging dissolution to fractures so as to form larger scaled karst cave/fracture system.In the process of researching palaeodrainage patterns in carbonate buried hills,some key research methods are applied,such as the paleogeomorphic construction,the seismic attribute analysis,the frequency division processing,and the azimuth division prestack fracture detection.更多还原