西藏伦坡拉盆地下第三系储集层类型与特征

Type and feature of Lower Tertiary reservoirs in Lunpola basin.

西藏伦坡拉盆地下第三系储集层分为孔隙性储集层和裂缝性储集层两大类。孔隙性储集层为盆地内最主要的储集层类型，以扇三角洲平原相和水下分流河道相储集物性最好，次为滩坝相；裂缝性储集层平面分布受控于断裂系统和局部构造，纵向上主要发育在牛堡组三段和牛堡组二段上亚段。该区储集层物性受控于沉积环境和成岩作用，自丁青湖一段到牛堡组一段，成岩作用相对愈强，储集物性相对愈差，较好的储集层主要分布在盆地南、北构造带，但由于受后期强烈改造，其有效性变差，中央凹陷带物性总体较差，但局部相对较好，尤其是扇三角洲发育区。该区裂缝性油气藏的勘探应以牛二段中亚段为主要目的层。图１参４（邹冬平摘）

The Lower Tertiary reservoirs in Lunpola basin can be divided into pore type and fracture type. The former is the main reservoir type. Among it, fandelta plan facies and subaqueous distributary channel sandbody have the best physical property and the secondary is beach bar facies. The distribution of fractured reservoirs which primary developed in E2n3 and E2n 22 is controlled by fault system and regional structure.