准噶尔盆地中部下侏罗统三工河组二段沉积相及储层特征

准噶尔盆地中部下侏罗统三工河组二段广泛发育三角洲相。二段下部在研究区东北部以大型辫状河三角洲前缘沉积夹滑动浊流沉积为特征，西部以扇三角洲沉积为特征，在中部两者交汇叠加。二段上部在东北部和西部都为曲流河三角洲前缘亚相沉积，在区中部交汇叠加。三工河组二段砂岩发育大量原生孔隙和次生孔隙，为有利储层。沉积微相类型控制砂体储集性能，成岩作用对砂岩储集性的改造并不强烈。二段下部的辫状河三角洲前缘河道微相及扇三角洲前缘河道微相具有大孔中渗的特点，为Ⅰ、Ⅱ类储层；上部的曲流河三角洲前缘分支河道及前缘席状砂微相，具中孔中、低渗的特点，为Ⅱ和Ⅲ类储层。

Sedimentary facies and reservoir characters of the Member 2 of Sangonghe Formation of Lower Jurassic in Central Junggar Basin

 Delta facies were widely developed in the Member 2 of Sangonghe Formation of Lower Jurassic in central Junggar Basin. During the sedimentary period of the Member 2 of Sangonghe Formation, the northeastern part of the study area was characterized by large-scale braided river delta front with sliding turbidite sediments, while the northwestern part was characterized by fan delta sediments. In the central part, these two sediments jointed together. The Upper part of the Sangonghe Formation was meandering river delta front sediments. A great deal of initial pores and secondary pores were developed in the sandbody, while diagenesis doesn’t revise the capability so strong. The channel microfacies of the braided river delta front in the lower part of Member 2 of Sangonghe Formation is type Ⅰand Ⅱ reservoir with large porosity and middle permeability. The branch channel and fleet sandbody microfacies of meandering river delta front are type Ⅱand Ⅲ reservoir with middle porosity and middle to low permeability.