Abstract: Core observation, thin section identification, and physical property analysis show that the carbonate reservoir quality of the Lufeng, Huizhou, and Liuhua areas in the Pearl River Mouth Basin is significantly different. The carbonate reservoir quality of the Huizhou area is the lowest of the three areas because of extensive cementation; the reservoir has a visual porosity and an average permeability below 1 mD. Extensive dissolution, including early meteoric and burial dissolution, generates a great amount of secondary porosity, such as intergranular pores, mold pores, alter-large pores and geode pores, in the Liuhua area, which contributes to more than 80% of the whole thin section porosity. The carbonates of this area have the highest porosity and permeability, high porosity and permeability correlation coefficient, and low cutoff porosity. Therefore, the best carbonate reservoir was developed in the Liuhua area. Early cementation is very helpful for the preservation of the primary porosity in the Lufeng area, where the dissolution is much weaker than in the Liuhua area, which makes the porosity in the Lufeng area approximately equal to that of the Liuhua area. However, its permeability is much lower than that of the Liuhua area due to the low connectivity of the primary porosity and the cutoff porosity is the highest. Thus, the Lufeng area is characterized by medium carbonate reservoir quality.

Key words: reservoir characteristics, diagenesis, reservoir quality, Zhujiang Formation, Pearl River Mouth Basin