摘要：

 沙河街组二段是辽河盆地西部凹陷的主力含油层系，以扇三角洲前缘砂体为主要油气储集体，其油气的富集程度除与丰富的油源条件和良好的圈闭条件有关外，主要取决于沉积储层条件。不同的沉积微相，沉积水体条件不同，形成的砂体粒级、分异性及孔隙结构不同，原生孔隙发育条件不同；埋藏过程中所发生的各种成岩作用进一步改变或改造着扇三角洲砂体的储集性能。压实、胶结等破坏性改造使储层孔、渗性明显降低；溶解、溶蚀等建设性改造有利于深层储层储集性能的改善。探索原始沉积条件、成岩作用与储集性能及含油气性的关系，并进行综合评价和有利储层预测，对研究区油气勘探起到了重要的指导作用。

Abstract:

Sha2 formation of Yuanshuang area is one of the main oil-bearing series in West Liaohe Depression.The main oil reservoir is fan-delta front sandbodies. Sedimentary and reservoir property decide oil(gas) accumulation besides plenty of oil sources and good trap condition. Different sedimentary microfacies and hydrodynamics resulted in different sandstone grainsize,sorting and porosity structure. The diagenesis during deep burial changed the reservoir character of fan-delta sandbodies to some extent . Compaction and cementation lowered the porosity and permeability.Solution and dedudation obviously improved the porosity and permeability. The relationship between oil/gas bearing properties and original depositional condition , diagenesis and petrophysical property are studied In this paper, Synthetical evaluation and prediction of advantageous reservoir area were carried out to Sha2 formation,this directs the exploration of the study area greatly.