Abstract: Carbonate sequences contain sequence boundaries of various orders and genetic types. Accordingly, the development of the carbonate reservoirs was controlled by various geological processes in association with those sequence boundaries. In general, the sequence boundaries could be categorized into six orders according to the magnitude of tecto-nic movement, and the relative range and the duration of sea level change. Among these boundaries, the sequence boundaries of higher orders of (Ⅰ to Ⅲ) correspond to various unconformities, while that of the lower orders correspond to flooding surfaces or local deposition events. The formation of the scaled karst reservoir was controlled by the I- and II-order sequence boundaries, and the ancient geomorphic location of the karst landform had the most significant effect on the formation and preservation of the reservoir. There was a clear deviation between the degree of the reservoir development and the controlling factors of karstification in various ancient geomorphic locations. As a whole, the karstification was relatively weak in the third-order sequence boundary with a limited reservoir distribution, but was still closely related to the formation and distribution of the platform margin and the reef flat face. There was a dual-control on both the deposition and diagenesis by the third-order boundary as well. The exposure times were relatively short in the fourth-order and fifth-order sequence boundaries. As a result, large scale reservoirs were rare due to the lack of post-diagenesis effect. The types and orders of the sequence boundaries have various influences on the formation and distribution of the carbonate reservoir owing to different geological processes. Thus, the prediction and evaluation of the carbonate reservoirs could be carried out by the fine division of sequences, recognition and description of the sequence boundaries. However, the deposition filling pattern, facies belts distribution, structural deformation and fluid movement should also be taken into consideration.

Key words: order of sequence boundary, type of sequence boundary, carbonate rock, quality reservoir