江汉盆地潜江凹陷潭口地区构造模式及勘探潜力

Structural model and exploration potential in Tankou block of Qianjiang sag, Jianghan Basin

潭口地区属于极具盐湖盆地特色的一个大型盐隆构造,其结构构造十分复杂。近年来通过对潭口地区结构构造及演化开展再认识,认为潭口地区具有盐湖特色的S形嵌入构造。结合已有钻探资料与油气发现,首次明确提出潭口凸起同沉积断层带下降盘发育多期坡折扇体,同时指出该区存在4类重点勘探目标,即潭口凸起周缘构造油藏勘探目标,潭口凸起东、西部滩坝岩性油藏、水下分流河道构造—岩性油藏勘探目标,潭口凸起南部同沉积断层带下降盘坡折岩性油藏及嵌入型构造油藏勘探目标,高断阶带新沟嘴组、白垩系它源油藏勘探目标。

The Tanchou block covers a large-scale salt swell developed within a salt-lake basin, where the structure is very complicated. In recent years, further investigation has been carried out into the structure and evolution in the Tankou block, revealing that this block is an S-shaped embedded structure with the characteristics of salt lake. Based on drilling data and oil and gas discoveries, it is pointed out for the first time that multi-stage slope-break fans are developed in the downthrow side of the syndepostional fault belt in the Tankou bulge, and there are four types of key exploration targets which are 1） structural reservoirs in the margin of the Tankou bulge, 2） beach bar lithologic reservoirs and underwater distributary channel structural-lithologic reservoirs in the eastern and western parts of the Tankou bulge, 3） slope- break lithologic reservoirs and embedded structural reservoirs in the downthrow side of the syndepostional fault belt in the southern part of the Tankou bulge, and 4） the Xingouzui Formation in the high step-fault zone and the Cretaceous separate-source reservoirs.