| By the end of 2005, reserves of the global carbonate reservoirs is more than 50% in general,which is the total reserves of large oil and gas pools in the world. Large carbonate oil and gas pools emerge in the recent 10 years, such as Puguang gas field, Yuanba gas field, Tarim Ordovician oil pool et al., which show the great exploration prospect of domestic carbonate reservoir. The carbonate reservoir is the second important one in the exploration of oil and gas pools besides sand reservoir in the northeastern South China Sea hydrocarbon basin, and its exploration potential is huge. After 30 years hydrocarbon exploration, a lot of carbonate(reef) Oilfields are founded in the Pearl River Mouth basin.For example, the biggest carbonate(reef) Oilfield in the coastal area of China,named LH11-1 oilfield, is founed in the Pearl River Mouth basin. Howevere, there is no prominent development in the large carbonate(reef) Oilfield of the Pearl River Mouth basin in recent 10 years. The reason is that the general structural traps of the carbonate reservoirs are few, and the lithologic trap study of carbonate reservoirs is short. Moreover, the distribution of carbonate reef-flat reservoir is more complex, and the reef is confused with volcanoes and mudlump. In fact, the regularity and identification of reef is much poorer, so its research difficulty is obviously apparent.It is universal research method for the carbonate reefs and shoals reservoir by carbonate sequence stratigraphy, carbonate facies and carbonate diagenesis in petroleum geology, which has a strong guiding significance for the exploration and development of carbonate pools. It requires a large lot of geological basic data, such as wells, core,rock slice and outcrop data. However, many geological basic data is very short because of the high cost of offshore drilling,which has brought great obstacles to the marine carbonate rock reservoir comprehensive study.Because of the special geological conditions of the sea, this paper try to explore a set of method to analyze carbonate reservoir comprehensive research,according to sequence stratigraphic(mainly based on Seismic Stratigraphy), seismic facies, reservoir prediction methods and seismic sedimentary image. It uses utterly the vertical and horizontal resolution of the 3D seismic data, taking the sequence interface analysis, rock type analysis and rock physical analysis into account of the basis for prediction of carbonate reservoir. The distribution of Carbonate reefs and shoals reservoir is analyzed by both inversion technology that is controlled by the multi-information fusion sedimentary facies and seismic sedimentology research; carbonate reef-flat reservoir finely described horizontally and vertically; using well lithology calibrate seismic sedimentary image, which can obtain reliable favorable range and distribution of carbonate reef-flat reservoir. In short of wells and geological data, this research method make full use of the limited geological data, well data and 3D seismic data,which is to reduce the excessive dependence of geological data on the basis of simple geological research method.Favorable reservoir facies belts are identified by the application of above carbonate reservoir prediction method in the study area, which contains carbonate reefs and shoals from the margin and the inner of the platform. The distribution of carbonate reefs and shoals,of the inner of the platform is wide, which is over 100 square kilometers and 85 m thickness. Carbonate reef of the platform margin is more than 40 square kilometers and over 50 m thickness. Combining with the characteristics of structure,cap rock,oil and gas migration,and hydrocarbon,the two favorable exploration targets are analyzed comprehensively. Target I possesses the characteristics of large structural lithologic complex trap, which has great potential prospect and provides useful method and reference ideas for the marine carbonate reservoir researc. |
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