Abstract: Under the background of low oil price, the effective upgrading and utilization of the inferred initially in-place petroleum reserves are essential. At present, there is a large quantity of existing inferred initially in-place petroleum, but there is no systematic study on the evaluation of the upgrading potential. In this paper, a funnel screening method is used to establish a clear and effective evaluation procedure and to focus on the evaluation and control of risks in each stage of the process. In order to minimize the influence of human factors in geological risk assessment, the technique for order preference by similarity to an ideal solution (TOPSIS) is used to evaluate the geological factors that affect the reserves upgrading for the first time. Eleven potential upgrading blocks have been selected and achieved good results in clastic rock reservoirs in the Bohai Bay Basin. The research results show that the uncertainty of the predicted reserves is large. In the upgrading process, the risks and difficulties should be identified in time. The corresponding technical measures are taken and the strategy are proposed, which provides guarantee for the further efficient and economic upgrading of reserves.