Analysis of Water-Flooding Development Potential for Tight Reservoir in the Ordos Basin

A series of calculations using the basic formulas can clarify the development potential of tight reservoirs, which is a meaningful study. Water-flooding is a widely used method for developing tight reservoirs, and as such, analyzing the potential for water-flooding and selecting an optimal development method are crucial for successful reservoir development. Based on the varying fluid flow states during the development of tight reservoirs, the ultimate permeability can be categorized into three types: ultimate imbibition permeability (Ki), ultimate displacement permeability (Kd), and ultimate displacement development permeability (Ku). The ultimate permeability of the tight reservoir in the Ordos Basin was calculated through the ultimate permeability calculation method and the basic parameters of the tight reservoir. According to the results of the ultimate permeability calculations for different tight reservoirs in the Ordos Basin, it was found that the permeability of the reservoirs (0.1 mD–1 mD) was higher than Ki (0.0034 mD–0.084 mD), but between Kd (0.236 mD–0.526 mD) and Ku (0.4691 mD–1.167 mD). Therefore, the potential for developing the tight reservoir in the Ordos Basin by the imbibition-displacement method during water-flooding was significant. Among all the tight reservoirs analyzed, Chang-6 has a greater potential for displacement development, whereas Chang-4 + 5 has a lower potential for imbibition development. However, its potential for imbibition-displacement development is higher. By analyzing the water-flooding development potential of tight reservoirs in the Ordos Basin from the perspective of ultimate permeability, this study can serve as a reference for selecting optimal development methods and identifying the difficulty levels associated with tight reservoir development.