Abstract: The marine carbonate reservoir in Tazhong uplift in Tarim basin is characterized by complicated geology and surface conditions, and its petroleum exploration faces challenges in world-level difficulties. After 15-year researches and practices, the hydrocarbon accumulation theories for marine carbonate reservoirs have been developed, such as the reserves- and hydrocarbon accumulation-controlling theory, the geologic model for multi-origin superimposed and complex fractured-vuggy system, the multi-charging location and multistage large-scale complex mixed sources accumulation theory. The matching technologies for marine petroleum exploration and development are created, including super-deep carbonate rock seismic gathering and processing in desert region, quantitative imagery of fractures and caves, hydrocarbon detection, allocation of high- and stable-production wells, drilling and completion technologies for super-deep and high-temperature carbonate reservoir, and large acid fracturing and alteration technology for fractured-vuggy carbonate reservoir. By means of these theories and technologies, a billion-ton-grade condensate gas field of the Ordovician carbonate reservoirs in Tazhong uplift has been found out, proving the first reef flat complex oil-gas field of Ordovician in China, from which 300 million tons of reserves have been proven basically, and one million-ton productivity has been built up comprehensively. Also, a large scale condensate gas field with interlayer karst of Yingshan formation in the northern slope of Tazhong uplift has been discovered, from which 700 million tons of reserves could be determined, and 4 million-ton productivity construction has been completely started up. These evolutional achievements enrich the marine hydrocarbon theory and promote the progress of the key technologies.

Key words: Tarim basin, marine carbonate rock, reef flat complex body, hydrocarbon accumulation theory, Ordovician, Tazhong area