Abstract: Practical oil and gas exploration in carbonate strata has proved that gypsum-salt rock plays an important role in hydrocarbon generation and accumulation. In this paper, the effect of gypsum-salt environment on hydrocarbon generation, reservoir-forming and hydrocarbon accumulation in carbonate strata was discussed through experiments. As for hydrocarbon generation, evaporative tide flat and lagoon are favorable sedimentary environments for the formation and preservation of source rocks. The modeling experiments on hydrocarbon generation potential of gypsum-salt rock-kerogen assemblage verify that gypsum-salt rock can promote hydrocarbon generation of source rocks remarkably. As for reservoir-forming, the dolomites coexisting with gypsum-salt rocks are the main reservoirs. The formation of evaporative tidal dolomite reservoirs is mainly controlled by supergene dissolution of atmospheric freshwater, and the quality of dolomite reservoirs can be improved effectively by burial dissolution. As for hydrocarbon accumulation, gypsum-salt rocks turn from brittle to plastic withi higher sealing capacity as the burial depth increases, which is favorable for the perservation of deep oil and gas. Physical modeling experiments on structural deformation reveal that, in the setting of compressional structures, discordant fold deformation occurs in presalt and subsalt layers and effective hidden traps are developed in deep layers, so large-scale oil and gas accumulaiton can be formed.

Key words: gypsum-salt, carbonate, source rocks, reservoir, hydrocarbon accumulation