江陵凹陷富钾硼锂卤水砂岩储层特征研究

Study on Reservoir characteristics of potassium-boron-lithium-rich Brine Sand Stone,in Jiangling Sag

江陵凹陷古近系液态型卤水矿床蕴藏着丰富的钾锂硼等资源。砂岩是一种重要的储层岩性,而该盆地上白垩统发育厚层的风成砂岩沉积,是否能作为潜在储层是值得关注的问题。以江汉盆地江陵凹陷西北缘的宜昌红花套镇、猇亭和当阳市远安县等地区的露头为研究对象,结合凹陷内白垩系红花套组钻井岩心分析,并与始新统新沟嘴组下段砂岩岩心物性进行对比,研究发现白垩系红花套组风成砂岩分选好,磨圆度高,属中孔低渗储层,与新沟嘴组下段砂岩物性相似。由此可见,江陵凹陷白垩纪的风成砂岩是江陵地区下一步探索富含钾、锂、硼等元素卤水的重要目地层位。

The Paleogene brine deposit in Jiangling Sag are rich in potassium,lithium and boron resources.Sandstone is an important reservoir lithology,and whether the thick aeolian sandstone deposits developed in the Upper Cretaceous in this basin can be regarded as potential reservoirs is a problem worthy of attention.Taking the outcrops in Yichang Honghuatao town,Xiaoting and Yuanan county,Dangyang city,in the northwest margin of Jiangling sag in Jianghan basin as the research objects,combined with the drilling core analysis of the Cretaceous Honghuatao group in the depression,and compared with the sandstone core physical properties of the lower member of the Xin’gouzui formation of the Eocene,it is found that the aeolian sandstone of the Cretaceous Honghuatao group is well separated and has a high degree of roundness,and belongs to the middle porosity and low permeability reservoir,which is similar to the sandstone physical properties of the lower member of the Xin’gouzui formation.It can be seen that the Cretaceous aeolian sandstone in Jiangling sag is the next step to explore the important target horizon rich in potassium,lithium,boron and other elements in Jiangling area.