江汉盆地盐湖碳酸盐岩成藏条件及潜力——以新沟地区新沟嘴组下段Ⅱ油组为例

在物源、古地形、古气候的控制下,江汉盆地新沟嘴组下段Ⅱ油组自北而南发育有砂岩相、泥岩相、碳酸盐岩相、硫酸盐以及氯化盐岩相,盆地中南部斜坡带为碳酸盐岩的主要分布区,具有碳酸盐岩与薄层泥岩频繁互层沉积特征;其中碳酸盐岩晶间孔发育,具有较好的储集条件,泥岩有机质丰度高,具有较好的生烃能力,生储配置关系良好;新沟嘴组下段Ⅱ油组碳酸盐岩成藏条件优越,油气成藏主要受有利烃源岩分布范围、岩性岩相、物性控制,具有烃源岩控藏、岩性物性控富的特征;江汉盆地碳酸盐岩油藏分布广泛,具有较好的勘探开发前景。

Probe into Accumulation Condition and Capacity of Carbonatite in Saline in Jianghan Basin

A variety of lithofacies such as sandstone, mudstone, carbonate, sulphate and chloride are devel- oped from north to south in Group Ⅱ of lower member of Xingouzui Formation in Jianghan Basin under the control of source, ancient landform and paleoclimate. The carbonate rock is mainly distributed in the slope belt of south--central basin, characterized by repeatedly intercalated carbonate and laminated mudstone de- posits. There are rich intergranular pores in the carbonate rock implying favorable hydrocarbon accumulation conditions, and high abundance of organic matter in mudstone is responsible for good hydrocarbon--genera- tion capability. Source rocks are well matched with reservoirs. The carbonate rock in groupⅡ is favorable for hydrocarbon accumulation, which is mainly controlled by the distribution of source rocks, lithology and lithofacies and physical properties, with the characteristics of the source rocks controlling hydrocarbon accu- mulation, and lithology and physical properties controlling hydrocarbon enrichment. The carbonate reser- voirs are widely distributed in Jianghan Basin with good exploration and development prospect.