关键词: 裂缝, 发育期次, 稳定同位素分析, 流体包裹体, 苏德尔特构造带, 布达特群

Abstract: In recent years, along with the hydrocarbon exploration of peripheral basins in the Daqing oilfield, the buried clastic hill reservoirs are found in the Budate Group in the Sudeerte structural zone of the Hailaer Basin. The reservoir space for oil-gas is mainly related to structural fractures. It has been found that the form, development and evolution of fractures have great influences on oil-gas concentration. Based on observation on bores and on analyses on the regional structural evolution history and thermal evolution history, the development periods of the fractures are searched by stable isotopic analysis, fluid inclusion homogenization temperature of in-filled components in fractures and acoustic emission technology. The results indicate the fractures in the Budate Group are of multiple-episodes and of inherited development. Three stages of fracture development have been identified. The fracture activities of the stageⅠare related to the Nantun-Damoguaihe movement and are filled by quartz mainly formed under temperature between 72℃ and 76℃. In this stage, hydrocarbon inclusions are found but their maturity is low. The fractures of stageⅡare the products of regional extension of the Yimin phase and are filled by calcite and microcrystalline quartz, both formed at 117℃ to 154℃. Generally, the hydrocarbon maturity of this stage is relatively high. The fractures of stage Ⅲ came into being during intense uplift at the end of the Yimin period. These fractures are filled by microcrystalline calcite and quartz formed at 89℃ to 110℃. The hydrocarbon maturity of the stage lessened.

Key words: fractures, development period, stable isotope analysis, fluid inclusion, Sudeerte structural zone, Budate Group