Sulige tight sandstone gas field has been in the stable production stage.However

the remaining undeveloped high-quality gas reserves is not sufficient for long term stable production.It is of great significance to utilize potential reservoirs which are below current quality cut-offs

and to evaluate their recoverability to increase gas resources for long term production.Considering that the present reservoir classification criteria is not sufficient

a new comprehensive evaluation criterion of tight sands reservoir is established.Tight sandstone reservoir in Sulige gas field can be divided into 5 categories (6 types)

and the Ⅲ

2

type is the most potential reservoir for future development.The potential reservoir is mainly controlled by their physical properties

which in turn related to grain size.The reservoir is fine-middle grained sandstone which belongs to middle-upper part of high-energy channel bar-braided channel

and middle-lower part of low-energy channel bar-braided channel.6 types of formation pattern and 3 kinds of development modes (indirect

combined and direct) for the potential reservoir are also summarized.Recoverability evaluation reveal the relatively good results for direct and indirect method.This potential reservoir characterization and recoverability evaluation can provide a reliable basis for future potential reservoir development.